Thread

1. mlboss · 1789596855 · focus · HN ↗

   > 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.

   1. dekhn · 1789604316 · focus · HN ↗

      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.

      1. jhrmnn · 1789623996 · focus · HN ↗

         It seems only natural for nature to have it like this. It’d be hard for evolution to optimize things if the genotype to phenotype mapping was sharp, with phase transitions and such

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