People with autism are twice as likely as controls to have mutations that disable both copies of a gene, according to preliminary research presented Wednesday at the Autism Consortium Research Symposium in Boston.

Thomas Bourgeron discovered the first rare mutation linked to non-syndromic autism, pointing to neuronal connections as prime drug targets.

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.

Parents enroll their children in genetic research studies because of the opportunities to meet other families in the same situation, take control of their circumstances, and validate the medical nature of their child’s condition, according to a report published 11 July in the Journal of Autism and Developmental Disorders.

Researchers have launched an effort to yoke together disparate gene sequencing projects in the U.S., Canada and the U.K., aiming to double the number of known autism-related genes in the next three to four years.

By sequencing the protein-coding region of the genome of a single affected family member, researchers were able to diagnose 20 percent of people in 85 consanguineous families with unknown neurodevelopmental disorders, according to research published 13 June in Science Translational Medicine.

To find the pathogenic mutations in complex disorders such as autism, researchers may need to conduct sophisticated analyses of the genetic functions that are disrupted, says geneticist Aravinda Chakravarti.

Rare variants make up the vast majority of human genetic variation, according to two independent papers published in May in Science. That means that genetic studies of complex diseases such as autism are likely to require tens of thousands of participants.

By screening for recessive mutations, which are present in both copies of a gene, researchers have identified four autism candidates that may be involved in neuronal signaling, according to a study published 12 April in PLoS Genetics.

In the last three years, autism researchers have gone from sequencing single genes to whole exomes, as highlighted at the Translational Neuroscience Symposium in Switzerland last week.