I believe that Autism Is 100% Genetic!

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Here's a quote from Wikipedia; the article title is "Causes of Autism". The page itself is well-researched and you can go to the references for the original information:

So: 90% heritability; and most of the twins who didn't have autism ended up with autistic traits... Some environmental (probably prenatal) influence, but apparently no more than is needed to make the difference between autistic and NT with autistic traits.

More than one gene is definitely involved. Probably multiple genes. (BTW, the guy who said "more study is needed" and that the 90% figure was too high didn't actually do said study; it's a doctor's educated opinion, published in a medical journal. So no real information there yet.)

Last edited by Callista on 25 Aug 2008, 12:39 pm, edited 1 time in total.

I think more needs to be understood about those studies. But in the case of twins, there also appears to be a stress factor involved where one fetus may be compromised in some way by the other. I still haven't seen anything that supports a genetic link.

Twin-to-twin transfusion syndrome is one big risk with identicals. If they have the same placenta, one twin can get too much blood, the other not enough, and even prenatally their environments are different. So yeah. You can definitely get different environments even if they're twins.

Well Schizophrenia has always been related in my mind. I have many relatives diagnosed with schizophrenia so I can see the genetic link there, and for myself it was quite a relief to find out I "only" had autism. I know the plural of anecdote is not data, however you cannot dismiss that easily the possible connection between them.

I personally can dismiss it.

Actualy I have an uncle and a auntie who have Schizophrenia.

Can't be pure genetics. If that were true, then there would be no known causes other than genetics. And there are. (One of them, ironically enough, is a vaccine-preventable disease, when caught by the mother in early pregnancy. Thalidomide while pregnant is another -- with numbers up to, IIRC, 1 in 25 children with other thalidomide-induced features, which is far higher than in the general population. Just checked and the study title that came up with that figure is "Autism in Thalidomide Embryopathy".)

BTW, most of the people I know who were autistic due to maternal rubella, are just as fine with being autistic as any other autistic person. (Just as, actually, most people I've known who had limbs missing due to thalidomide had no desire for those limbs and had an internal/neurological body image that was identical to the bodies they had, which is very different than amputees normally feel.) So it's not necessary to claim only genetics in order to be okay with that aspect of who you are. I'm okay with many aspects of who I am that were caused by my environment, after all, and so are most people.

Also, just because some environmental factors can cause something, doesn't mean all environmental factors cause it. Thalidomide causing a higher autism rate doesn't mean vaccines do -- in fact, IIRC all the known causes of autism, whether genetic or environmental or some combination, are prenatal, because autism generally requires certain aspects of brain development which are formed prior to birth.

Also, the existence of people who have either a late onset of traits, a seeming late onset of traits, or a loss of various skills at some point (with an early onset of other traits) -- that last one being what most of the first two really are when it's looked at closely -- .. the existence of people like that doesn't mean there was an environmental trigger for them, any more than people born with a condition have to have only had genetic influences on it. Many conditions that are genetic show massive changes in development throughout a person's life. Rett's is one cause of autism that is absolutely genetic and that results in a loss of skills quite a while after birth, and then there are non-autism-related things like Huntington's disease that are genetic but that don't visibly-to-other-people show up until much later in life. Genes do not only encode what happens to us before birth, they also often create things that show up throughout the person's life.

So I don't think anyone could truthfully say it's 100% genetic, if so then why do up to 4% of children with other thalidomide-related conditions have autism as well? And why are there higher rates of autism in people whose mothers had rubella while pregnant with them than in those who don't?

Oh, and schizophrenia is so ill-defined that it probably does still encompass some people who have things that are related to autism, and was also often in the past (and probably still to some extent, just as some autistic people still receive that diagnosis instead) used to diagnose people who would now be considered to have bipolar or various learning disabilities even (some of which have been said to run in the same families as autism), as well as movement disorders including many causes of catatonia that are not themselves related to what psychiatry calls 'psychosis' in any way, and ditto certain language problems. It's not too meaningful to say that it is related to autism or is not related to autism, because it's not an "it", it's a "they" where science hasn't sorted out the difference between the wide number of things that earn that label. Until they do, you can't make statements about "it" one way or the other on just about anything given the huge number of things it actually refers to.

(Edited to clarify: The "it"/"they" comment is about schizophrenia. I think it's perfectly possible to talk about autism as an "it" because it actually has various consistently-related features in common.)

Last edited by anbuend on 25 Aug 2008, 1:14 pm, edited 1 time in total.

That whole thing about twins..., they have the same genes, then they would both have to be autistic or neither, this is very odd, something I had not expected, could the reason actually had to do with the 'environment' while you are an embryo or perhaps the form of birth?

If that were true, then autism would mean "a little bit of everything" and that's not what autism is.

Yep, very similar environments. That's why you compare identical twins to fraternal twins and to identical twins raised apart (usually through adoption) and to siblings. Fraternal twins compared to siblings show the prenatal risk factors to some degree (though the pre-birth period can actually be different for twins, and of course the siblings have the same mother--you end up with less of a difference than is actually there); identical twins raised together vs. apart show the infancy/childhood environmental effect. The problem with the second one is that you need to find autistic identical twins raised apart--and that means a VERY small sample size. You can do the same thing with siblings and adopted-out siblings of autistic children, and though you'd need more than the twins to get a good result, you could probably get more because there are more adopted autistic singletons than adopted autistic identical twins.

Social environment to some extent, granted.

But you've completely overlooked the biological environment.

While the genes are the same, the materials supplied to the developing embryos and a panoply of other biological variables see to it that their respective developments are significantly different.

Is this the MEMBER SIX that just wrote "lets stick to the eradication of autism from the gene pool" and "only a monster would choose to conceive an autistic"? www.wrongplanet.net/posts23879-start60.html . NICE!

Thanks HarryWilliams!

No, it's the MemberSix who wrote "Let's stick to the eradication of Autism from the genepool ISSUE".

The same one who also said "Given the choice of conceiving an Autistic and a non-Autistic child, only a monster would choose the former".

Why do you refuse to discuss it openly ?

You're walking a fine-line and at other times, not so fine at all, and your lack of understanding and regard shows.