Abstract: Objective To study the genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR) among the Han and Bouyei populations in Guizhou and to provide genetic data for the establishment of the genetic polymorphism bank of Guizhou minorities. Methods The technique of polymerase chain reaction and restriction fragment length polymorphism ( PCR-RFLP) is used to detect the gene frequency and genotype frequency of two mononucleotide sites ( 677 and 1298) of MTHFR among the Han population in Libo County, and the Bouyei population in Libo County. Results At mononucleotide site 677, Tallele frequencies are 22.8% , 16.1%, x2 = 1.561, P > 0.1 respectively, for theHan and Bouyei. At mononucleotide site 1 298, C allele frequencies are 28.9%, 39.1%, x2 = 2.075, P > 0.1 respectively, for Han, Bouyei. The frequencies with combined heterozygote of 677CT/1298AC are 16.66% and 22.7%, respectively for the two populations. Conclusion The polymorphisms of the two mononucleotide sites ( 677 and 1298) of MTHFR are diverse between northern and southern populations of China, but they are not significantly different between the Han and Bouyei in two site. The C allele frequencies at site 1 298 of the Bouyei in Libo County are higher.

Key words: Polymerase chain reaction; Restriction fragment length polymorphism; Polymorphisms; Methylenetetrahydrofolate reductase