Have you read what Anthony William (Medical Medium) has to say about autism? It's caused by heavy metals (especially mercury) in the midline of the brain. This can be inherited from one or both parents, and added to through exposure to heavy metals after birth. It seems likely to me that we all inherit inter-generational heavy metals to a lesser or greater extent, and we are all also exposed during our life via vaccines in particular. I encourage you to read Anthony's chapter on autism in his book Medical Medium for more info on this, and the history of mercury use etc