I have an analogy, that I feel may be helpful- take it for what it's worth to you. Our son has Down syndrome- a completely genetic disorder- I am certain we can all agree on that.
We did not know until after he was born, in fact at that time (14 years ago) his blood was sent away to Texas for chromosomal testing, that took 2 weeks for the results to come back. In that 2 week time period we had time to grieve and come to terms, but even more important it gave us time to research, research, and research some more.
Within two weeks of his diagnosis being confirmed he started early intervention in Laguna Beach- he was 1 month old! He continued with services through infancy (with a brief stay due to open heart surgery at 7 months), and toddlerhood with occupational therapists, physical therapists, and speech and language therapists. He went to public school beginning at the age of 3! He rode the bus in a car seat. We were not wealthy- my husband and I were actually college students but we found and fought for services, had 2 other little girls who would love and stimulate him, and eventually surpass him.
He is now graduating from middle school- preparing to go to high school. He is in a mild to moderate class (special ed). There are approximately 8 other children at his middle school who have Down syndrome- not one of them is in the M/M class- they are ALL in the severe classroom. Only one of them speaks, and not much at that.
My son is very high functioning, and while he is about 4-6 years delayed in some instances in many, many others he is on task and typical with his peers.
I know a few of the other children's stories, not all of them but the ones I do know did NOT have, find or utilize the services we managed to.
What is the reason... if they were all born with the same genetic condition? Only one of the children has translocation trisomy 21 which would actually account for the huge difference in cognitive functioning- but the others? Was it just the way they would have come into the world had they been typical- functioning at different IQ levels on the spectrum or was it what we did for our son that made the difference.
I have an idea... especially in terms of the stories I know- It is what we did for him that made the difference. Why not the same with other genetic conditions of mental illness, PD, or sociopathy and parenting?
As I said, an analogy... take it for what you want~ Frigga