Genetic association between SHANK2 polymorphisms and susceptibility to autism spectrum disorder.

Autism spectrum disorder (ASD), as one of early-onset neurodevelopmental disorders, is characterized by the following symptoms, including repetitive and stereotyped behaviors, impairments in social interaction, and dysfunctions in communication. ASD afflicts ∼1.5% of children aged 8 years in America and ∼4.5‰ of children aged 0-6 years in China. Existing studies suggest that SH3 and multiple ankyrin repeat domains protein 2 (SHANK2) is implicated in ASD. However, associations between SNPs in SHANK2 introns and ASD risk have been less investigated. In this study, on the basis of case-control study (226 cases and 239 controls), we selected nine SNPs (rs76717360, rs11236697, rs74336682, rs77950809, rs17428526, rs35459123, rs75357229, rs61887413, and rs77716438) in SHANK2 introns to investigate genetic associations between SHANK2 polymorphisms and susceptibility to ASD using improved multiple ligase detection reaction (iMLDR). We identified that the polymorphism of rs76717360 was associated with risk of ASD in Chinese population; the haplotype of rs11236697 C (T) or rs74336682 G (A) increased ASD risk; and haplotypes with ≥ five SNPs containing rs11236697 and rs74336682 were associated with risk of ASD. Our results indicate SHANK2 is a susceptibility gene for ASD in Chinese children.