OBJECTIVETo assess the association between polymorphism of methylenetetrahydrofolate reductase (MTHFR) gene C677T locus and nonsyndromic cleft lip with or without cleft palate (NSCL/P) in Shanxi Province of China.

METHODSBlood samples from 150 patients and their parents and 150 controls and their mothers were collected. The polymorphism of MTHFR gene C677T locus were analyzed by the methods of polymerase chain reaction and restriction fragment length polymorphism technique(PCR-RFLP). Case-control analysis, transmission-disequilibrium test(TDT) and haplotype-based haplotype relative risk analysis(HHRR) were used to study the correlation between the gene mutation and NSCL/P.

RESULTSHardy-Weinberg equilibrium test results showed that, the offspring and mother genotype in the case group and the control group was not deviated from the Hardy-Weinberg law of genetic equilibrium (P > 0.05). The distribution of genotype CC, CT and TT in offspring had significant difference between the two groups (P < 0.05). In the offspring and mother of case group and the control group, the carriers of the TT genotype compared to CC genotype, the OR are greater than 1 and 95% CI do not contain 1 (offspring OR: 2.692, 95% CI: 1.319-5.495; mother OR: 2.469, 95% CI: 1.136-5.363). The distribution of C allele and T mutation gene were significantly different in the offspring and mother between the two groups (P < 0.05). The TDT test showed: chi2 = 4.507, P < 0.05. The HHRR test showed: P < 0.05.

CONCLUSIONThe single nucleotide polymorphism of MTHFR C677T locus is associated with the development of NSCL/P in Shanxi Province.