Theories about what might cause ASD have changed over the past sixty years. In some families, there appears to be a pattern of ASD or other disabilities. It also appears that some children are born with a susceptibility to autism, but researchers have not yet identified a single “trigger” that causes autism to develop1.
Evidence supporting a significant genetic contribution to ASD has been increasing over the past few decades, but what causes or increases the risk for ASD is not yet understood2.
Research has begun to show that environmental factors may also involve some genetic susceptibility. A recent study shows that at an individual level, the risk of autism increases according to how close you are genetically to other relatives with autism4.