Sun Jiazhong, Xu Yancheng, Zhu Yilian, Lu Hongyun, Deng Haohua, Fan Youjun, Sun Suxin, Zhang Ying
Department of Endocrinology, Zhongnan Hospital, Wuhan University,Wuhan, Hubei, 430071 P. R. China.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi. 2003 Apr;20(2):131-4.
To evaluate the role of methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and plasma homocysteine levels in Chinese patients with type 2 diabetes mellitus and diabetic retinopathy (DR).
MTHFR genetic C677T polymorphisms were determined by PCR-restriction fragment length polymorphism. Total plasma homocysteine levels were measured using high-performance liquid chromatography (HPLC) with fluorescence detection.
The frequencies of MTHFR T homogenetic type and CT heterogenetic type and allele T (28.18%, 41.82%, 49.09%) in type 2 diabetic patients with diabetic retinopathy were significantly higher than those in diabetic patients without retinopathy (18.37%,29.59%,33.16%) or the normal controls (17.54%, 28.07%, 31.58%). Howerver, there were no significant differences in the frequency of MTHFR genotype and allele between the type 2 diabetic patients without retinopathy and the normal controls. The presence of T allele appeared to have a strong association with the development of diabetic retinopathy. The odds ratio was 1.94 and the 95% confidence interval was 1.31-2.88. Moreover, the plasma homocysteine levels in patients with TT or CT genotype were markedly higher than those in patients with CC genotype.
MTHFR gene C677T mutation associated with a predisposition to increase of plasma homocysteine may represent a genetic risk factor for diabetic retinopathy in Chinese type 2 diabetes mellitus.
评估亚甲基四氢叶酸还原酶（MTHFR）基因多态性和血浆同型半胱氨酸水平在中国2型糖尿病及糖尿病视网膜病变（DR）患者中的作用。
采用聚合酶链反应-限制性片段长度多态性方法检测MTHFR基因C677T多态性。采用高效液相色谱（HPLC）荧光检测法测定血浆总同型半胱氨酸水平。
2型糖尿病视网膜病变患者中MTHFR基因T纯合子型、CT杂合子型频率及等位基因T频率（分别为28.18%、41.82%、49.09%）显著高于无视网膜病变的糖尿病患者（分别为18.37%、29.59%、33.16%）及正常对照组（分别为17.54%、28.07%、31.58%）。然而，无视网膜病变的2型糖尿病患者与正常对照组之间MTHFR基因的基因型和等位基因频率无显著差异。T等位基因的存在似乎与糖尿病视网膜病变的发生密切相关。比值比为1.94，95%可信区间为1.31-2.88。此外，TT或CT基因型患者的血浆同型半胱氨酸水平显著高于CC基因型患者。
MTHFR基因C677T突变与血浆同型半胱氨酸升高倾向相关，可能是中国2型糖尿病患者发生糖尿病视网膜病变的遗传危险因素。
