We need to be better about how we talk about this because when we say genetic, and parents don’t have it, they can assume it’s an external cause and that’s where conspiracies and pseudoscience wiggle there way in to discussion.

Genes that cause autism can be mutated, which can happen in the womb before a woman can get a positive pregnancy test.

Or they can be inherited. In either case, a parent may show no symptoms due to recessive genes or other factors.