If none of your family has autism how did you get it?

Autism is still believed to primarily be down to genetics. Two Neurotypical parents can still have an Autistic child - they may carry the genes even if they are not Autistic themselves, or a theory is that mutations in part of the genes in both parents can pair together to lead to Autistic offspring.

I'm the only Autistic person in my family - 7 siblings on my mothers side, 13 siblings on my fathers side, and within the entire family including all my cousins I'm the only Autistic person.