Genes and Autism

This is from an interview About.com conducted May 1 with researcher Hakon Hakonarson, the lead researcher on an autism genetic database analysis conducted by Children's Hospital of Philadelphia.

Question: Could any of these genetic differences be identified in utero?

Response: Yes, all of them could be tested in utero; we have identified 10 new variations (9 rare and 1 common) and we have replicated (and confired) four other once that were previously published (neurexin 1, contactin 4, 15q11 and 22q11). However, we do not have a yes or no answer as to whether the fetus will be autistic -- but if we are testing a fetus in an autistic family the value of the test is much higher.

I know something more should be said, but I'm not sure what.

We know that autism is a set of symptoms, without a clear etiology. But, this genetic finding certainly brings us closer to understanding some of the symptoms consistent with the DSM-IV criteria for autism disorders. Experiments on mice reveal that disabling these genes results in social withdrawal, repetitive behavior, and nervousness.

We now need to study the mechanism by which this genetic variant leads to disruption in the connection between brain cells (mostly prominent in the frontal and temporal part of the brain where the CHD10 gene is expressed).

So, we turn off a gene and the mouse (or person) suddenly matches the diagnoses for autism. The personality is affected by at least 15 protein trios in the case of most people with autism. Different trio flips results in slightly different expressions of autism. (The worst condition is probably Rhett Syndrome, and we have identified its genetic cause with some precision.)

If a personality is genetically predisposed, what does that mean? Are there aspects of ourselves we cannot control? It often appears that way thanks to neurology and genetics. I usually hope the genes are only half of who we are. Maybe they are slightly more. I hope they aren't a lot more than that.