In a WebMD article, the results from a large genetic-factor-only study gleefully reports that the newest, highest-ever estimate of the percent liability of autism risk that can be attributed to “genetics” is 80%, leaving the remaining 20% to environmental factors.
The article also claims that this new, highest estimate is reported by the study authors to be “…roughly in line with those from prior, smaller studies on the issue, further bolstering their validity“.
Consistent Results From Invalid Methodology Does not Make Those Results “Valid”. It Makes Them “Consistent”.
The “roughly in line with” is an appeal to consistency. But the Liability Threshold Models differ from other approaches methodologically. Previous studies, one of which was conducted by the same group of researchers, had estimates that ranged from 0 to 99% heritability. The average, until this group started using liability-threshold models, was around 40% attribution to genetics. Their studies increased the average, but it still hovered around 50% liability. Only the liability threshold models, used by this group, show results around 80% liability. So their method is consistent with itself. No surprise there. But that’s nowhere near “roughly in line” with all prior studies.
One of those studies is discussed in the article “Non-genetic factors play surprisingly large role in determining autism, says study by group“.
Why Autism is Not “Genetic”
The article skips over the fact that the newest, latest study, like the prior studies, fails to actually measure the contribution of a single environmental factor. While the article rails against “anti-vaxxers”, the study ignores the vaccination status of those involved in the study. The mantra of so many studies never showing association has to be tempered with a mature, responsible and realistic interpretation in the context of how those studies were conducted: restricted to one vaccine (MMR), and then there is this:
Assumptions Without Measurement Lead to Assumptions as Conclusions
Their entire methodology is based on familial correlations. In the current study under consideration, no exposure levels to pesticides, medical exposures in utero, smoking history, nothing environmental was measured. And yet somehow the study authors pretend they can estimate the % liability from environmental factors. How do they pretend to achieve such a feat?
The first problem is that they have not measured any interaction between genetics and environmental factors. There is, in fact, established knowledge of special risk of autism that involves combined risk of specific genes and specific environmental factors. Check out, for example, Bowers and Erickson (2014):
Their Liability Threshold Model Approach is Both Under- and Mis-Specified
You really have to understand population genetics a bit to get this next part, so I apologize to the lay public, but please take what understanding you can from this:
Their model (generically represented) is
ASD risk = “Genetics” + e
where e = measurement error, leaving whatever variation appears to be unexplained to Environment. That’s unusual because the usual interpretation of such unexplained variation is “Error” and “Unknown Variation”. In technical terms, their model is underspecified. Environmental variation is not “Error” in a genetic model, it’s “Environmental Variation”.
If they HAD measured environmental factors, say, vaccination exposure, their model form would be
ASD risk = “Genetics” + “Environment” + e
but this model would still be underspecified.
The more fully specified model would be
ASD risk = “Genetics” + “Environment“+ “(Genetics x Environment)” + e
And if the interaction term “(Genetics + Environment)” is more highly significant than “Genetics” or “Environment“, a reasonable interpretation would be that we cannot interpret genetics in a vacuum, that the significance of many ADK risk alleles must be modified by environmental factors. If during model selection, G or E is significant, but then in the full model G x E is significant, we attribute liability to both G and E working together.
Instead of this standard approach to studying genetic and environmental contribution to phenotypic variation (ASD phenotype), they do something very odd.
In the Supplementary Material, they report that they made assumptions about environmental factors. Non-specified “Shared Environmental” effects are ASSUMED to be 1.0 for siblings and 0 for cousins. Families quite often stop vaccinating after an older sibling experiences seizures. The study authors also EQUATE “Non-Shared Environmental Factors” with “residual errors”, which is patently absurd. That’s “e“, which is unspecified variation (error), not designated environmental factors.
If I had conducted an analysis of environmental factors and their contribution to ASD, and used their methodology, I would be able to attribute any unexplained variation to “Genetics” after allowing “Environmental Factors” to consume most of the variation. I might arbitrarily add in some assumptions, such as assuming that risk from dominant alleles were 1.0 (which they are not, if the impact of those alleles are modified by environmental factors) and all recessive risk alleles contributed zero risk, which would be, as described, arbitary. Their conclusions draw directly from their assumptions.
Evidence? What Evidence?
The WebMD article cites the entire team of researchers as saying “the current study results provide the strongest evidence to our knowledge to date that the majority of risk for autism spectrum disorders is from genetic factors,” [‘said a team led by Sven Sandin, an epidemiological researcher at the Karolinska Institute in Stockholm, Sweden’]“ – as quoted by WebMD.
Evidence? What evidence? If you assume no contribution of environment, measure no environment, and conclude no contribution, there is no evidence.
There are over 850 genes that have been determined to contribute to ASD risk – and not one of them explains >1% of ASD risk individually. Most of these are Common Variants – meaning they are ancient – as in, they pre-date both the ASD epidemic (and yes, there is an epidemic) and vaccination. Here’s a figure from my book, which reviews all of the genetic and environmental studies published to mid-2016:
This explains why ASD pedigrees look like humanity dipping its toes into a toxic soup:
The study also does not explain why >20% of children with ASD have higher copy number variation – de novo genetic variation – compared to the rest of the population, nor why people with ASD – and their mothers – have anti-brain protein antibodies – nor why people with ASD have strange misfolded proteins, lifelong microglial activation, why studies of replacing the microbiome show a reduction in the severity of autism traits by 50%… a feat for a diagnosis that is allegedly 80% “genetic”… and so on, and so on.
Then There is Phenomimicry
The study ignores the fact that environmental factors can impact genes, proteins and biological pathways in a manner that is identical to the effects of genetic variation. This is called Phenomimicry – a term so cool I wish I had invented it. Examples of Phenomimicry are known in science relevant to ASD.
“Guess What? Being Human is Heritable”
It’s worth pointing out that thousands of human “traits” are heritable, and that includes traits that contribute to sociality, language ability, intellect, and even perhap tendency toward repetitive motion. That means that genetic studies must subtract the heritability of these traits in the non-ASD population from the estimate of heritability in their contribution to ASD.
The WebMD article, and the research report itself, lauds the study for involving over 2 million people from five countries. This is not impressive because the study falls into the category of “Science-Like Activities“.
No More YAHUGS
It is highly unethical – and socially irresponsible – for “Genes-Only” studies to be conducted that claim to rule out environmental factors. All “Yet Another Highly Unethical Genes-Only Study”s – YAHUGS – should be replaced with fully and correctly specified models. That means measuring and studying both vaccination patterns and genetics.
Allison Park, PA
Note: A layman’s example will help. Let’s say you want to understand thumb injuries among carpenters,and you specify a model
Risk of Injury = Hammer Size
You SHOULD also include Length of Nail, i.e.,
Risk of Injury = Hammer Size + Length of Nail
but it is socially unacceptable to conduct science on the Length of Nail. So you leave it out. You then model
Risk of Injury = Hammer Size + e
and incorrectly attribute variation in the “Length of Nails” to “e“.
You SHOULD specify
Risk of Injury = Hammer Size + Length of Nail + (Hammer Size x Length of Nail) + e
But that pesky social pressure to ignore Length of Nail goes a long way.
So you don’t know “(Hammer Size x Length of Nail)“because you do not know Length of Nail.
So you attribute everything to “Hammer Size”, totally ignorant of any direct or interactive effect of the “Length of Nail“and “Hammer Size“.
So you conclude “Hammer Size explains more than Length of Nails” when you should publish
“We Do Not Know the Effect of Length of Nails in Isolation nor with Interaction with Hammer Size”.
You can support me in my initiatives – going live in the fall with the WWDNYK Studios – join on Patreon where these and other pressing issues will be discussed with live guests.
This effort is not funded by any means, except some meager ad revenue. Your support will help me offset costs. Won’t you pitch in?
Experimental cord blood therapy for autism studied
Results from a Phase I trial were published April 5 in the journal Stem Cells Translational Medicine. The study found that among 25 children ages 2 to 5, more than two-thirds appeared to show improvements in speech, socialization, and eye contact, as reported by parents and assessed by researchers.
The study is in phase 2.
Four Year Old Boy Shows Clear Improvements in Autism Symptoms After Stem Cell Trial
The fact that children in this study improved after receiving stem cells from their cord blood speaks volume about the genetic vs environment debate.
Instead of celebrating there may be a breakthrough is what has become an epidemic among the children in this country Corporate Medicine is minimizing the results. How devoid of humanity and compassion must any person be to not want what’s best for children over what’s best for profits, power and control.?
It makes me crazy how utterly irrational and inept even many self-identified “scientists” are about the need for a study design to match what it claims to study. Some of them are — to me, at least — so OBVIOUSLY unable to answer the questions they claim to, I find it truly amazing that so many people don’t understand the problem.
Clearly, a lot of folks are manipulating the studies on purpose in order to produce “evidence” that’s favorable to the goals of Big Pharma, but I really believe we also have a lot of scientists who are just REALLY BAD at their jobs.
It is actually VERY SIMPLE to debunk any ideas that autism is genetic. Easy science.
#1 – Are any of the parents or grand-parents of an autistic kid you know autistic?
#2 – Do you think an autistic kid you know will ever be able to mate and procreate?
Here you go. Genetic theory of autism debunked.
There is no such thing as science that contradicts the facts on the ground.
Yes, just not diagnosed early in life.
Still that’s not much evidence. You need to learn the difference between anecdote and good evidence.
Good one Peter. The ol’ “No True Scotsman” fallacy to keep your delusions going. If autism is so hard to discern then we should cut off all funding for disability payments to those who have it shouldn’t we?
Interestingly, I have never once heard of a neurodiversity type ever claim that welfare payments for those with autism should stop. Weird huh? According to you, autism is a magical “gift” right? Maybe you should be taxed to support the rest of us! And yet you simultaneously want to keep the disability payments flowing but still tell us that autism is wonderful and magical and everybody should desire it.
Hey RTP, I am taxed to support the rest of you.
But, thanks for assuming I’m crippling disabled and dependent on welfare. It seems like you have a stereotype that all autistic people are.
I’m not so good at all that fancy math but doesnt the fact that if one identical twin has autism spectrum disorder (ASD), the other twin has a 76 percent chance of also being diagnosed with it but the percentage of fraternal twins who each share an ASD diagnosis is 34 percent for same-sex twins and 18 percent for boy-girl pairs mean that it’s almost all genetic?
No. Actually the fact that if an identical twin has ASD that isn’t a guarantee that the other twin also will/does is a strong indicator that it ISN’T a genetic disorder (although it seems to have a genetic element, in that certain genes can increase susceptibility).
Correct. Concordance is higher among monozygotic twins compared to dizygotic twins. In a toxic environmental, the genetic susceptibility could be, and I think is likely a susceptibility to neurodevelopmental effects of certain toxins in particular and a low ability to detoxify in general.
The question is what is the “it” that is genetic. No doubt there is an inheritance of RISK. But risk of what? Studies of the concordance of autism in siblings (co-occurrence of autism in siblings), the results indicated a weak genetic component (low concordance). Studies show a wide range of concordance, supporting a large role for environmental factors (environments vary widely). The co-occurrence of a condition among siblings is not a direct measure of the heritability of a condition. Siblings share much in their environment, most often including the same uterus, the same prenatal care, and the same medical care in the earliest stage of life.
Seems like an unnecessary complication to insert and environmental mediator between genes and ASD. Occams razor expressing basic probability theory suggests the simplest explanation consistent with data is most likely to be correct
Although autism is highly heritable within families, the genes and mutations contributing autism risk differ widely across families.
This led me to consider which biological mechanisms of pathophysiology could in fact apply, and that led me to recall research I was involved in on the unfolded protein response – the diverse genetic contribution to endoplasmic reticulum stress adds to the environmental reticulum stress in what I call ER hyperstress.
The genes with function identified relate to neurodevelopment. Endoplasmic reticulum is such a ubiquitous cellular structure one would expect widespread diverse abnormalities likely fatal, certainly not triggered by environmental factors. Maybe mitochondrial with differential effects in heavily energy dependent tissues. I think this is where your lack of biochemical and cellular training shows when you stitch together two terms with no plausible link.
no it simply means that they are likely to share: a) emotional traumas; and b) susceptibility to poisoning (aka vaccination).
Hey RTP are you saying genes have NO impact? Because it sounds like it.