Researchers have found a complex of 3 genes that are responsible for 9% of cases of stuttering, especially among people of Asian descent. They think stuttering is 50% to 70% heritable.
There is nothing really unexpected about this. It has been a long time since anybody has believed stuttering was caused by bad parenting. It's just another brain dysfunction.
So we have another case where genetic susceptibility to a dysfunction can be known. Once we know it, how do we treat the kids differently to reduce the risk or ameliorate the problem?
The thing that jumped out at me is the statement in the article that stuttering affects up to 1% of the adult population, which is about as many as have autism, schizophrenia, bipolar disorder (not counting all the kids misdiagnosed as bipolar), and high aggression. The one percents add up to quite a large number of people with one or another things wrong with their brains.