Abstract: Objective Investigating the relationships of polymorphisms of 5,10-MTHFR gene and severe depression in northern Chinese Han population provided reliable evidences for the prevention and cure of diseases. Methods Using case-control study,We detect the gene polymorphisms of MTHFR C677T and A1298C by polymerase chain reaction-Restriction fragment length polymorphism (PCR-RFLP). Results ①The frequencies of genotypes of 677TT in control groups and that of T alleles were 13.16% and 39.80%;the frequencies of genotypes of 1298CC and that of C alleles were 1.32% and 12.83%;②The frequency of MTHFR 677T/T genotype (35.53%) and 677T allele (57.24%) in depression were respectively higher than that in control group(13.16%)(P<0.001);the differences of the frequencies of MTHFR A1298C genotype and C allele between control group were respectively no statistically significant(P<0.05);③The Ligistic regression analysis showed that the genotype of C677T was relative to the occurrence of disease,and the genotype of A1298C wasnot relative to the occurrence of disease. Conclusions The mutation of MTHFR C677T in the groups of severe depression patients was relative to the occurrence of severe depression disease,and it is the risk factors of disease;the mutation of MTHFR A1298C wasnot relative to the occurrence of the severe depression.

Key words: severe depression, polymerase chain reaction-Restriction fragment length polymorphism (PCR-RFLP), 10-MTHFR, gene polymorphism