Genotypes 677TT and 677CT+1298AC of methylenetetrahydrofolate reductase are associated with the severity of ulcerative colitis in central China

在中国中部地区，亚甲基四氢叶酸还原酶的677TT和677CT+1298AC基因型与溃疡性结肠炎的严重程度相关。