My husband's grandmother admitted there was Autism in the family.
This is a momentous event as she'd denied there was any learning difficulties at all in her family when my son was first diagnosed.
Then we were told there wasn't Autism in the family but that 'all the boys are slow at school and have odd behaviours'.
My father in law has Von Recklinghausen's Disease better known as Neurofibromatosis type 1.
There's some learning issues associated with it, he is dyslexic, also.
My husband was diagnosed with NF type 1 when he was a child, also dyslexia and ADHD; more recently he was diagnosed as being on the Spectrum, too.
A large majority of males in my FIL's family have been diagnosed as being somewhere on the Spectrum.
They are also of Indigenous descent, my husband's grandmother being of Aboriginal parentage.
Not that it's something that's admitted out in the open or discussed at all.
The extended family do enough of that to fill in the gaps.
Try Googling it, not much online at all.
Have there been studies done? Is there any idea if there is a prevalence towards any particular learning disorder? Does anyone even care?