> there is no evidence of gene expression for autism.

The fact that we haven't identified candidate genes for autism and a bunch of other mental health issues doesn't mean these aren't hereditary or have hereditary triggers that make outbreaks easier.

> if anything it is epigenetic caused by environmental pollutants and hormone exposure

Doubtful. The difference to older times is, we now properly diagnose mental health issues instead of just labeling affected people as "loons", locking them away in institutions or, like it happened with witch-burnings and in the NS Aktion T4, outright murder them.

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ricardobeat 5 days ago | parent [-]

You don't have to identify the root cause for that though, all it takes is studying the prevalence of a disease across family trees, that would be evidence of genetic expression.

	▲	wizzwizz4 5 days ago \| parent [-]
		Autism appears to be hereditary, but the eugenicists haven't identified a genetic component (nor have any other researchers, who are admittedly less motivated to find one). We're pretty sure that autism is a developmental condition, but the correlations with other things are… weird. (Off-hand: fœtal androgen and œstrogen levels, some chromosomal disorders, some mitochondrial disorders, a handful of rare single-point mutations, maternal autoantibodies, gut flora, something something oxidative stress (doesn't replicate, but keeps coming up).) Maybe they all tie into a "single cause" somehow, but… well, there's no single cause for eye colour (developmentally a much simpler trait), so the whole idea that autism is a deviation from the baseline, explicably attributable to a single factor, is somewhat of an article of faith.