Controversies in Autism - Genetics

Genetics

For more details on this topic, see Heritability of autism.

There is evidence that autism has a genetic component, and ongoing research focuses on finding the biomarkers that determine autistic phenotypes. One as yet unproven theory is that there may be genes which contribute to a vulnerability to environmental triggers or have another role in the etiology of autism.

Genetics is viewed as an underlying factor. Though there is a statistical pattern for a significantly high risk to have another autistic child in families with an already affected child. However, while some parents of those with autism are progressively also being diagnosed on the autism spectrum, at least some autistic children have apparently neurotypical parents. This suggests to some that genetics are either not a necessary cause or that they don't play a part in all cases of ASD, although it could also mean that the gene(s) responsible may be recessive or a spontaneous mutation. The spectrum of autistic disorders is notable for its significant gender disparity, with the incidence of autism in males greatly exceeding the incidence in females. Whilst this could be evidence for a genetic theory, it has also been argued that male brains may be more vulnerable during early development.