Association of neural tube defects with gene polymorphisms in one-carbon metabolic pathway

Neural tube defects (NTDs) are common congenital malformations. In this study, we aimed to explore the association between single nucleotide polymorphisms (SNPs) related to one-carbon metabolism (OCM) and NTDs in Han population of Northern China.

A case-control study was conducted in 152 children with NTDs and 169 controls. Twenty-nine SNPs in five genes were genotyped by Sequenom MassARRAY technology, and haplotype analysis was done by Haploview4.2 software.

The allele frequency of rs3733890 in betaine-homocysteine methyltransferase (BHMT) gene was statistically different between NTDs and control groups (P = 0.041), and the children with A allele had higher risk for NTDs than G allele (OR = 1.408, 95%CI 1.013-1.956). In addition, there was a statistical difference in the allele and genotype frequencies of rs1051266 in reduced folate carrier1 (RFC1) gene between cases and controls (P = 0.013, 0.034), and the risk for NTDs was also higher in children with G allele and GG genotype, compared with A allele and AA genotype, respectively (OR = 1.492, 95%CI 1.089-2.044; OR = 2.020, 95%CI 1.081-3.780). The statistical significant difference was also found in allele frequency of rs1805087 in methionine synthetase (MTR) gene between cases and controls (P = 0.031), and the children with G allele were associated with an increased NTDs risk, compared with A allele (OR = 1.664, 95%CI 1.045-2.647). Meanwhile, haplotype analysis showed C-A-A-A haplotype of BHMT, and G-G-G-T haplotype of RFC1 was correlated with an increased risk of NTDs, but C-G-A-A haplotype of BHMT and G-G-C-A haplotype of MTR might decrease the risk of NTDs.

The BHMT gene rs3733890, RFC1 gene rs1051266 and MTR gene rs1805087 were associated with the occurrence of NTDs in Han population of Northern China. It was confirmed that the gene variation related to OCM was one of the susceptibility factors for NTDs.