I'm interested in how the New York Times struggles to cover stories on genetics. For example, they report that a "tiny fraction" of autism cases are explained by having certain rare genetic mutations. Scientists hope to explain 10-20 percent of autism cases by identifying yet more rare gene mutations in the next couple of years.
OK, first, why call them "mutations"? We're each born with different gene variants, that's what makes us unique. When I think of "mutations" I think of DNA damage caused by exposure to radiation, which it's not.
Second, the article complains that "There are likely hundreds, perhaps thousands, of rare mutations that could disrupt brain development enough to result in social and developmental delays."
So what? There's no single gene variant for autism. Instead, there may be thousands. But if you sequence someone's entire genome, it's no harder for a computer to scan for thousands of variants than it is to find one.
In other words, there's an emerging "signature" for autism in our genes, not a single gene. That might make it harder to develop a genetic test for autism, but not that much harder, especially when the price of a full genome scan falls below $1000.
At that point, anyone with a family history of autism will be encouraged to have a genetic test, similar to a test for Down Syndrome. It will be a test for the "genetic signature" of a disease.