alt Hacker News> Autism is genetic. You’re born autistic and you’re autistic for life. Most autistic people are autistic because of genes they got from their parents. This is why autism often runs in families. Much less commonly, other factors can play a role, but usually in combination with genes from parents. There isn’t a single ‘autism gene’. Thousands of genes combine to make a person autistic. Scientists have identified many of these genes, but they think there are still many more to find. And there is no genetic test for autism. We don't fully understand how genes combine to make a person autistic. It is complex and no simple test can give an accurate answer. Genetic testing cannot predict whether a child will be autistic or not, and it can’t be used to diagnose someone as autistic.
Autism is genetic but we cannot do genetic testing and prove that you have autism. Seems like a very circular reasoning.
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I understand that they found strong enough evidence that it's a genetic condition, but at the same time it's not one single gene, it's a combination of many that combine to create the full spectrum, hence no easy genetic test. They'll get there in time as technology and research evolve. I don't see any circular reasoning.
EDIT: they have a FAQ about it: https://www.autism.org.uk/advice-and-guidance/about-autism/w...
Height has a strong genetic component, but there's no test for height.
If your C code causes a segfault, is it fair to reason that there's a memory management error in the code? Does that make it practical to find where, so that you can just add a check for it?
That seems like a pointedly naive viewpoint. You can have clearly predictive population level statistics about prevalence in family groups without clearly understanding the (very messy and unbelievably complicated) way that genetics shapes brain development.
Some of what you've quoted highlights my own belief on some of this:
Autism is also multiple things.
That may provide some insight about how there is not a "single `autism gene'" and how they hedged a bunch of these statements with "most" or "usually".
Maybe some day when we as a species understand brains better, some people will get a more precise label than "on the autism spectrum".
I would expect it's not caused by genes themselves, but by control DNA. That's where a lot of the subtle structural stuff happens. But that's also hard to test for. It's like how you can't test how tall someone is going to be.
I've also read ages ago in Scientific American that the difference between our brains and chimp brains is almost entirely in control DNA, not in genes. It matters a lot, but is often overlooked. (It used to be called "junk DNA", before people realised how important it was.)
Opened this link to quote that. The level of reasoning is "trust me bro". Even if some things must be simplified for uneducated reader, the quote from above should be embarassing for author to write
My understanding is that having certain genes makes conditions like Autism more probabilistic than deterministic.
can't wait until large scale datasets and LLM powered studies either debunk or confirm and quantify the effects objectively.
Genetics is complicated enough that both things can be true without circular reasoning.
I've studied genotype to phenotype mechanisms for a very long time (but from the lens of molecular biology, biochemistry, and biophysics, rather than genetics). The language of genetics- especially in the popular press- is extremely loose and ambiguous, and people trying to understand the genetics of autism using the popular press (or even 8th grade biology genetics) are going to be very confused.
Basically in medicine and biology in general it's best to be flexible- avoid using logical reasoning, instead adopt probabilistic mindset, and assume that the entities you're reasoning about are extremely complex and you only have a small amount of noisy, partial information that is in a highly encoded feature space. You can often measure relationships or statistical linkages that appear significant (even after multiple test correction) but rarely discern the true causal relationship between the feature vector (genome) and the outcome (autism).
One of the biggest surprises in modern genetics is that many phenotypes are determined by the sum of effects of many gene products, including many complex interactions between those gene products. Some phenotypes are linked to 1000+ genes, and there are "only" ~25K genes in the human genome. The whole thing is just crazy and our ability to test for complex phenotypes continues to be very limited.