Xu H, Chen Z, Tang J
Division of Coronary Heart Disease, Fu Wai Cardiovascular Hospital, CAMS & PUMC, Beijing 100037.
Zhonghua Yi Xue Za Zhi. 1999 Jun;79(6):414-6.
To study genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR) C677T and cystathionine beta-synthase(CBS) T833C related to homocysteine metabolism in patients with coronary heart disease (CHD).
209 patients with CHD and 101 controls were selected. MTHFR genetic C677T polymorphism was determined by PCR-RFLP, and CBS T833C polymorphism by ARMS method. Plasma homocysteine levels were detected with HPLC.
The frequencies of MTHFR T homogenetic type and heterogenetic type (27.8% and 45.4%) in case group were higher than those in normal group(22.8% and 34.6%). There were significant differences in the frequencies of genotypes and alleles between two groups (P < 0.05). C homogenotype of CBS gene was found in 21 patients, and 2 in the normal group. There were evident differences in the frequencies of genotypes and alleles of the two groups (P < 0.001). Moreover, plama homocysteine levels were markedly higher in patients with MTHFR or CBS genetic mutation than those in patients without mutation (P < 0.05).
Hyperhomocysteinemia is an independent risk factor of CHD. MTHFR and CBS are the main enzymes related to homocysteine metabolism. Their genetic mutations are possibly important mechanism of hyperhomocysteinemia and coronary heart disease.
研究冠心病（CHD）患者中与同型半胱氨酸代谢相关的亚甲基四氢叶酸还原酶（MTHFR）C677T和胱硫醚β-合成酶（CBS）T833C的基因多态性。
选取209例冠心病患者和101例对照者。采用聚合酶链反应-限制性片段长度多态性（PCR-RFLP）法检测MTHFR基因C677T多态性，采用扩增阻滞突变系统（ARMS）法检测CBS基因T833C多态性。用高效液相色谱法检测血浆同型半胱氨酸水平。
病例组中MTHFR基因T纯合型和杂合型频率（分别为27.8%和45.4%）高于正常组（分别为22.8%和34.6%）。两组间基因型和等位基因频率存在显著差异（P<0.05）。CBS基因C纯合型在21例患者中发现，正常组有2例。两组基因型和等位基因频率存在明显差异（P<0.001）。此外，MTHFR或CBS基因突变患者的血浆同型半胱氨酸水平明显高于无突变患者（P<0.05）。
高同型半胱氨酸血症是冠心病的独立危险因素。MTHFR和CBS是与同型半胱氨酸代谢相关的主要酶。它们的基因突变可能是高同型半胱氨酸血症和冠心病的重要机制。
