Autism is a heritable disease, but the contribution of genetic factors is not straightforward. The symptoms and severity of autism spectrum disorders vary greatly between affected individuals, and relatives often show milder, but related, cognitive and behavioral difficulties. Some genetic defects have been linked to autism, but the resulting phenotypes could be influenced by other factors such as environmental variables and the parent from whom the mutations were inherited.

Anthony Monaco and Anthony Bailey at the University of Oxford aim to untangle some of these complex relationships using a multidisciplinary approach. Two areas of chromosomes 2 and 7 have been associated with autism, and the researchers propose to analyze a set of families with autism to identify the specific sequence variations in those areas that are most strongly linked to the disorder. Once the susceptibility genes are identified, the researchers plan to examine the normal function of the genes, how their function is altered by the variants, and how those alterations might contribute to the disorder.

In addition to the genetic studies, the researchers plan to assess the social abilities, facial recognition skills, behavioral traits and neurological characteristics of the affected individuals, their parents, and unaffected siblings. This information, along with the genetic results, may help understand how the autism-linked sequence variants are inherited, and how they result in a range of symptoms. Information on autism-linked genetic variants, the cellular pathways they affect, and their phenotypic consequences may also help identify factors that could be targeted to alleviate symptoms of autism.