OBJECTIVETo study the relationship between the plasma homocysteine (HCY) level and the polymorphism of N(5), N(10)-methylenetetrahydrofolate reductase (MTHFR) gene C667T in liver cirrhosis.

METHODS112 normal subjects and 87 liver cirrhosis patients were recruited in the study. Their plasma HCY levels were measured using high performance liquid chromatography with fluorescence detection and polymorphisms of their MTHFR gene were analyzed using PCR-RFLP.

RESULTSThe mean level of plasma HCY was significantly higher in patients with liver cirrhosis (21.71+/-4.86) micromol/L than that in healthy individuals (8.34+/-3.59) micromol/L. There were three kinds of MTHFR genotypes: +/+ (TT, homozygous mutation), +/- (CT, heterozygous mutation) and -/- (CC, wild type). The frequencies of the three genotypes were as follows: +/+, 29.9%; +/-, 52.9%; -/-, 17.2% in cirrhosis patients and +/+, 19.6%; +/-, 33.9%; -/-, 46.4% in normal subjects. The frequency of homozygous or heterozygous mutation was significantly higher in cirrhosis patients than that in the normal control. Moreover, plasma homocysteine level was markedly higher in patients with MTHFR genetic mutation than those without mutation.

CONCLUSIONSHyperhomocysteinemia may be an independent risk factor for liver cirrhosis. MTHFR is the main enzyme related to homocysteine metabolism. The genetic mutation of MTHFR C667T is possibly an important mechanism of hyperhomocysteinemia in liver cirrhosis. The level of plasma homocysteine may be an early indicator for liver cirrhosis.

Female ; Homocysteine ; blood ; Humans ; Hyperhomocysteinemia ; complications ; genetics ; Liver Cirrhosis ; complications ; genetics ; Male ; Methylenetetrahydrofolate Dehydrogenase (NAD+) ; genetics ; Point Mutation ; Polymorphism, Genetic

OBJECTIVETo establish a method for detecting the polymorphism of methylenetetrahydrofolate reductase gene (MTHFR).

METHODSThe MTHFR was amplified, and the amplified products were detected by denaturing high performance liquid chromatography (DHPLC), and the amplified MTHFR was confirmed by sequencing and restriction enzyme digesting.

RESULTSA total of 334 individuals of Han people in southern China were recruited in our study, and their polymorphisms of MTHFR were detected. The accurate rate of the DHPLC method, that was very sensitive with 100% detection rate available, was over 99%. The frequencies of CC, CT and TT genotypes were 56.9%, 38.3% and 4.8% individually, and the frequencies of T and C alleles were 23.95% and 76.05% individually.

CONCLUSIONThe DHPLC method can detect polymorphism of MTHFR rapidly, effectively and economically. And there is the existence of different MTHFR polymorphisms in area and race.

Adult ; Aged ; Aged, 80 and over ; Alleles ; China ; ethnology ; Chromatography, High Pressure Liquid ; methods ; DNA Mutational Analysis ; Female ; Humans ; Male ; Methylenetetrahydrofolate Dehydrogenase (NAD+) ; genetics ; Methylenetetrahydrofolate Reductase (NADPH2) ; genetics ; Middle Aged ; Nucleic Acid Amplification Techniques ; Polymorphism, Genetic