A commonly carried genetic variant, rs9616915, in SHANK3 gene is associated with a reduced risk of autism spectrum disorder: replication in a Chinese population.

Autism spectrum disorder (ASD) is one of neurodevelopmental disorders with highly heritability. Recently, abnormality at the synapse is found to be important etiology of ASD. SHANK3 gene is suggested as a strong candidate gene for the pathogenesis of ASD, because it is essential for normally synaptic structure and function. We performed a case-control study to identify association between rs9616915 of the SHANK3 gene and ASD in a Chinese population. Genomic DNA was extracted from oral swabs samples of 212 patients and 636 controls and the SNP genotypes were determined by a polymerase chain reaction-restriction fragment length polymerase assay. Significant difference in genotype distribution of rs9616915 was observed between cases and controls by Pearson's χ(2) test (χ(2) = 6.92, P = 0.031). Genetic analysis of heterozygous model, dominant model and additive model showed an association of the C allele of the rs9616915 with ASD (e.g., additive model, OR 0.582, 95% CI 0.359-0.942, P = 0.028). In conclusion, our results suggested that this commonly genetic variant in SHANK3 gene strikingly decreased the risk of ASD in China.