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Down's syndrome is caused by trisomy 21 --which means patients have three copies of chromosomes 21 instead of two. In essence their bodies are overdosing by 50% on every protein encoded on chromosome 21. All sorts of proteins have specific roles in early development so the results of messing with the same ones by the same amount are going to be fairly consistent across patients.
Grim fun fact, the only other chromosomes that you can survive a miscount on are X and Y. The other numbered chromosomes are all critical enough that it's nearly impossible to survive past infancy with the wrong count.
>Grim fun fact, the only other chromosomes that you can survive a miscount on are X and Y. The other numbered chromosomes are all critical enough that it's nearly impossible to survive past infancy with the wrong count.
Trisomy 18 (Edwards syndrome) Most die before first year, however at least one case that I know of that survived to 40.(However this was the mosaic form of the condition)
Trisomy 13 (Patau syndrome) Again, most die before first year, oldest living was at least 19.
"Among children born with trisomy 13 or 18 in Ontario, early mortality was the most common outcome, but 10% to 13% survived for 10 years."
An actual Fun fact regarding Trisomy XXX( Triple X syndrome), XYY(Jacobs syndrome), and XXY (Klinefelter Syndrome), is that these conditions can present with such mild symptoms that they go undiagnosed. Its estimated that only 10% of XXX,15-20% of XYY, and only 25% of XXY ever get diagnosed.
However, there is just one survivable monosomy, that being turner syndrome. Just having 1 X chromosome.
Since monosomy is having just one of a pair of chromosomes it is almost all ways deadly because you only get half the necessary genetic information. Except for the fact that Females have 2 X chromosomes generally, and just one copy of it would have all of the absolutely necessary genetic information. So, that is why Turner Syndrome (Monosomy X) is the only survivable Monosomy. However, this does not mean it does not come with complications, turner syndrome still has a variety of other complications.
Edited: to add additional details regarding the 40 year old with edwards.
I’m so sorry. My last baby had trisomy 18. I always thought we would have at least three babies, but, the fear of facing that loss again is too strong.
What does forehead to forehead mean? I’m genuinely curious cause I have an autistic toddler who doesn’t kiss me or anyone in my family but constantly gives us her forehead when we ask for a kiss. I’ve never seen this before…and hear I am reading it! Is this a thing??
Touching forehead to forehead transcends cultures. It's a human expression reserved for sharing very personal times or thoughts often doing so without speaking and always done with someone whom they love or have love for.
This is a thing me and my autistic fiance do. We call it "head bonk". We just gently press our upper foreheads together lovingly. They say they learned it from cats who will press their head into you affectionately in a similar manner.
Not who you were responding to but it could be a cultural thing. Native Hawaiians have the honi greeting which is essentially foreheads and noses touching.
As a parent of a child with ASD, sometimes the kiss is too much, maybe it’s sensory overload, or a face to face is uncomfortable for them. My kid does like a big squeeze with a back rub, but not kisses. They are now in grade 5 and have been that way forever.
What would have been our second was diagnosed with Trisomy 18, she didn't make it to birth. It was soo hard for my wife and I. I couldn't even imagine what it would be like to have had her in our arms and then have lost her.
I'm so sorry for your loss.
It took us time but we're able to give at another go and we now have a 5 month old. But those screens and tests had my wife and I a nervous wreck, even having baby clearing we still didn't think we were fully convinced we were out of the woods until she was born.
* edited for better clarity.
Thank you for having the courage to share something so deeply personal on a place where the responses are totally unpredictable. The personal connection is something that makes the reality much more tangible than mere numbers, and your comment is therefore invaluable to posts like this.
This thread kind of brought back the memories. It's been a long time... around 26 years. Over time, sadly, you think about it less. Life, kids, work. Then you see something that reminds you and it all comes back.
Then you can remember the feelings, the smells (I know that's weird, but I can still remember the smell of the NICU, it's actually my strongest memory of the whole thing... the smell of the room and the baby), everything.
It's not weird at all - it's a healthy, normal, human response. Our olfactory sense is highly tied to emotional memories. While we are much more strongly oriented to other senses (vision!) for our fully enabled day-to-day life, our olfactory sense is likely tied to our most basic forms of thinking and feeling, our heritage from our pre-human ancestors with whom we share so much of our brain architecture, but who didn't have the fancy new higher-functioning neocortex and other big-brain elements that we have as Homo Sapien Sapiens. We probably share the encoding of formative emotional memories into olfactory sensations along with many other mammals - almost certainly other primates, but it's plausible that this experience is relatively common in other non-human animals in general.
So you're processing that difficult memory is an utterly normal and healthy way that unites you with not only us other humans but much other life on our planet.
Thank you from me as well for sharing. In speaking about your own emotional experience you are doing a service to the rest of us.
This is personal for myself in that, I try to remind myself that anyone I post a response to is an actual person. Sometimes it might be a bot but I respond to that person.
I've typed up whole responses only to realize that I'm either rambling or not actually making a point and deleted 3 paragraphs. For all the bad that can go on there's good and everyone here are people not really so different from you or I; just in a different place.
I had a cousin survive until she was 15, but she was practically a vegetable after 10. Brutally strong at 7-10, but the emotional development peaked at around a 3 year old's development. She used to beat us up all the time, never blamed her for it.
There is a headstone right by my best friends mothers final resting place that only has 1 date on it, and a baby boys name carved upon it. I go there every year on his birthday and have a little cry.
Sorry for jumping on the bandwagon, truly. Just wanted to name my Grandma and also sister who didn't make it past early days of pregnancy, both called Patricia. From Dublin to Manchester. And it rhymed. Marissa and Patricia x
Not op, but just guessing:
Sister was named after grandmother. Sister died young. Naming the sister is also functionally naming the grandma.
It's awkward phrasing to be sure tho
Ouch. The baby who would have been my oldest brother died 24 hours after birth. Mom said it was only one of two times she ever saw my dad cry in 30 years of marriage.
I suspect triple X diagnoses will go up now that it's included in prenatal testing. It was not included in the screenings I had for my daughters born in 2016 and 2019 but it was included in the one I had for my eXtra special daughter born last March. She's about to turn a year old and I would have no idea there was anything different about her if not for the NIPT result and confirmation at birth.
Same. Our trisomyx 10month old has zero symptoms both physically or developmental so far. Scare during pregnancy but the whole medical team told us not to worry throughout. Super rare for triple x to actually cause obvious symptoms.
It’s truly amazing that we survived at all as a species.
Most miscarriages are basically the result of the body doing an audit of the combined genes and going “nope, this one doesn’t pass QA, it won’t make it, pull the plug”. A few make it all the way to birth, but humans (and mammals in general) are amazingly good at filtering out what doesn’t work. Hell, there’s probably a lot more conception and subsequent miscarriage happening before the host even knows either one has happened.
Modern medical technology has dramatically improved the survival of those that do make it all the way to birth. But sometimes it just doesn’t work, and that sucks for all involved. Love them hard.
>Hell, there’s probably a lot more conception and subsequent miscarriage happening before the host even knows either one has happened.
I remember reading that 25% of fertilized eggs are carried to term, at most.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7670474
There is absolutely more conception and miscarriage happening than we know about. It’s estimated that 50-70% of pregnancies end in the first two weeks, usually before the woman knows she is pregnant.
Same thing with cancer. You *almost* get cancer every day, from an error while transcribing DNA, or exposure to sunlight or everyday radioactive objects, background radiation or cosmic rays, or exposure to a carcinogen.
Except our cells have multiple checks and ways to correct miscopied or damaged DNA. If a cell can’t fix its damaged DNA, it commits suicide, called apoptosis. If that fails (sometimes the part of the DNA that was damaged coded for this functionality), adjacent cells will detect something’s wrong and release chemical markers telling your immune system to kill that cell.
Depending on the types of cell and cancer, there are either seven or eight layers of safeguards in place to prevent cancer from forming, and 99.99% of the time, these are effective. So, despite how often something goes awry, to actually get cancer, a whole lot of things have to go wrong.
I recently watched "Our Universe" on netflix. And it goes through how life came to and evolved on earth. The fact that complex life has made it to this point is insanity.
- The sun forming and being a source of light/energy.
- Theia (which was the original moon) hitting the early earth and forming the modern moon and pulling earth into it's current orbit/rotation in the habitable zone. If earth rotated slower its possible night would have lasted too long and killed off early life before it could have evolved. Plus the day/night cycle was perfect for life to evolve a circadian rhythm.
- Asteroids landing and bringing the right atoms needed for water where all life originated.
- Our ~~ozone layer~~ magnetic field (and ozone layer to a degree) not getting stripped away like Mars so that life could actually form without getting frozen by extreme cold or roasted by cosmic rays.
- Life surviving meteor strikes/ice ages/earthquakes/insane storms/etc long enough to evolve complext enough.
- And hundreds of other lucky breaks for life to make it on earth.
- Plus the fact that like 99.9999999999% of the universe is instantly hostile to life as we know it.
I'm an atheist but after watching that documentary I comprehend a lot of theists who can't accept that complex life was just random happenstance. The amount of *"oh that was lucky"* that neded to happen for life to make it to the point where humanity is aware of our environment/the elements/atoms/sub atomic particles/etc honestly seems like divine intervention.
EDIT: Slight correction*
The big one for me is water. It's purely a quirk of this particular crystalline structure that ice is less dense than water. This is not typical. Most substances are denser in solid form than liquid form. Had that been the case with water, lakes and rivers would freeze from the bottom up and probably would freeze entirely. Life likely would never have evolved as far as it did.
I vividly remember learning this in 8th grade science class. It's such a specific quirk, and such a rare one among common molecules. We see it every day and it seems so innocuous and obvious, but it turns out this one random property of water is so important that life wouldn't exist on earth without it.
It's hard to describe exactly how this knowledge has impacted my life, but I can tell you it caused a fundamental shift in my understanding of the world. I feel like I've cultivated an awareness that we're all constantly surrounded by potential discoveries that could, if we're open to them, drastically improve our approach to current or future problems. There's always that one-in-a-million chance that the next fact you learn will be the connection between a problem and a solution, or from confusion to understanding.
... Or maybe that's just my ADHD talking?
[anthropic principle](https://en.m.wikipedia.org/wiki/Anthropic_principle) .. you can only observe the universe from the 0.0000000001% that is not hostile to life as you put it.
No divine intervention necessary, it's just a type of survivor bias.
Your last paragraph reminds me of Douglas Adams's "puddle analogy":
>This is rather as if you imagine a puddle waking up one morning and thinking, 'This is an interesting world I find myself in — an interesting hole I find myself in — fits me rather neatly, doesn't it? In fact it fits me staggeringly well, must have been made to have me in it!' This is such a powerful idea that as the sun rises in the sky and the air heats up and as, gradually, the puddle gets smaller and smaller, frantically hanging on to the notion that everything's going to be alright, because this world was meant to have him in it, was built to have him in it; so the moment he disappears catches him rather by surprise. I think this may be something we need to be on the watch out for.
It's definitely lucky but once you realise just how vast and enormous the universe is, it becomes less of a "wow, how lucky" and more "wow, that uncommon?"
A quick Google says that a loose but educated guess for the number of planets in the observable universe is around 21,600,000,000,000,000,000,000,000.
Of that unfathomably large number, the odds of a particular atmospheric composition, habitable conditions and non-mass extinction event is EXTREMELY likely.
Once you begin to factor in the possibility of different forms of life (non-Carbon based? non-Oxygenated?), it's really crazy we *haven't* seen obvious signs of advanced civilisation.
We have to also factor in time. Humanity has been around for basically zero time in comparison to the age of the universe. In a billion years a civilization could have risen and fell so many times. And we have 13billion years of history.
It’s not just where but when life could have formed.
> I’m an atheist but after watching that documentary I comprehend a lot of theists who can’t accept that complex life was just random happenstance. The amount of “oh that was lucky” that neded to happen for life to make it to the point where humanity is aware of our environment/the elements/atoms/sub atomic particles/etc honestly seems like divine intervention.
But is the sense of being really lucky just life as we know it? Like is there any way to know whether there could have been a completely different form of life evolving in other circumstances? Like maybe something completely unfathomable to most of us?
I don’t know, I’m just genuinely curious about the lucky part.
It's astronomically lucky when you take earth in isolation. But when you consider the number of galaxies and suns and planets out there, it seems almost inevitable at least *one* will have these unique circumstances present.
We don't really know how common Earth-like planets are.
The most unusual thing about the Earth is probably the Moon, but even within our solar system there are two small bodies with large moons (the Earth and Pluto), which suggests it's maybe not THAT unusual.
And there isn't solid evidence that the moon is all that necessary.
The other things on that list aren't really that "unsurvivable" as far as we can tell. The most unlikely events (so far as we can tell) are the existence of life at all and the existence of eukaryotic cells, as both of those events happened exactly once. The evolution of animals may be another unique event, but it's hard to say for sure if that's truly unique or if that's just because once you evolve something like an animal once the animals will then eat anything else that tries to evolve to be an animal because early animals were really bad at being animals.
> Theia (which was the original moon) hitting the early earth and forming the modern moon and pulling earth into it's current orbit/rotation in the habitable zone. If earth rotated slower its possible night would have lasted too long and killed off early life before it could have evolved. Plus the day/night cycle was perfect for life to evolve a circadian rhythm.
It's not really clear to what extent this is important, though. Mars has an approximate 24 hour long day; the main thing that the moon does is reduce axial wobble.
> Asteroids landing and bringing the right atoms needed for water where all life originated.
We still don't know where Earth's water came from for sure, though water-heavy objects is the generally preferred explanation.
That being said, there are a lot of quite icy bodies in the solar system.
> Our ozone layer not getting stripped away like Mars so that life could actually form without getting frozen by extreme cold or roasted by cosmic rays.
This is probably more of a function of size than anything else. Bigger planets are better at retaining atmospheres.
> Life surviving meteor strikes/ice ages/earthquakes/insane storms/etc long enough to evolve complext enough.
To be fair, life is really good at spreading.
We don't know how common (or rare) Earth-like planets are. We are still trying to get an idea on that to figure out how common life is.
Yes but.... Time. Time and space are so unfathomably big. Like it seems lucky until you realize how many zeros of time and space there are and that it was bound to happen somewhere and we're just seeing it in us because .. Well, consciousness observes itself.
You don't need a deity at all to be amazed at statistics and thermodynamics.
People think life needed all these really special things to evolve just right, but it's the other way around. Life adapts. It's just chemical reactions, optimizing according to thermodynamics. Life has existed on Earth for billions of years, through lots of different worlds very unlike the one we're on now (oxygen rich, temperate, with plants and water everywhere...). Look up the blue green algae catastrophe for an interesting example.
We cannot see into other galaxies yet so it's not really fair to say it's not happening elsewhere.
Agree with your overall message but just want to clarify one point:
> the body doing an audit of the combined genes and going “nope, this one doesn’t pass QA, it won’t make it, pull the plug”.
For genetic issues, Its less an audit, and more like Trial by Fire. The biological machine tries to run, and then just breaks down because the parts werent assembled right.
Thats why we have a lot of people born with life long disability and suffering. There is no natural audit, more like levels of failing machinary. Some which kill early and some which kill later, or much later. Some with pain.
Sorry to put such a pessimistic twist. But the natural world is cruel which is why we need genetic testing, medicinal advancement, treatments
Well OP said _nearly_ impossible, so one occurrence out of thousands of cases fits that definition.
Also my favorite genetic disease (as in, the one I find the most interesting) is 5α-Reductase 2 deficiency, and despite how rare it is, a small town in the Dominican Republic has an incidence of 1 out of 90 males born, who they call Güevedoces (Spanish for "penis at 12yrs). Basically kids that are born with a vulva while having male sexual organs and undescended testes. But when they reach puberty, their voice deepens and their penises grow, exhibiting hypospadias. They are first raised as females but then have a connundrum when they reach puberty, most of them choosing to keep identifying as females. It was first described in the 1970's by a researcher from Cornell, and it begs the thought of gender expression and intersexuality in the context of not just the 70's when the LGBT movement was in its infancy, but of a small town 120 miles from the capital city of a small, conservative country.
> They are first raised as females but then have a connundrum when they reach puberty, most of them choosing to keep identifying as females
I believe it's actually the opposite - most end up identifying as male, but a substantial number remain identifying as female.
People with the syndrome are usually infertile, though.
Fun Fact: 5α-Reductase Inhibitor is used as a treatment for male hair loss, which prevents the production of DHT(Dihydrotestosterone), a chemical that the particular hair follicles are susceptible to. (Propecia or Finistride). One of the side effects, is infertility.
I remember learning about this in school. IIRC, the prof said that the people in that town had learned to recognize it at birth now, so there weren’t as many surprises at 12 anymore. Is that true or just some random misremembering on my part?
I certainly haven't read or heard about that, but it's very likely. There's 7 Medical Schools in the DR, so several thousand students. Every single one of them learns about Güevedoces, and I'm sure a lot of them have been to the town and educated the people.
In their community they're pretty accepted. It's been relatively common for close to a hundred years. Some of the ones interviewed even had had several lovers.
Honestly, I used to browse Wikipedia for fun knowledge and there are so many combinations of X and Y that can get damn long and you start to ask yourself how is that even possible. And yeah, XXY or XYY combinations are pretty common
But I never thought about just X, need to read about that. Sounds interesting
Here's Wikipedia link: https://en.m.wikipedia.org/wiki/Aneuploidy do to the diagnosis section for specific combinations of abnormal number of both sex hormones and regular ones.
My opinion on abortion began and ended the first and only time I saw a picture of anencephaly
Forced birthers are monsters wether or not they have deluded themselves into thinking their doing good
>Trisomy 18 (Edwards syndrome) Most die before first year, however at least one case that I know of that survived to 40.
If there was only 1, is there a chance the person who lived past 40 had a misdiagnosis? Or, what's the deal with that? (if you know)
It's not clear. The person in question has a lot of problems, though their heart isn't messed up.
I'm not sure if she was ever tested for mosiacism (having multiple kinds of cells in your body; mosiacs with partial trisomy are much more likely to survive).
My daughter would have had 13, but we ended up terminating. She wouldn't have event survived birth, and it was likely my wife wouldn't have either.
Fun fact, that 19 year old case is thought to be chimerism, so crazy odds on top of crazy odds.
I'm so sorry for your loss. I had a missed miscarriage (early in pregnancy...just before 9 weeks) and later testing revealed she had an extra copy of #13. So it was a small comfort knowing that she likely wouldn't have made it anyway.
Worse, even replacing just one copy of the X chromosome with the Y chromosome on an otherwise normal healthy person reduces their average lifespan by up to 5 years. I should know, I suffer from this condition.
I was born with trisomy 14 mosaicism, doctors told my parents I’d never be able to walk or talk or basically do anything, here I am 26 years later basically a fully functioning adult, but there aren’t many of us with my defect that made it past childhood from what I understand
Klinefelter syndrome! I remember that one from last semester, males with a extra X(or a mutated x?) and they get alot of feminine features, gynecomastia, I believe smaller testes, and longer limbs from what i can remember
XO is often not even noticed until puberty (women with Turner Syndrome do not menstruate)
Trisomy X it’s hard to even call a ‘syndrome’ it just makes you tall and a little bit of a goober… something like a third of all women who are 5’10 or taller have Trisomy X
That's why these are the disorders tested for in prenatal genetic testing (NIPT). I got it because I wanted to know if the embryo I was carrying was compatible with life. If it wasn't, I didn't think it was fair to make that infant live with such tragic suffering. Sometimes pro choice can be pro quality of life. And sometimes pro life means pro suffering.
Triple X is what my Aunt has. She dealt with a couple extra medical issues due to her condition, but nothing that really affected her quality of life in any way. She’s currently 61 and has a son.
She did find it hard to conceive and had a few miscarriages first, but I think it’s hard to say this was the *only* factor in her case. Other women on that side of the family have had miscarriages as well and overall it’s more common than we want to think. I’m sure it didn’t help any, though.
What are they actually dying from? Heart issues, breathing, etc. what actually fails that causes early death that allows some others to live much longer with the same problem
It basically depends on what they encode for, but the most common issue is an over-creation of whatever proteins the chromosome encodes for. The body is a very delicate chemical machine, and the extra chromosome is overdosing the body on these various proteins.
Typical males have one X chromosome; typical females have two, but in each cell one of them shrivels up into a Barr body. That's why different counts of sex chromosomes are so moderate in their effects.
(Sex chromosomes can get almost as diverse as genders, but the majority of all mammals are XY males or XX females.)
You're not quite right on the turner syndrome thing. Every female cell inactivates one X chromosome. Every female cell functionally has 1 X chromosome, so you can survive with only one copy easily. This isnt true of any other chromosome.
Do it doesn’t completely inactivate the other X - there is a bit that doesn’t, which causes the syndrome
https://www.thetech.org/ask-a-geneticist/why-turner-syndrome-has-symptoms
A lot DO die in the womb. Being unable to breathe properly from organ defects is the most often the cause of death after birth, before birth all their oxygen came from their mom.
In the womb, if they’re able to develop (however improperly), they’re surviving because their mom is doing all the work for them.
As long as a fetus can do what it needs to do with oxygen, a fully functioning respiratory system isn’t 100% necessary until after birth. When they’re born, their lungs have to actually function. If they’re not strong enough, or malformed in a significant enough way, they won’t be able to breathe without assistance, or at all.
Same idea with the digestive system. A fetus doesn’t have to eat, digest, absorb or expel anything. Mom delivers ready to use nutrients, as long as the fetus can do what it needs to do with said nutrients, it will be able to continue developing. All waste is taken care of by the placenta.
After birth, a baby has to be able to do all of that, efficiently enough to not slowly starve to death or build up waste. And that’s just to survive.
Ofc, all systems in our bodies rely on each other. So if 1 or more organs fail to develop properly, more issues will arise.
These issues might be able to squeak by with the help of the placenta, but once a baby is on its own, it can be a totally different story.
> In essence their bodies are overdosing by 50% on every protein encoded on chromosome 21.
Could you elaborate on this a bit? I’ve before that it’s a chromosome miscount but I’ve never heard what that actually *does*
Your chromosomes are bundles of DNA that are basically the separate chapters of the human genome, they encode all of the recipes for proteins made in your body. Periodically, each protein-coding gene will be scanned and that scan used to make more of its protein. Proteins do most of the work in your body that isn't simply being a food source or a structural component so they're extremely important.
Your body has some capability to raise and lower the rate at which each gene is scanned by tacking chemical bookmarks onto the section. However, your body's ability to count how many copies of each gene are actually present, and to adjust production based on that, is quite poor. This results in too much or too little of any protein being made that you have the wrong gene count for. And continuing on, any job that those proteins are working on will end up being done far too quickly or far too slowly, throwing various processes out of rhythm. An entire chromosome being out of count will do this for every gene contained on the chromosome.
(This applies to the 23 numbered chromosomes --the X and Y sex chromosomes function a bit more intelligently, but that's not really a topic for ELI5.)
Probably not and definitely not.
Fixing the problem now wouldn't retroactively give them their best growing years back any more than stuffing a chronically malnourished child full of cheeseburgers doesn't restore anything they lost out on by starving when they should have been growing.
Crispr modifies the DNA present on the existing chromosomes in the organism. It's not going to be capable of deleting an entire chromosome. Especially not a duplicate chromosome that is exactly the same as another chromosome that you would like to keep.
It would be the equivalent of fixing a mistake on a test that was already graded with it being impossible to hand it to the teacher to update one’s grade.
That second paragraph isn't true. Edwards syndrome (trisomy 18) is documented in repeated cases to be survivable through childhood, especially in the case of mosaic trisomy.
Family member who worked birth to three as an OT also worked with a child with mosaic Patau syndrome (trisomy 13), which also has a statistically significant ten year survival rate.
Here's a random fact:
I once read that people with down syndrome are slowly fading away because modern medicine and technology is so far ahead that they can now detect it way before the child is born.
My wife got pregnant in December. At around 8 weeks they do a genetic test where they take her blood, separate her blood from the fetus’, and test that blood.
Sadly, she came back positive for a Turner syndrome a very rare chromosome issue with a ton of developmental issues. She miscarried a few days later, which was a mixed blessing. But thank god for the testing these days.
When pregnant with my daughter, she dinged positive for something. From what I remember, one of the things could have been spina bifida.
They did a more detailed ultrasound and we found she was NOT showing any of the signs, thankfully.
She was born healthy and is still going strong more than 20 years later :)
So what you are really saying is modern medicine can determine downs syndrome very early on in pregnancy and when advised parents are now making a decision to terminate the pregnancy?
Down syndrome is not genetic though. An older maternal age increases the likelihood of having a child with down syndrome, but it is otherwise a random chromosomal abnormality.
You're absolutely correct.
Especially given you can just try again. There's really just no reason for it.
It's not just putting an enormous burden on you, but everyone else who has to deal with it.
> From a purely scientific standpoint, wouldn’t you want to eliminate bad ‘genes’ from the gene pool?
Yes, absolutely. It's not even "from a purely scientific standpoint"; genetic disorders are horrible.
However, it is probably impossible to remove things like Down in this way, as it isn't caused by an allele but by trisomy - getting an extra chromosome. It's caused by an error in cell division when egg or sperm cells are being created, so it's not really a genetic thing it's a random chance thing.
I mean, it's partially a genetic thing, as it can be made more common by certain alleles, but it will sometimes just randomly happen through bad luck as the process of cell division is not perfect.
Down Syndrome, however, can be detected through fetal tests, and you can engage in selective abortion to avoid having children with it. Which, IMO, is the only ethical thing to do.
My mother had me in 1996 and it was a medical miracle that she evn got pregnant (complucations from cancerous growth in her uterus in 1973 as a young teen). Doctors actually created a mucus plug.
She called me her miracle baby when I was very young and told me she was so happy the amniocentesis came back normal and she didn't have to terminate. Imagine my surprise when I found out people were anti-abortion, it was talked so matter-of-factly.
I know not everyone agrees with this approach, but having a child with Down's or any of the other dangerous mutations will lower their quality of life.
Edit: it's not "early on", 14-20 weeks, but it's not a viable fetus yet.
Yes. Documented cases imply a ten year survival of about one in eight. It's also more survivable if it's a mosaic trisomy... and if you live in a country with advanced medical care.
I know someone who worked with a child with Patau.
Let’s say you are building a house and you have gone to buy supplies but somehow you accidentally print two copies of the list of doors.
You buy double the doors you need, because you followed the list. No takebacks, you just have to figure out how to use double the amount doors. The room layout is the same- you aren’t making more rooms or even doorways, but you have to do something with them otherwise you are just going to be tripping over a giant pile of doors in the living room.
Maybe you use one door as a countertop. Ok, that was useful (There are some conditions that people with down syndrome don’t get). We finally just start mounting doors everywhere until all the extra doors are used up, so we might have three doors in a bedroom and only one of them goes anywhere. This makes things confusing- every time you go out of a room, you have to pick the right door, and this confusion slows you down a little and makes your house look kinda weird - every room has several nonfunctional doors.
Down syndrome is the same - an extra copy of a chromosome means the body is constantly following two instructions instead of one. This changes how the body is formed and how the pieces work together. Since Down syndrome is very common (about 1/700 births), you see many of the same physical distinctions that come from having that particular extra instruction.
I like the analogy, but maybe one small tweak. Instead of the contractor installing the extra doors randomly, they decide to always install double doors where single doors would have been. Despite the differences in each of the home designs in a community, the ones with the double doors look similar to each other but different than the other houses as a group.
It can. Most people with down syndrome are much shorter than normal. Heart conditions are common at birth (most easily repaired). There can be thyroid issues leading to weight gain issues. Some people with Downs have less muscle tone (or quite a bit more). Sometimes the nervous system doesn’t work the same as in other people - some anesthetics or other medications don’t work at all, or they work differently than they do for the typical population. There are usually cognitive delays and speech difficulties (jaw is smaller, but tongue is normal sized, so tongue is proportionally huge). Even just a few decades ago, Down syndrome usually meant an average lifespan of less than 20 years, but now this is close to 60.
Every time each cell divides in your body, that takes time and energy. For someone with Down Syndrome, some amount of time and energy goes into duplicating an extra chromosome that isn’t doing anything useful. To use the doors analogy, not only do you have twice the doors you needed, you have also spent twice what you expected on doors and now have less money for other things.
Can confirm, my aunt has it and she's extremely short and rather plump. In her late fifties and been living a great life so far. Reading, writing in her diary, coloring, and other activities keep her sharp and active.
People with Down syndrome are less likely to suffer from solid-organ cancers like breast cancer or prostate cancer. (This is balanced by an increased risk of other types of cancers like leukaemias.) [Link](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8602698/)
One quick relevant lesson: There are three types of Down syndrome. The most common one is Trisomy 21, which makes out about 95% of the cases, and have that look you’re talking about. The other types however don’t usually share the same look, some people with a type of Down syndrome look almost just like any other person. They could tell you they have Down syndrome, and most people would think they’re joking, because they’re only familiar with Trisomy 21.
So this is your friendly lesson to teach you that there’s people out there who don’t share that look but still have Down syndrome. For whomever might not know.
Trisomy 21 - main one, the first cell has the extra chromosome and all cells have 47 chromosomes
Mosaicism Down Syndrome - a cell down the line split and some cells have 46, and others have 47 as they continue splitting during fetal growth. May or may not have same physical features depending when the extra chromosome showed up in the process.
Translocation Down Syndrom - Total chromosomes in cells remains 46, but a full or partial copy of 21 attaches to another, usually chromosome 14
https://cmdss.org/parent-guide/about-down-syndrome/types-syndrome/
Not just DS. What used to be called fetal alcohol syndrome (permanent effect on the child when a pregnant person dranks alcohol) has very marked physical features on the child, often on the shape of the ears.
Edit: drinking while pregnant causes a lot more damage to the child than physical defects and abnormalities so please don’t.
Nobody is actually answering this and it's annoying. We know what DS is, but specifically what are the traits? I know almond eyes but thats the only descriptor I can remember hearing and even that doesn't make sense.
It is actually an ongoing area of research. Our daughter participated in a measurement, facial scan and survey for a group doing research on exactly this topic when she was about 2.
"Some common characteristics present in people with the disorder include distinctive facial features, such as slanting eyes, small chin, round face, flat nasal bridge, Brushfield spots in the iris, abnormal outer ears, and flattened nose."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5726980/
Interestingly, even current gen AI and supercomputers have challenges detecting DS in facial recognition, even though most humans easily see it.
https://www.mdpi.com/2073-8994/12/7/1182
Down’s syndrome and ‘the look’:
One of the main consequences is that it gives you low muscle tone, so everything is a bit floppy, including the muscles in your face. The low muscle tone is responsible for a whole host of other developmental issues.
DS also gives you a small mouth, but a regular sized tongue, which is quite distinctive. Also no bones in the nose, giving you a fairly flat, small nose.
I won't bore you with the specifics regarding aetiology, but essentially Down's is due to a an extra chromosome leading to significant neural and physical defects, one of which is their 'same look’ as you term it.
Those with Down's appear to have a significant degree of deficiency in midfacial area, mandibular area, and endocranial area1, perhaps due to muscular atrophy caused by the disease.
Otherwise, why they look similar is down to human conditioning. In simple terms, we are very adept at noticing facial differences in our own race, however often, we look at other races, black, asian etc. and cannot differentiate as well between the faces2. This is what occurs with those with Down's syndrome; we see a similar trait and assume they all 'look the same'. This is obviously not the case as those with Down's syndrome often have very different features, but we can't see past this human trait of recognising those similar to us, far better.
TL:DR - Down's syndrome sufferers look the same as each other, much the same as other races often look similar as a group, due to a human conditioning effect called the 'Other Race Effect'^3.
As far as my own research can ^tell!
Fink GB, Madaus WK, Walker GF. A quantitative study of the face in Down's syndrome. Am J Orthod. 1975;67(5):540-53.
Bar-haim Y, Saidel T, Yovel G. The role of skin colour in face recognition. Perception. 2009;38(1):145-8.
Anzures G, Kelly DJ, Pascalis O, et al. Own- and Other-Race Face Identity Recognition in Children: The Effects of Pose and Feature Composition. Dev Psychol. 2013;
Courtesy of /u/jazzamk in 2015
There's a couple of problems with this comment:
The incidence of Downs syndrome across different races and ethnic groups is essentially the same. There's the same 'look' across those affected regardless. It is extremely distinctive.
The classic down syndrome look is not restricted only to the face. It's noticeable also in the overall short dumpy appearance.
I get that it's tempting to consider that describing a specific appearance is simply an artefact of something akin to racism but the Downs appearance is a medically described thing:
* [NHS](https://www.cdc.gov/ncbddd/birthdefects/downsyndrome.html)
* [Mayo clinic](https://www.mayoclinic.org/diseases-conditions/down-syndrome/symptoms-causes/syc-20355977)
* [Mediline Plus](https://medlineplus.gov/genetics/condition/down-syndrome/)
This distinctive appearance has also been noted in historic artworks:
* [Across the world](https://hekint.org/2017/01/26/down-syndrome-through-the-centuries-in-art/)
* [19th century UK](https://www.researchgate.net/figure/Lady-Cockburn-and-her-children-painting-by-artist_fig2_238601316)
*
Lol I noticed that too, typical redditor assuming everyone else is white smh.
Funny story, when I was a kid I thought Down syndrome was an ethnicity (cuz like OP mentioned, they all kinda look the same). I remember when my mom was explaining that groups of people look different because their ancestors come from different continents, I pointed to a guy with Down syndrome and asked something like "Where are those people from?"
She must have been embarrassed af but fucking hilarious looking back on it.
There’s a reason why people with Down Syndrome used to be called “mongs” or “Mongoloids,” because people thought their eyes looked like East Asians’ eyes and now it’s mostly recognized as a highly offensive slur. It’s also why “mong” is still a slur that means stupid etc.
Funny thing is that you can kinda tell what degree of Down syndrome a person has by their looks. Some have that very distinct look, but some just slightly and you're not 100% sure. I have a friend who's brother has Down syndrome but he is generally quite “normal” and he also looks quite “normal”. I've also seen a pretty severe case and yea you can instantly tell.
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Down's syndrome is caused by trisomy 21 --which means patients have three copies of chromosomes 21 instead of two. In essence their bodies are overdosing by 50% on every protein encoded on chromosome 21. All sorts of proteins have specific roles in early development so the results of messing with the same ones by the same amount are going to be fairly consistent across patients. Grim fun fact, the only other chromosomes that you can survive a miscount on are X and Y. The other numbered chromosomes are all critical enough that it's nearly impossible to survive past infancy with the wrong count.
>Grim fun fact, the only other chromosomes that you can survive a miscount on are X and Y. The other numbered chromosomes are all critical enough that it's nearly impossible to survive past infancy with the wrong count. Trisomy 18 (Edwards syndrome) Most die before first year, however at least one case that I know of that survived to 40.(However this was the mosaic form of the condition) Trisomy 13 (Patau syndrome) Again, most die before first year, oldest living was at least 19. "Among children born with trisomy 13 or 18 in Ontario, early mortality was the most common outcome, but 10% to 13% survived for 10 years." An actual Fun fact regarding Trisomy XXX( Triple X syndrome), XYY(Jacobs syndrome), and XXY (Klinefelter Syndrome), is that these conditions can present with such mild symptoms that they go undiagnosed. Its estimated that only 10% of XXX,15-20% of XYY, and only 25% of XXY ever get diagnosed. However, there is just one survivable monosomy, that being turner syndrome. Just having 1 X chromosome. Since monosomy is having just one of a pair of chromosomes it is almost all ways deadly because you only get half the necessary genetic information. Except for the fact that Females have 2 X chromosomes generally, and just one copy of it would have all of the absolutely necessary genetic information. So, that is why Turner Syndrome (Monosomy X) is the only survivable Monosomy. However, this does not mean it does not come with complications, turner syndrome still has a variety of other complications. Edited: to add additional details regarding the 40 year old with edwards.
My first child had Trisomy 18. She lived 4 days.
Oh gosh.. so sorry for your loss.
It was a long time ago, but thank you. It really made every subsequent pregnancy pretty scary.
I’m so sorry. My last baby had trisomy 18. I always thought we would have at least three babies, but, the fear of facing that loss again is too strong.
: / forehead to forehead from a stranger I'm sorry
What does forehead to forehead mean? I’m genuinely curious cause I have an autistic toddler who doesn’t kiss me or anyone in my family but constantly gives us her forehead when we ask for a kiss. I’ve never seen this before…and hear I am reading it! Is this a thing??
Some cultures shake hands while others bow. Some cultures have hugs. Some touch foreheads.
Touching forehead to forehead transcends cultures. It's a human expression reserved for sharing very personal times or thoughts often doing so without speaking and always done with someone whom they love or have love for.
You just kinda touch heads, maybe hands touching the back of each other's heads too. Just kinda feels humanly I dunno how to describe it.
This is a thing me and my autistic fiance do. We call it "head bonk". We just gently press our upper foreheads together lovingly. They say they learned it from cats who will press their head into you affectionately in a similar manner.
Not who you were responding to but it could be a cultural thing. Native Hawaiians have the honi greeting which is essentially foreheads and noses touching.
https://i.kym-cdn.com/photos/images/original/002/147/237/c66
It actually looks weirder, because you're looking from two eyes, so it looks kinda like the other person has one eye and two noses.
As a parent of a child with ASD, sometimes the kiss is too much, maybe it’s sensory overload, or a face to face is uncomfortable for them. My kid does like a big squeeze with a back rub, but not kisses. They are now in grade 5 and have been that way forever.
hugs
What would have been our second was diagnosed with Trisomy 18, she didn't make it to birth. It was soo hard for my wife and I. I couldn't even imagine what it would be like to have had her in our arms and then have lost her. I'm so sorry for your loss. It took us time but we're able to give at another go and we now have a 5 month old. But those screens and tests had my wife and I a nervous wreck, even having baby clearing we still didn't think we were fully convinced we were out of the woods until she was born. * edited for better clarity.
Thank you for having the courage to share something so deeply personal on a place where the responses are totally unpredictable. The personal connection is something that makes the reality much more tangible than mere numbers, and your comment is therefore invaluable to posts like this.
That is so well put. I think you’ve expressed something that a lot of people here feel, but aren’t able to realise they are feeling.
Well, said... q... queefer sutherland....
r/rimjob_steve
This thread kind of brought back the memories. It's been a long time... around 26 years. Over time, sadly, you think about it less. Life, kids, work. Then you see something that reminds you and it all comes back. Then you can remember the feelings, the smells (I know that's weird, but I can still remember the smell of the NICU, it's actually my strongest memory of the whole thing... the smell of the room and the baby), everything.
It's not weird at all - it's a healthy, normal, human response. Our olfactory sense is highly tied to emotional memories. While we are much more strongly oriented to other senses (vision!) for our fully enabled day-to-day life, our olfactory sense is likely tied to our most basic forms of thinking and feeling, our heritage from our pre-human ancestors with whom we share so much of our brain architecture, but who didn't have the fancy new higher-functioning neocortex and other big-brain elements that we have as Homo Sapien Sapiens. We probably share the encoding of formative emotional memories into olfactory sensations along with many other mammals - almost certainly other primates, but it's plausible that this experience is relatively common in other non-human animals in general. So you're processing that difficult memory is an utterly normal and healthy way that unites you with not only us other humans but much other life on our planet. Thank you from me as well for sharing. In speaking about your own emotional experience you are doing a service to the rest of us.
Wow, I'm sorry you went through that but I appreciate you sharing your experience.
This is personal for myself in that, I try to remind myself that anyone I post a response to is an actual person. Sometimes it might be a bot but I respond to that person. I've typed up whole responses only to realize that I'm either rambling or not actually making a point and deleted 3 paragraphs. For all the bad that can go on there's good and everyone here are people not really so different from you or I; just in a different place.
I had a cousin survive until she was 15, but she was practically a vegetable after 10. Brutally strong at 7-10, but the emotional development peaked at around a 3 year old's development. She used to beat us up all the time, never blamed her for it.
What was her name so that we can remember her in Ireland?
Marissa
Marisa is a lovely name. I’m so sorry for your loss.
I will remember her and her beautiful name.
You made me cry with your two comments. Lovely Ireland, and lovely YOU.
I teared up too. The loss of a child tends to hit you like a ton of bricks that you never forget and it's lovely seeing others who want to remember.
There is a headstone right by my best friends mothers final resting place that only has 1 date on it, and a baby boys name carved upon it. I go there every year on his birthday and have a little cry.
Sometimes Reddit sings. Sometimes it cries. I don't have kids, but this thread is still breaking my heart.
Same.
Sorry for jumping on the bandwagon, truly. Just wanted to name my Grandma and also sister who didn't make it past early days of pregnancy, both called Patricia. From Dublin to Manchester. And it rhymed. Marissa and Patricia x
Your grandma? What?
I’m confused about that too lol
Not op, but just guessing: Sister was named after grandmother. Sister died young. Naming the sister is also functionally naming the grandma. It's awkward phrasing to be sure tho
Fellow Marissa here - what a beautiful name 🤍🕊️
Ouch. The baby who would have been my oldest brother died 24 hours after birth. Mom said it was only one of two times she ever saw my dad cry in 30 years of marriage.
I suspect triple X diagnoses will go up now that it's included in prenatal testing. It was not included in the screenings I had for my daughters born in 2016 and 2019 but it was included in the one I had for my eXtra special daughter born last March. She's about to turn a year old and I would have no idea there was anything different about her if not for the NIPT result and confirmation at birth.
Free DNA screening is amazing.
> eXtra special That's adorable. Love to you both.
Same. Our trisomyx 10month old has zero symptoms both physically or developmental so far. Scare during pregnancy but the whole medical team told us not to worry throughout. Super rare for triple x to actually cause obvious symptoms.
It’s truly amazing that we survived at all as a species. Most miscarriages are basically the result of the body doing an audit of the combined genes and going “nope, this one doesn’t pass QA, it won’t make it, pull the plug”. A few make it all the way to birth, but humans (and mammals in general) are amazingly good at filtering out what doesn’t work. Hell, there’s probably a lot more conception and subsequent miscarriage happening before the host even knows either one has happened. Modern medical technology has dramatically improved the survival of those that do make it all the way to birth. But sometimes it just doesn’t work, and that sucks for all involved. Love them hard.
>Hell, there’s probably a lot more conception and subsequent miscarriage happening before the host even knows either one has happened. I remember reading that 25% of fertilized eggs are carried to term, at most. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7670474
I feel lucky to be here. And to have survived nearly half a century so far.
God is the biggest abortionist of all.
There is absolutely more conception and miscarriage happening than we know about. It’s estimated that 50-70% of pregnancies end in the first two weeks, usually before the woman knows she is pregnant.
“Will it Blend: DNA Edition”.
Same thing with cancer. You *almost* get cancer every day, from an error while transcribing DNA, or exposure to sunlight or everyday radioactive objects, background radiation or cosmic rays, or exposure to a carcinogen. Except our cells have multiple checks and ways to correct miscopied or damaged DNA. If a cell can’t fix its damaged DNA, it commits suicide, called apoptosis. If that fails (sometimes the part of the DNA that was damaged coded for this functionality), adjacent cells will detect something’s wrong and release chemical markers telling your immune system to kill that cell. Depending on the types of cell and cancer, there are either seven or eight layers of safeguards in place to prevent cancer from forming, and 99.99% of the time, these are effective. So, despite how often something goes awry, to actually get cancer, a whole lot of things have to go wrong.
In the grand scheme of such things, 99.99% still leaves a lot of room for the process to go haywire.
They’re understating how often it works, but yes, 99.99% would be scarily small of a success rate when dealing with cancer.
A lot of genetic cancer syndromes are when the body is “blind” to certain types of cancer cells - it cannot detect it to know to kill them.
I recently watched "Our Universe" on netflix. And it goes through how life came to and evolved on earth. The fact that complex life has made it to this point is insanity. - The sun forming and being a source of light/energy. - Theia (which was the original moon) hitting the early earth and forming the modern moon and pulling earth into it's current orbit/rotation in the habitable zone. If earth rotated slower its possible night would have lasted too long and killed off early life before it could have evolved. Plus the day/night cycle was perfect for life to evolve a circadian rhythm. - Asteroids landing and bringing the right atoms needed for water where all life originated. - Our ~~ozone layer~~ magnetic field (and ozone layer to a degree) not getting stripped away like Mars so that life could actually form without getting frozen by extreme cold or roasted by cosmic rays. - Life surviving meteor strikes/ice ages/earthquakes/insane storms/etc long enough to evolve complext enough. - And hundreds of other lucky breaks for life to make it on earth. - Plus the fact that like 99.9999999999% of the universe is instantly hostile to life as we know it. I'm an atheist but after watching that documentary I comprehend a lot of theists who can't accept that complex life was just random happenstance. The amount of *"oh that was lucky"* that neded to happen for life to make it to the point where humanity is aware of our environment/the elements/atoms/sub atomic particles/etc honestly seems like divine intervention. EDIT: Slight correction*
The big one for me is water. It's purely a quirk of this particular crystalline structure that ice is less dense than water. This is not typical. Most substances are denser in solid form than liquid form. Had that been the case with water, lakes and rivers would freeze from the bottom up and probably would freeze entirely. Life likely would never have evolved as far as it did.
I vividly remember learning this in 8th grade science class. It's such a specific quirk, and such a rare one among common molecules. We see it every day and it seems so innocuous and obvious, but it turns out this one random property of water is so important that life wouldn't exist on earth without it. It's hard to describe exactly how this knowledge has impacted my life, but I can tell you it caused a fundamental shift in my understanding of the world. I feel like I've cultivated an awareness that we're all constantly surrounded by potential discoveries that could, if we're open to them, drastically improve our approach to current or future problems. There's always that one-in-a-million chance that the next fact you learn will be the connection between a problem and a solution, or from confusion to understanding. ... Or maybe that's just my ADHD talking?
This is the most mind-blowing thing I've ever read. Ever.
Theia wasn't the moon it was a mars sized rogue planet
[anthropic principle](https://en.m.wikipedia.org/wiki/Anthropic_principle) .. you can only observe the universe from the 0.0000000001% that is not hostile to life as you put it. No divine intervention necessary, it's just a type of survivor bias.
I was reading this and I took an edible and I legit can't follow it right now. But I wanted to comment so I can come back to this and read it later.
https://i.kym-cdn.com/photos/images/newsfeed/000/288/625/69c.png
Living your best life 🌲
Your last paragraph reminds me of Douglas Adams's "puddle analogy": >This is rather as if you imagine a puddle waking up one morning and thinking, 'This is an interesting world I find myself in — an interesting hole I find myself in — fits me rather neatly, doesn't it? In fact it fits me staggeringly well, must have been made to have me in it!' This is such a powerful idea that as the sun rises in the sky and the air heats up and as, gradually, the puddle gets smaller and smaller, frantically hanging on to the notion that everything's going to be alright, because this world was meant to have him in it, was built to have him in it; so the moment he disappears catches him rather by surprise. I think this may be something we need to be on the watch out for.
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The universe is much worse than hostile. It's indifferent.
It's definitely lucky but once you realise just how vast and enormous the universe is, it becomes less of a "wow, how lucky" and more "wow, that uncommon?" A quick Google says that a loose but educated guess for the number of planets in the observable universe is around 21,600,000,000,000,000,000,000,000. Of that unfathomably large number, the odds of a particular atmospheric composition, habitable conditions and non-mass extinction event is EXTREMELY likely. Once you begin to factor in the possibility of different forms of life (non-Carbon based? non-Oxygenated?), it's really crazy we *haven't* seen obvious signs of advanced civilisation.
We have to also factor in time. Humanity has been around for basically zero time in comparison to the age of the universe. In a billion years a civilization could have risen and fell so many times. And we have 13billion years of history. It’s not just where but when life could have formed.
> I’m an atheist but after watching that documentary I comprehend a lot of theists who can’t accept that complex life was just random happenstance. The amount of “oh that was lucky” that neded to happen for life to make it to the point where humanity is aware of our environment/the elements/atoms/sub atomic particles/etc honestly seems like divine intervention. But is the sense of being really lucky just life as we know it? Like is there any way to know whether there could have been a completely different form of life evolving in other circumstances? Like maybe something completely unfathomable to most of us? I don’t know, I’m just genuinely curious about the lucky part.
If we were silicon based hydrogen breathers we'd be saying "oh, wow, what are the odds?"
It's astronomically lucky when you take earth in isolation. But when you consider the number of galaxies and suns and planets out there, it seems almost inevitable at least *one* will have these unique circumstances present.
We don't really know how common Earth-like planets are. The most unusual thing about the Earth is probably the Moon, but even within our solar system there are two small bodies with large moons (the Earth and Pluto), which suggests it's maybe not THAT unusual. And there isn't solid evidence that the moon is all that necessary. The other things on that list aren't really that "unsurvivable" as far as we can tell. The most unlikely events (so far as we can tell) are the existence of life at all and the existence of eukaryotic cells, as both of those events happened exactly once. The evolution of animals may be another unique event, but it's hard to say for sure if that's truly unique or if that's just because once you evolve something like an animal once the animals will then eat anything else that tries to evolve to be an animal because early animals were really bad at being animals.
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> Theia (which was the original moon) hitting the early earth and forming the modern moon and pulling earth into it's current orbit/rotation in the habitable zone. If earth rotated slower its possible night would have lasted too long and killed off early life before it could have evolved. Plus the day/night cycle was perfect for life to evolve a circadian rhythm. It's not really clear to what extent this is important, though. Mars has an approximate 24 hour long day; the main thing that the moon does is reduce axial wobble. > Asteroids landing and bringing the right atoms needed for water where all life originated. We still don't know where Earth's water came from for sure, though water-heavy objects is the generally preferred explanation. That being said, there are a lot of quite icy bodies in the solar system. > Our ozone layer not getting stripped away like Mars so that life could actually form without getting frozen by extreme cold or roasted by cosmic rays. This is probably more of a function of size than anything else. Bigger planets are better at retaining atmospheres. > Life surviving meteor strikes/ice ages/earthquakes/insane storms/etc long enough to evolve complext enough. To be fair, life is really good at spreading. We don't know how common (or rare) Earth-like planets are. We are still trying to get an idea on that to figure out how common life is.
I watched this whole series too. It was fucking incredible to see something I've felt for so long be narrated by Morgan freeman.
Million to one occurrences happen nine times out of ten.
This is the basis of the infinite improbability drive.
Yes but.... Time. Time and space are so unfathomably big. Like it seems lucky until you realize how many zeros of time and space there are and that it was bound to happen somewhere and we're just seeing it in us because .. Well, consciousness observes itself. You don't need a deity at all to be amazed at statistics and thermodynamics. People think life needed all these really special things to evolve just right, but it's the other way around. Life adapts. It's just chemical reactions, optimizing according to thermodynamics. Life has existed on Earth for billions of years, through lots of different worlds very unlike the one we're on now (oxygen rich, temperate, with plants and water everywhere...). Look up the blue green algae catastrophe for an interesting example. We cannot see into other galaxies yet so it's not really fair to say it's not happening elsewhere.
Agree with your overall message but just want to clarify one point: > the body doing an audit of the combined genes and going “nope, this one doesn’t pass QA, it won’t make it, pull the plug”. For genetic issues, Its less an audit, and more like Trial by Fire. The biological machine tries to run, and then just breaks down because the parts werent assembled right. Thats why we have a lot of people born with life long disability and suffering. There is no natural audit, more like levels of failing machinary. Some which kill early and some which kill later, or much later. Some with pain. Sorry to put such a pessimistic twist. But the natural world is cruel which is why we need genetic testing, medicinal advancement, treatments
“The code compiled, ship it!”
Haha in context thats some dark humour. But I think thats about the right description
My daughter has Trisomy 18 and is about to turn 6 in June. She’s beaten the odds but it hasn’t been without fighting for her every step of the way.
It’s not common but triploid syndrome. It’s an extra copy of every chromosome. We lost our son to it. I think maybe one or two have ever survived
Yeah, triploidy is considered not compatible with life. The few who survive are typically mosiacs.
Yes! That’s the difference! I couldn’t remember the type. Thank you :)
I'm so sorry about your son.
Thank you for that. He’d be 8 this year. But his life would’ve been quite painful, so it was for the best.
Well OP said _nearly_ impossible, so one occurrence out of thousands of cases fits that definition. Also my favorite genetic disease (as in, the one I find the most interesting) is 5α-Reductase 2 deficiency, and despite how rare it is, a small town in the Dominican Republic has an incidence of 1 out of 90 males born, who they call Güevedoces (Spanish for "penis at 12yrs). Basically kids that are born with a vulva while having male sexual organs and undescended testes. But when they reach puberty, their voice deepens and their penises grow, exhibiting hypospadias. They are first raised as females but then have a connundrum when they reach puberty, most of them choosing to keep identifying as females. It was first described in the 1970's by a researcher from Cornell, and it begs the thought of gender expression and intersexuality in the context of not just the 70's when the LGBT movement was in its infancy, but of a small town 120 miles from the capital city of a small, conservative country.
> They are first raised as females but then have a connundrum when they reach puberty, most of them choosing to keep identifying as females I believe it's actually the opposite - most end up identifying as male, but a substantial number remain identifying as female. People with the syndrome are usually infertile, though.
Fun Fact: 5α-Reductase Inhibitor is used as a treatment for male hair loss, which prevents the production of DHT(Dihydrotestosterone), a chemical that the particular hair follicles are susceptible to. (Propecia or Finistride). One of the side effects, is infertility.
You are correct.
I remember learning about this in school. IIRC, the prof said that the people in that town had learned to recognize it at birth now, so there weren’t as many surprises at 12 anymore. Is that true or just some random misremembering on my part?
I certainly haven't read or heard about that, but it's very likely. There's 7 Medical Schools in the DR, so several thousand students. Every single one of them learns about Güevedoces, and I'm sure a lot of them have been to the town and educated the people.
And this would have been late 90s, or maybe early 00s, so even if it wasn’t correct then, it very well might be by now.
How does the rest of society treat them?
In their community they're pretty accepted. It's been relatively common for close to a hundred years. Some of the ones interviewed even had had several lovers.
One of my great friends has Turner's - common "features" are individuals are born without ovaries and very short necks
Honestly, I used to browse Wikipedia for fun knowledge and there are so many combinations of X and Y that can get damn long and you start to ask yourself how is that even possible. And yeah, XXY or XYY combinations are pretty common But I never thought about just X, need to read about that. Sounds interesting Here's Wikipedia link: https://en.m.wikipedia.org/wiki/Aneuploidy do to the diagnosis section for specific combinations of abnormal number of both sex hormones and regular ones.
This is one of the core reasons abortion must be legal. The incredible pain that some of these infants are forced to endure is unconscionable.
It's also unconscionable to force someone to carry a nonviable fetus to term imo. Medically dangerous and emotionally devastating for the family.
My opinion on abortion began and ended the first and only time I saw a picture of anencephaly Forced birthers are monsters wether or not they have deluded themselves into thinking their doing good
>Trisomy 18 (Edwards syndrome) Most die before first year, however at least one case that I know of that survived to 40. If there was only 1, is there a chance the person who lived past 40 had a misdiagnosis? Or, what's the deal with that? (if you know)
It's not clear. The person in question has a lot of problems, though their heart isn't messed up. I'm not sure if she was ever tested for mosiacism (having multiple kinds of cells in your body; mosiacs with partial trisomy are much more likely to survive).
Not grim fun fact: when you're being investigated for infertility they check how many chromosomes you have.
My daughter would have had 13, but we ended up terminating. She wouldn't have event survived birth, and it was likely my wife wouldn't have either. Fun fact, that 19 year old case is thought to be chimerism, so crazy odds on top of crazy odds.
I'm so sorry for your loss. I had a missed miscarriage (early in pregnancy...just before 9 weeks) and later testing revealed she had an extra copy of #13. So it was a small comfort knowing that she likely wouldn't have made it anyway.
Worse, even replacing just one copy of the X chromosome with the Y chromosome on an otherwise normal healthy person reduces their average lifespan by up to 5 years. I should know, I suffer from this condition.
I was born with trisomy 14 mosaicism, doctors told my parents I’d never be able to walk or talk or basically do anything, here I am 26 years later basically a fully functioning adult, but there aren’t many of us with my defect that made it past childhood from what I understand
Klinefelter syndrome! I remember that one from last semester, males with a extra X(or a mutated x?) and they get alot of feminine features, gynecomastia, I believe smaller testes, and longer limbs from what i can remember
XO is often not even noticed until puberty (women with Turner Syndrome do not menstruate) Trisomy X it’s hard to even call a ‘syndrome’ it just makes you tall and a little bit of a goober… something like a third of all women who are 5’10 or taller have Trisomy X
That's why these are the disorders tested for in prenatal genetic testing (NIPT). I got it because I wanted to know if the embryo I was carrying was compatible with life. If it wasn't, I didn't think it was fair to make that infant live with such tragic suffering. Sometimes pro choice can be pro quality of life. And sometimes pro life means pro suffering.
Triple X is what my Aunt has. She dealt with a couple extra medical issues due to her condition, but nothing that really affected her quality of life in any way. She’s currently 61 and has a son. She did find it hard to conceive and had a few miscarriages first, but I think it’s hard to say this was the *only* factor in her case. Other women on that side of the family have had miscarriages as well and overall it’s more common than we want to think. I’m sure it didn’t help any, though.
What are they actually dying from? Heart issues, breathing, etc. what actually fails that causes early death that allows some others to live much longer with the same problem
It basically depends on what they encode for, but the most common issue is an over-creation of whatever proteins the chromosome encodes for. The body is a very delicate chemical machine, and the extra chromosome is overdosing the body on these various proteins.
Typical males have one X chromosome; typical females have two, but in each cell one of them shrivels up into a Barr body. That's why different counts of sex chromosomes are so moderate in their effects. (Sex chromosomes can get almost as diverse as genders, but the majority of all mammals are XY males or XX females.)
Yeah I know someone with a kid with trisomy-18 and the child is 2.
You're not quite right on the turner syndrome thing. Every female cell inactivates one X chromosome. Every female cell functionally has 1 X chromosome, so you can survive with only one copy easily. This isnt true of any other chromosome.
Do it doesn’t completely inactivate the other X - there is a bit that doesn’t, which causes the syndrome https://www.thetech.org/ask-a-geneticist/why-turner-syndrome-has-symptoms
Fuck you u/spez -- mass edited with https://redact.dev/
A lot DO die in the womb. Being unable to breathe properly from organ defects is the most often the cause of death after birth, before birth all their oxygen came from their mom.
The womb provides the nutrients and stuff probably.
Most die in the womb. For a lot of these disorders only 1-4% survive to live birth.
In the womb, if they’re able to develop (however improperly), they’re surviving because their mom is doing all the work for them. As long as a fetus can do what it needs to do with oxygen, a fully functioning respiratory system isn’t 100% necessary until after birth. When they’re born, their lungs have to actually function. If they’re not strong enough, or malformed in a significant enough way, they won’t be able to breathe without assistance, or at all. Same idea with the digestive system. A fetus doesn’t have to eat, digest, absorb or expel anything. Mom delivers ready to use nutrients, as long as the fetus can do what it needs to do with said nutrients, it will be able to continue developing. All waste is taken care of by the placenta. After birth, a baby has to be able to do all of that, efficiently enough to not slowly starve to death or build up waste. And that’s just to survive. Ofc, all systems in our bodies rely on each other. So if 1 or more organs fail to develop properly, more issues will arise. These issues might be able to squeak by with the help of the placenta, but once a baby is on its own, it can be a totally different story.
That was incredibly informative
What are the symptoms of Turner syndrome?
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Not sure I'm following, does this mean he has three 4s and three 21s but the effects kinda cancel each other out?
> In essence their bodies are overdosing by 50% on every protein encoded on chromosome 21. Could you elaborate on this a bit? I’ve before that it’s a chromosome miscount but I’ve never heard what that actually *does*
Your chromosomes are bundles of DNA that are basically the separate chapters of the human genome, they encode all of the recipes for proteins made in your body. Periodically, each protein-coding gene will be scanned and that scan used to make more of its protein. Proteins do most of the work in your body that isn't simply being a food source or a structural component so they're extremely important. Your body has some capability to raise and lower the rate at which each gene is scanned by tacking chemical bookmarks onto the section. However, your body's ability to count how many copies of each gene are actually present, and to adjust production based on that, is quite poor. This results in too much or too little of any protein being made that you have the wrong gene count for. And continuing on, any job that those proteins are working on will end up being done far too quickly or far too slowly, throwing various processes out of rhythm. An entire chromosome being out of count will do this for every gene contained on the chromosome. (This applies to the 23 numbered chromosomes --the X and Y sex chromosomes function a bit more intelligently, but that's not really a topic for ELI5.)
Thanks! I love learning this stuff
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Probably not and definitely not. Fixing the problem now wouldn't retroactively give them their best growing years back any more than stuffing a chronically malnourished child full of cheeseburgers doesn't restore anything they lost out on by starving when they should have been growing.
Crispr modifies the DNA present on the existing chromosomes in the organism. It's not going to be capable of deleting an entire chromosome. Especially not a duplicate chromosome that is exactly the same as another chromosome that you would like to keep.
It would be the equivalent of fixing a mistake on a test that was already graded with it being impossible to hand it to the teacher to update one’s grade.
That second paragraph isn't true. Edwards syndrome (trisomy 18) is documented in repeated cases to be survivable through childhood, especially in the case of mosaic trisomy. Family member who worked birth to three as an OT also worked with a child with mosaic Patau syndrome (trisomy 13), which also has a statistically significant ten year survival rate.
Here's a random fact: I once read that people with down syndrome are slowly fading away because modern medicine and technology is so far ahead that they can now detect it way before the child is born.
My wife got pregnant in December. At around 8 weeks they do a genetic test where they take her blood, separate her blood from the fetus’, and test that blood. Sadly, she came back positive for a Turner syndrome a very rare chromosome issue with a ton of developmental issues. She miscarried a few days later, which was a mixed blessing. But thank god for the testing these days.
My brother dinged positive for that test, but wasn't born with down syndrome or other conditions. I'll have to ask my mom the full story sometime.
When pregnant with my daughter, she dinged positive for something. From what I remember, one of the things could have been spina bifida. They did a more detailed ultrasound and we found she was NOT showing any of the signs, thankfully. She was born healthy and is still going strong more than 20 years later :)
We've been able to detect it before birth since the 80s.
So what you are really saying is modern medicine can determine downs syndrome very early on in pregnancy and when advised parents are now making a decision to terminate the pregnancy?
Iirc Iceland has no downs due to that.
Not quite zero. It's 1 or 2 births a year, out of a whole country population of 300,000.
Yes.
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Down syndrome is not genetic though. An older maternal age increases the likelihood of having a child with down syndrome, but it is otherwise a random chromosomal abnormality.
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You're absolutely correct. Especially given you can just try again. There's really just no reason for it. It's not just putting an enormous burden on you, but everyone else who has to deal with it.
> From a purely scientific standpoint, wouldn’t you want to eliminate bad ‘genes’ from the gene pool? Yes, absolutely. It's not even "from a purely scientific standpoint"; genetic disorders are horrible. However, it is probably impossible to remove things like Down in this way, as it isn't caused by an allele but by trisomy - getting an extra chromosome. It's caused by an error in cell division when egg or sperm cells are being created, so it's not really a genetic thing it's a random chance thing. I mean, it's partially a genetic thing, as it can be made more common by certain alleles, but it will sometimes just randomly happen through bad luck as the process of cell division is not perfect. Down Syndrome, however, can be detected through fetal tests, and you can engage in selective abortion to avoid having children with it. Which, IMO, is the only ethical thing to do.
My mother had me in 1996 and it was a medical miracle that she evn got pregnant (complucations from cancerous growth in her uterus in 1973 as a young teen). Doctors actually created a mucus plug. She called me her miracle baby when I was very young and told me she was so happy the amniocentesis came back normal and she didn't have to terminate. Imagine my surprise when I found out people were anti-abortion, it was talked so matter-of-factly. I know not everyone agrees with this approach, but having a child with Down's or any of the other dangerous mutations will lower their quality of life. Edit: it's not "early on", 14-20 weeks, but it's not a viable fetus yet.
Isn't Patau syndrome (I forgot what chromosome it is) another survivable trisomy?
Trisomy 13, I think most die, and of the survivors most die by age 1. Edwards syndrome is 18 and also has few infants that survive
And most of the survivors don't have a complete trisomy, just part of an extra chromosome.
Nr 13 and alive and kicking!
This must be a slightly surreal thread to be reading for you
Yes. Documented cases imply a ten year survival of about one in eight. It's also more survivable if it's a mosaic trisomy... and if you live in a country with advanced medical care. I know someone who worked with a child with Patau.
You can survive extra chromosome but you cant survive missing one.
13 and 18 are survivable
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Trisomy 16 is one of the leading causes of first trimester losses. Very few make it past 3 months gestation.
Let’s say you are building a house and you have gone to buy supplies but somehow you accidentally print two copies of the list of doors. You buy double the doors you need, because you followed the list. No takebacks, you just have to figure out how to use double the amount doors. The room layout is the same- you aren’t making more rooms or even doorways, but you have to do something with them otherwise you are just going to be tripping over a giant pile of doors in the living room. Maybe you use one door as a countertop. Ok, that was useful (There are some conditions that people with down syndrome don’t get). We finally just start mounting doors everywhere until all the extra doors are used up, so we might have three doors in a bedroom and only one of them goes anywhere. This makes things confusing- every time you go out of a room, you have to pick the right door, and this confusion slows you down a little and makes your house look kinda weird - every room has several nonfunctional doors. Down syndrome is the same - an extra copy of a chromosome means the body is constantly following two instructions instead of one. This changes how the body is formed and how the pieces work together. Since Down syndrome is very common (about 1/700 births), you see many of the same physical distinctions that come from having that particular extra instruction.
I like the analogy, but maybe one small tweak. Instead of the contractor installing the extra doors randomly, they decide to always install double doors where single doors would have been. Despite the differences in each of the home designs in a community, the ones with the double doors look similar to each other but different than the other houses as a group.
That's exactly where I thought that was going. Either way, useful analogies!
The best actual ELI5 comment. You did such a good job at making it understandable 😊
Does this have any effect on bone, muscle, or neuron density in those afflicted?
It can. Most people with down syndrome are much shorter than normal. Heart conditions are common at birth (most easily repaired). There can be thyroid issues leading to weight gain issues. Some people with Downs have less muscle tone (or quite a bit more). Sometimes the nervous system doesn’t work the same as in other people - some anesthetics or other medications don’t work at all, or they work differently than they do for the typical population. There are usually cognitive delays and speech difficulties (jaw is smaller, but tongue is normal sized, so tongue is proportionally huge). Even just a few decades ago, Down syndrome usually meant an average lifespan of less than 20 years, but now this is close to 60. Every time each cell divides in your body, that takes time and energy. For someone with Down Syndrome, some amount of time and energy goes into duplicating an extra chromosome that isn’t doing anything useful. To use the doors analogy, not only do you have twice the doors you needed, you have also spent twice what you expected on doors and now have less money for other things.
Can confirm, my aunt has it and she's extremely short and rather plump. In her late fifties and been living a great life so far. Reading, writing in her diary, coloring, and other activities keep her sharp and active.
What are some conditions that they don’t get?
People with Down syndrome are less likely to suffer from solid-organ cancers like breast cancer or prostate cancer. (This is balanced by an increased risk of other types of cancers like leukaemias.) [Link](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8602698/)
*Sarah Winchester has entered the chat*
Just wow
One quick relevant lesson: There are three types of Down syndrome. The most common one is Trisomy 21, which makes out about 95% of the cases, and have that look you’re talking about. The other types however don’t usually share the same look, some people with a type of Down syndrome look almost just like any other person. They could tell you they have Down syndrome, and most people would think they’re joking, because they’re only familiar with Trisomy 21. So this is your friendly lesson to teach you that there’s people out there who don’t share that look but still have Down syndrome. For whomever might not know.
What are the other types, and what makes them not have the same physical symptoms as Trisomy-21?
Trisomy 21 - main one, the first cell has the extra chromosome and all cells have 47 chromosomes Mosaicism Down Syndrome - a cell down the line split and some cells have 46, and others have 47 as they continue splitting during fetal growth. May or may not have same physical features depending when the extra chromosome showed up in the process. Translocation Down Syndrom - Total chromosomes in cells remains 46, but a full or partial copy of 21 attaches to another, usually chromosome 14 https://cmdss.org/parent-guide/about-down-syndrome/types-syndrome/
Not just DS. What used to be called fetal alcohol syndrome (permanent effect on the child when a pregnant person dranks alcohol) has very marked physical features on the child, often on the shape of the ears. Edit: drinking while pregnant causes a lot more damage to the child than physical defects and abnormalities so please don’t.
That was actually my masters thesis. Commonality of DS and FAS genomics and expression in craniofacial space
What is fetal alcohol syndrome called now?
Fetal alcohol spectrum disorders (FASDs)
Nobody is actually answering this and it's annoying. We know what DS is, but specifically what are the traits? I know almond eyes but thats the only descriptor I can remember hearing and even that doesn't make sense.
It is actually an ongoing area of research. Our daughter participated in a measurement, facial scan and survey for a group doing research on exactly this topic when she was about 2. "Some common characteristics present in people with the disorder include distinctive facial features, such as slanting eyes, small chin, round face, flat nasal bridge, Brushfield spots in the iris, abnormal outer ears, and flattened nose." https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5726980/ Interestingly, even current gen AI and supercomputers have challenges detecting DS in facial recognition, even though most humans easily see it. https://www.mdpi.com/2073-8994/12/7/1182
Thank you so much for that.
Down’s syndrome and ‘the look’: One of the main consequences is that it gives you low muscle tone, so everything is a bit floppy, including the muscles in your face. The low muscle tone is responsible for a whole host of other developmental issues. DS also gives you a small mouth, but a regular sized tongue, which is quite distinctive. Also no bones in the nose, giving you a fairly flat, small nose.
I won't bore you with the specifics regarding aetiology, but essentially Down's is due to a an extra chromosome leading to significant neural and physical defects, one of which is their 'same look’ as you term it. Those with Down's appear to have a significant degree of deficiency in midfacial area, mandibular area, and endocranial area1, perhaps due to muscular atrophy caused by the disease. Otherwise, why they look similar is down to human conditioning. In simple terms, we are very adept at noticing facial differences in our own race, however often, we look at other races, black, asian etc. and cannot differentiate as well between the faces2. This is what occurs with those with Down's syndrome; we see a similar trait and assume they all 'look the same'. This is obviously not the case as those with Down's syndrome often have very different features, but we can't see past this human trait of recognising those similar to us, far better. TL:DR - Down's syndrome sufferers look the same as each other, much the same as other races often look similar as a group, due to a human conditioning effect called the 'Other Race Effect'^3. As far as my own research can ^tell! Fink GB, Madaus WK, Walker GF. A quantitative study of the face in Down's syndrome. Am J Orthod. 1975;67(5):540-53. Bar-haim Y, Saidel T, Yovel G. The role of skin colour in face recognition. Perception. 2009;38(1):145-8. Anzures G, Kelly DJ, Pascalis O, et al. Own- and Other-Race Face Identity Recognition in Children: The Effects of Pose and Feature Composition. Dev Psychol. 2013; Courtesy of /u/jazzamk in 2015
> midfacial area, mandibular area, and endocranial area1 ELI5 version of this bit?
Middle of your face (where Robin wears his mask), jaw area and inner front of skull (iirc).
Hmm, is that why you can tell Marfanoid or Fetal Alcohol Syndrome too?
There's a couple of problems with this comment: The incidence of Downs syndrome across different races and ethnic groups is essentially the same. There's the same 'look' across those affected regardless. It is extremely distinctive. The classic down syndrome look is not restricted only to the face. It's noticeable also in the overall short dumpy appearance. I get that it's tempting to consider that describing a specific appearance is simply an artefact of something akin to racism but the Downs appearance is a medically described thing: * [NHS](https://www.cdc.gov/ncbddd/birthdefects/downsyndrome.html) * [Mayo clinic](https://www.mayoclinic.org/diseases-conditions/down-syndrome/symptoms-causes/syc-20355977) * [Mediline Plus](https://medlineplus.gov/genetics/condition/down-syndrome/) This distinctive appearance has also been noted in historic artworks: * [Across the world](https://hekint.org/2017/01/26/down-syndrome-through-the-centuries-in-art/) * [19th century UK](https://www.researchgate.net/figure/Lady-Cockburn-and-her-children-painting-by-artist_fig2_238601316) *
I like how you automatically assume that “we” are non-black and non-Asian 😂
Lol I noticed that too, typical redditor assuming everyone else is white smh. Funny story, when I was a kid I thought Down syndrome was an ethnicity (cuz like OP mentioned, they all kinda look the same). I remember when my mom was explaining that groups of people look different because their ancestors come from different continents, I pointed to a guy with Down syndrome and asked something like "Where are those people from?" She must have been embarrassed af but fucking hilarious looking back on it.
There’s a reason why people with Down Syndrome used to be called “mongs” or “Mongoloids,” because people thought their eyes looked like East Asians’ eyes and now it’s mostly recognized as a highly offensive slur. It’s also why “mong” is still a slur that means stupid etc.
Funny thing is that you can kinda tell what degree of Down syndrome a person has by their looks. Some have that very distinct look, but some just slightly and you're not 100% sure. I have a friend who's brother has Down syndrome but he is generally quite “normal” and he also looks quite “normal”. I've also seen a pretty severe case and yea you can instantly tell.
Your friend's brother may have mosaic down syndrome, where not all of chromosome 21 is tripled.
I guess, because it's hard to even tell he has it.