Autism: nature vs nurture
RFK Jr claims he will discover the “cause” of autism by September 2025. He will fail, for the simple reason that we already know that autism is a genetic disease.
Poor RFK Jr. His vaccine-autism connection has been a fail, so he’s grasping desperately for something that won’t force him to admit he’s either a dupe or a liar.
“Genetic markers alone are not going to dictate your destiny. You need an environmental toxin,” he said.
“Kennedy said his study is going to look into food additives, mold, water, medicines and ultrasounds as potential causes [of autism].”
Autism, like cleft palate, hypertension, schizophrenia and a number of other diseases, is a multifactorial disease with multiple genetic inputs. There’s zero evidence that autism is *caused* by environmental factors or could be prevented by eliminating environmental factors. In fact, studies suggest that approximately 80% of the risk for autism can be attributed to inherited genes. It is not a preventable disease, full stop.
Don’t get me wrong. There are environmental factors that do cause disease. Ultraviolet light causes skin cancer. Asbestos causes mesothelioma. Tobacco smoke causes lung cancer. Helicobacter pylori infection causes gastric cancer. There are also genetic mutations that cause increased risk of skin, lung and gastric cancer. But in the case of autism, genetics is by far the dominant factor, based on the published scientific evidence to date.
RFK Jr blames environment for autism
Poor RFK Jr. His vaccine-autism connection has been a fail, so he’s grasping desperately for something that won’t force him to admit he’s either a dupe or a liar.
“Genetic markers alone are not going to dictate your destiny. You need an environmental toxin,” he said.
“Kennedy said his study is going to look into food additives, mold, water, medicines and ultrasounds as potential causes [of autism].”
Autism, like cleft palate, hypertension, schizophrenia and a number of other diseases, is a multifactorial disease with multiple genetic inputs. There’s zero evidence that autism is *caused* by environmental factors or could be prevented by eliminating environmental factors. In fact, studies suggest that approximately 80% of the risk for autism can be attributed to inherited genes. It is not a preventable disease, full stop.
Don’t get me wrong. There are environmental factors that do cause disease. Ultraviolet light causes skin cancer. Asbestos causes mesothelioma. Tobacco smoke causes lung cancer. Helicobacter pylori infection causes gastric cancer. There are also genetic mutations that cause increased risk of skin, lung and gastric cancer. But in the case of autism, genetics is by far the dominant factor, based on the published scientific evidence to date.
RFK Jr blames environment for autism
I’m still not ruling out mercury in the water if only because of the considerable effort put out to distract us from the mercury in the water. I’ve put a lot of time into trying to figure out why I and my kids and grandkids, parents and grand-parents are as we are and I do not appreciate one dogged bit this cretin making a mockery of us to hasten his political career
I linked your earlier post today, and there’s a PBS short up about it at my house …
@Ten,
Thanks for the link!!
You’re welcome. I would add it is my conviction RFKj is an industry shill, like Ralph Nader deliberately blowing up Pintos in the seventies when there were Chevy pickups blowing up all over the place without any help. A distraction from what’s really going on.
I have this theory about conspiracy theories: about a conspiracy to put conspiracy theories out there so irrational as to discount them as fringe fantasy and condescendingly lump all conspiracy theories including valid theories of conspiracy together as irrational.
Some of what he says could be true ~ call it hiding, or dissembling behind the truth; obfuscation ~ especially environmental factors, most notably mercury in the water. Unfortunately it’s lost in the lump
@Ten,
Methylmercury in the water may or may not be a health problem. Methylmercury in fish is, because fish concentrate methylmercury in their tissues. That said, I’ve seen no evidence that the *concentrations* of methylmercury in US drinking water are hazardous, and the methylmercury levels in fish appear, on the evidence, to be safe if you don’t eat fish every day. Of course, drinking water in America also contains microplastics and endocrine disrupting chemicals, so not sure why you’re concerned about methylmercury.
There are plenty of toxins in your diet if you want to be paranoid. Baked goods have acrylamide, a neurotoxin and carcinogen. Grilled meats have known carcinogens (e.g., benzpyrenes). Most rice in America has arsenic. Preserved meats have carcinogens in the form of N-nitroso compounds formed from nitrites and nitrates, heterocyclic amines and polycyclic aromatic hydrocarbons.
Sunshine is good for vitamin D but UV-B can cause skin cancer.
To live is to risk. All this pales in comparison to the risk of death or permanent injury every time you climb behind the wheel of your car.
The director of my son’s autism school has expressed doubts over the importance of genetics in ASD. Over her career in this field she is convinced that the surge in ASD is real and not the result of better screening and awareness. To be clear, she knows there is better screening and awareness, so at a given young age, say 4, the rate of diagnosis exceeds that of 20 years ago. But screening and awareness are a continuous feature of modern pediatrics and education, such that many “non-ASD” 4 year-olds of 20 years ago would have been recognized over time, particularly through the end of high school, as ASD if that were the case. But her experience over the past couple of decades isn’t like that. Better screening and awareness applied to 6+ year-olds has hardly found any previously undiagnosed cases over her career…. They find more “now”, but scant evidence the missed many “then”. She’s convinced that the population now 25 to 30 just has much lower incidence than those now 5 to 10. For this reason she thinks the genetics angle on ASD is misleading. There may well be groups of genes that today are much more likely to be found in ASD people than non-ASD, but she suspects these same genes were much less likely to be associated with ASD 20, 40, 50 years ago than today. She’s not a geneticist, but has trouble following an argument that ASD can be heavily driven by genes but also experience a very significant change in incidence in one human generation of 20 years.
@Eric,
” . . . but also experience a very significant change in incidence in one human generation of 20 years.” Nobody is claiming that there’s been a very significant change in *incidence* in 20 years. The claim is that there’s been a very significant change in *diagnosis,* which is not the same thing.
It’s obvious that she’s not a geneticist. I am. Heritability of autism isn’t measured by allelic association. The evidence for high heritability of autism relies on quantitative measurements of twin pairs, comparing autism concordance in monozygotic twin pairs (which are genetically identical and also share the same environment) to autism concordance in dizygotic twin pairs (which are just like any pair of sibs, but share the same environment).
You have to read and understand the published evidence to be able follow the argument. Here’s a recent review:
https://pmc.ncbi.nlm.nih.gov/articles/PMC4996332/
@Eric,
Autism and ASD are diagnoses that can have distinct etiologies. ASD incidence is higher among patients with Fragile X, Kleinfelter Syndrome, Down Syndrome and neurofibromatosis type 1, all of which have an indisputable genetic etiology. The genetic etiology of the ASD in each of these distinct genetic syndromes is very likely different.
There is published evidence that the expressivity of ASD is influenced by diet and gut microbiome. Not surprising, since there is considerable evidence that diet and the gut microbiome affect brain function and cognition, and the locus of autism is in the brain. That’s not the same as causation, but whether or not a child shows up in an autism school will be influenced by (a) severity/expressivity and (b) whether they get a professional diagnosis.
Joel:
I like having you around. I do not have to study up to be able to answer Eric on this topic.