The correlation between ploymorphisms of N~(5,10)-methylene-tetrahydrofolate reductase and essential hypertension in Han population in Ningxia

Objective To investigate the correlation between C667T point mutation of N5,10-methylene-tetrahydrofolate reductase(MTHFR) and essential hypertension(EH) in Han population in Ningxia. Methods DNA was extracted from peripheral blood in 155 EH patients and 140 normal-tensive(NT) subjects.The C677T point mutation of MTHFR gene was detected by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP),for analysis of the distribution of MTHFR gene C677T genotypes and alleles in the Han population of Ningxia and the correlation between MTHFR polymorphism and hypertension risk. Results The genotype frequencies of CC(homozygous normal),CT(heterozygous) and TT(homozygous mutant) were 37.4%,45.2% and 17.4%,respectively,in EH group;and were 52.9%,33.6% and 13.6%,respectively,in NT group.The frequencies of allele C and T were 60.0% and 40.0%,respectively,in EH group;and were 69.6% and 30.4%,respectively,in NT group.Significant difference in all 3 genotype frequencies was revealed between EH and NT group(X2=7.108,P0.05),while no significant difference was revealed in the genotype frequency of TT between the two groups(X2=0.828,P0.05).However,significant difference was revealed in T allele carrier frequency between the two groups(X2=7.091,P0.01).Meanwhile,significant higher T allele frequency was revealed in patients with EH than that in NT group(X2=5.98,P0.05).Although no significant difference in systolic blood pressure was observed between subjects with CC genotype and those with CT/TT genotype,significant lower diastolic blood pressure was observed in subjects with CC genotype(P0.05).CT/TT genotype was found as independent risk factor for EH according to binary stepwise logistic regression analysis(OR=2.604,95%CI=1.441～4.708,P=0.002). Conclusion There is correlation between MTHFR C677T gene polymorphism with essential hypertension in Ningxia Han population.Furthermore,the T allele is suggested as susceptible gene.