Deligezer Ugur, Akisik E Ebru, Dalay Nejat
Department of Basic Oncology, Oncology Institute, Istanbul University, Istanbul, Turkey.
In Vivo. 2005 Sep-Oct;19(5):889-93.
Folate deficiency is implicated in cancer development. Single nucleotide polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene can modulate the effect of folate. In this case-controlled study, a possible effect of the common MTHFR C677T (ala-->val) polymorphism on breast cancer susceptibility in Turkish patients was investigated.
Polymorphism analysis was performed by melting curve analysis.
The variant allele valine (677T) was more frequent among the patients (30.1%) than in controls (23.9%). This difference was weakly significant (p = 0.046; OR = 1.37) and due to a significantly higher frequency of the valine homozygotes (677TT) among the patients (12.1% vs. 5.4%; p = 0.013, OR = 2.5). Among the patients diagnosed at more than 40 years of age, a more pronounced association of the valine homozygotes with breast cancer risk was observed (p = 0.009; OR = 3.3).
Homozygosity for the low-activity C677T genotype (TT) may represent a genetic determinant increasing breast cancer risk.
叶酸缺乏与癌症发生有关。亚甲基四氢叶酸还原酶（MTHFR）基因中的单核苷酸多态性可调节叶酸的作用。在这项病例对照研究中，调查了常见的MTHFR C677T（丙氨酸→缬氨酸）多态性对土耳其患者乳腺癌易感性的可能影响。
通过熔解曲线分析进行多态性分析。
患者中缬氨酸变异等位基因（677T）的频率（30.1%）高于对照组（23.9%）。这种差异具有微弱的显著性（p = 0.046；比值比= 1.37），这是由于患者中缬氨酸纯合子（677TT）的频率显著更高（12.1%对5.4%；p = 0.013，比值比= 2.5）。在40岁以上确诊的患者中，观察到缬氨酸纯合子与乳腺癌风险之间的关联更为明显（p = 0.009；比值比= 3.3）。
低活性C677T基因型（TT）的纯合性可能是增加乳腺癌风险的一个遗传决定因素。
