My younger brother has autism so does that mean that its been passed through genes from others in my family?

Question: My younger brother has autism so does that mean that its been passed through genes from others in my family?
- Keywords:
  autism,
  family,
  passed
Asked by KatieKildeaXO to David on 8 Mar 2018.
- David Howard answered on 8 Mar 2018:
  
  Autism is partly due to genetic factors, although there are a number of different genes involved and there are some environmental factors too. This makes it very hard to know who exactly will develop the disorder. Without providing DNA samples it would not be possible to be certain whether members of your family carry the genes that increase the risk of autism.

Question: My younger brother has autism so does that mean that its been passed through genes from others in my family?