Case-Control Study for MTHFR and HFE Polymorphisms in Colorectal Cancer

Lee, Ryung Ah

Abstract

PURPOSE: A single nucleotide polymorphism is an important genetic variation in various pathologic situations. We examined MTHFR and HFE polymorphisms in a colorectal cancer group compared to those in a normal, healthy control group.
METHODS
Genomic DNA was isolated from whole blood of 99 colorectal cancer patients and 146 normal control patients and was subjected to MTHFR and HFE genotyping by using PCR-based restriction fragment length polymorphism analyses for the MTHFR C677T and A1298C sequences and for the HFE H63D and C282G sequences. Statistical analysis was done using SPSS 11.0.
RESULTS
The total allele frequencies of MTHFR C677T, A1298C, HFE H63D and C282Y were 0.398, 0.224, 0.014 and 0.022, respectively. The frequencies of homozygous mutants of MTHFR C677T and A1298C were 14.4% and 4.1% in the control group and 6.1% and 1.0% in the case group. There were no homozygous mutants of HFE in either group. Heterozygous mutants of H63D and C282Y were 2.1% and 4.1% in the control group and 4.0% and 5.1%, respectively in the case group. The odds ratio of a MTHFR C677T homozygous mutant was 0.604 (95% CI 0.375~0.973), and that of a MTHFR A1298C heterozygous and homozygous mutants were 0.513 (95% CI 0.298~0.883), but the difference was not statistically significant.
CONCLUSIONS
A homozygous mutant of MTHFR C677T and a homozygous and heterozygous mutant of A1298C showed a protective tendency against colorectal cancer. The HFE polymorphic mutant is quite rare in Korean population, which restricts the application of this polymorphism in a cancer epidemiologic study. The MTHFR C677T and A1298C variations should be useful predictive markers for colorectal cancer.