I think it is genetic but like alot of people on this board We don't have any one else in the family that has been diagnosed with Autism. Now that they have made the spectrum so wide we do see relatives who had poor social skills,preferred to be alone, never married. there are a number of realtives that had speech delays, are they on the spectrum who knows? Both of my older boys had speech issues. My 27 year old had ST in school because he could not tell letter sounds apart though he spoke very early. My 25 year old was delayed in both receptive and expressive. He also had really poor social skills. he had a hard time sleeping, wanted odd foods like all of his sandwiches dipped in water,he had seizures and temper tatrums At the time he was diagnosed with adjustment to childhood disorder. Because he was physically disabled with kidney failure and spent most of his life up to age 5 in the hospital. They felt his inability to socialize with children his age and the fact he got along better with adults was because of this. looking back now It would not suprise me at all if he is on the spectrum. My parents say when i was young they first thought I was retarded or deaf because I just sat there wherever they put me and did not speak till I was 5. Remember this was 50 years ago. They did finally send me to a school for deaf children hoping I would learn sign lang. I only went 1 year before I started speaking. I do remember hearing and understanding people I had thoughts and spoke to myself in my head but it was almost like there was no connection with my mouth. I did eventually go on to skip 2 years of school and graduated high school at 15 with a 4.0 average . I went to college and had my Ba. in 2 years also with a 4.0. I still struggle with lang. at times and have issues with social things. Autism spectrum? probably!