Somalis may well have a very high incidence of autism that no one has ever studied before.
Give you another example ~ Western Europeans in Europe and the United States have a cholesterol problem. People from far northern Europe and SE India don't.
Until quite recently it was believed this was a result of their diet and high levels of outdoor activity. More recently they've come to believe it's hereditary.
They look quite different really.
You’re absolutely mistaken if you think that people wouldn’t notice 1-in-28 children of any generation being autistic, doctor or no doctor.
Hmmm, I don’t know about Northern Europeans, but Indians who come to the US (or the west in general) have a fairly high rate of heart disease. Yes, diet absolutely plays a part in Heart Disease, is anyone surprised.