People with autism tend to carry mutations that duplicate or delete several genes at once, according to a large study published 1 May in the American Journal of Human Genetics.

Children of women who have attention deficit hyperactivity disorder are at increased risk for autism and attention deficit, according to a study published 21 January in the Journal of Child Psychology and Psychiatry. This suggests the two diseases have common risk factors.

In families with a history of autism, the affected children are seven times more likely to also have epilepsy than their unaffected siblings, according to a study published 1 December in Molecular Autism. The results suggest that epilepsy and autism share some risk factors.

Variants in a language gene linked to autism are only modestly associated with the disorder in a large sample, according to a study published 17 October in PLoS One.

Children who have older siblings with autism are seven times more likely than those in the general population to receive autism diagnoses themselves, according to a large Danish study published 19 August in JAMA Pediatrics.

Researchers can increase the power of studies that link genetic variants to autism by factoring in potential subgroups of the disorder, according to a report published 26 June in PLoS One.
 

A 36-question survey detects features of autism in as much as 23 percent of parents of children with autism and 9 percent of control parents, researchers reported 20 February in Autism Research.

Members of families that have multiple children with autism have more features of the disorder than do those from families that have only one child with autism, according to a study published 2 November in the Journal of Autism and Developmental Disorders.

Individually, common genetic variants confer little risk for autism. But taken together, they may contribute significantly, predicts a statistical analysis published 15 October in Molecular Autism.

A genetic defect in the synthesis of carnitine, a molecule that is essential for proper mitochondrial function, might slightly increase risk for autism in some children, according to research published 8 May in the Proceedings of the National Academy of Sciences.