Association Study of Polymorphisms in Genes Relevant to Vitamin B12 and Folate Metabolism with Childhood Autism Spectrum Disorder in a Han Chinese Population.

BACKGROUND Both genetic and environmental factors play a role in the development of autism spectrum disorder (ASD). This case-control study examined the association between childhood ASD and single-nucleotide polymorphisms (SNPs) in genes involved with vitamin B12 and folate metabolism. MATERIAL AND METHODS Genotypes of transcobalamin 2 (TCN2) rs1801198, methionine synthase (MTR) rs1805087, methionine synthase reductase (MTRR) rs1801394, and methylene tetrahydrofolate reductase (MTHFR) rs1801133 were examined in 201 children with ASD and 200 healthy controls from the Han Chinese population. RESULTS Our results showed no association of all examined SNPs with childhood ASD and its severity. CONCLUSIONS None of the examined SNPs were a risk factor for the susceptibility to childhood ASD and severity of the disease in a Han Chinese population.