Homozygosity at the C677T of the MTHFR gene is associated with increased breast cancer risk in the Turkish population.

BACKGROUND: 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.
MATERIALS AND METHODS: Polymorphism analysis was performed by melting curve analysis.
RESULTS: 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).
CONCLUSION: Homozygosity for the low-activity C677T genotype (TT) may represent a genetic determinant increasing breast cancer risk.