Prevalence of the C677T MTHFR gene polymorphism in Mongolian Population

Objectives: The polymorphisms of Methylenetetrahydrofolate reductase (MTHFR) gene are associated with susceptibility to birth defects, including cleft lip –palate (CL/P) and shows great diversities among varoius populations. The purpose of this study was to investigate the prevalence of the C677T MTHFR gene polymorphism in Mongolian population.

Methods: A total of 220 individuals' DNA samples were isolated from peripheral blood samples and genotyped using polymerase chain reaction followed by restriction enzyme analysis.

Results: For C677T polymorphism, the frequency of CC homozygous was 54.5%; CT heterozygous was 37.7%; and TT homozygous was 7.7%.

Conclusion: The observed distribution of the three genotypes (CC 54.5%, CT 37.7%, TT 7.7%) in the Mongolian was in significant deviation (p=0.005) compared to the Vietnamese data (CC 67.1%, CT 30.5%, TT 2.4%). The frequency of TT homozygosity was similar to those results of previous studies in Mongolians (8.3%) and other individuals without oral clefts from Middle East and Asia. The prevalence of the TT homozygous genotype in Asia seems to decrease in a roughly north to southerly direction, although the opposite is true in Europe where it increases from north to south. Further investigation of gene-gene and gene-environmental interaction might help to discover the evolutionary distribution or migration of differential prevalence of this gene variant in certain areas and racial groups, as well as discern whether racial differences in CL/P prevalence are related to differences in prevalence of this mutation.