Mutations in the gene SHANK2 are reported in individuals with autism spectrum disorder and intellectual disability, as reported in this week in Nature Genetics. The findings strengthen the link between defects in synaptic structures and autism. In a second study mutations in the gene IQSEC2 are shown to cause intellectual disability in four separate families.
Autism is a pervasive neurodevelopmental disorder that occurs in approximately 1 in 110 children in the United States, with tens of millions affected individuals worldwide. Individuals with autism display deficits in social interaction and communication skills and also exhibit repetitive or stereotypic patterns of behavior. Several genes involved in the synapse―a junction between two neurons where signals are transmitted―have previously been associated with autism, suggesting intact synaptic structures are important for typical development of language, social and cognitive skills. Intellectual disability, or mental retardation, is a clinically distinct, more common disorder affecting 1 in 50 in the general population.
Gudrun Rappold and colleagues analyzed 580 patients with intellectual disabilities or autism and identified mutations in SHANK2 in several unrelated individuals. In another study, Jozef Gecz and colleagues show that mutations in IQSEC2 causes intellectual disability in four separate families.