C.V.
Autism and "on the spectrum" ASDs aren't genetic duplications or deletions. They are genetic predispositions which have been expressed. I know this seems like semantics, but truly, when you're talking about genetics/heredity, the terms matter.
A test would simply determine a predisposition for autism, in the same way that you can test for a genetic predisposition for other hereditary diseases. This is pretty new, and really a huge statement by the mental health community, leading us away from the long-standing argument that autism arises environmentally or congentially.
Now, as to whether I'd have the testing. My mother has ADHD, I have ADHD, my kids have ADHD. I knew my kids had a pretty good chance of having ADHD, and I paid attention. So such testing was pretty much pointless for us. I honestly wouldn't have bothered. It wouldn't have changed a thing.
If I were a mom of a brand new baby, would I test for autism or other genetic predispositions? Well, there are pros and cons. Some, myself included, believe that a label is harmful and creates learned helplessness that a child would not otherwise experience. That's a huge con. Others believe that knowing would enable them to utilize earlier intervention services and potentially alter the outcome. That would be a pro.
I wouldn't test. I raise my kids with the mindset that there's nothing wrong with them, and that they can overcome anything they encounter. And they have.