Frequency of methylenetetrahydrofolate reductase C677T polymorphism in patients with cardiovascular disease in Eastern Saudi Arabia

OBJECTIVE: Homozygosity for the C677T mutation in the gene of the thermolabile enzyme 5,10 methylenetetrahydrofolate reductase (MTHFR) associates with reduced enzyme activity, leading to mild hyperhomocysteinemia. We now know that an elevated level of homocysteine is an important risk factor for cardiovascular disease (CVD). The objective of this study was to determine the prevalence of the C677T mutation in Saudi patients diagnosed with CVD.

METHODS: Over a period of 2 years (2003-2004) in a case control study, we determined the prevalence of the C677T mutation in 83 CVD patients and in 40 age and gender-matched controls in the Eastern Province of Saudi Arabia. We determined the MTHFR genotype by restriction fragment length polymorphism and allele specific hybridization procedures.

RESULTS: The CVD group showed over representation of the C677T allele frequencies (20.5%) compared with unaffected controls (15%) (p=0.3). Furthermore, the genotypic data indicated that the prevalence of homozygosity for the C677T mutation was dramatically higher in the CVD patients (10.8%) when compared with normal (0%) (p=0.058).

CONCLUSION: These results suggest that the MTHFR C677T variant mildly influences CVD. However, we require further investigation in large independent samples.