The objective of this study was to evaluate prevalence estimates of MTHFR C677T and the CBS insertion of 68-bp (844ins68) polymorphisms among individuals with cardiovascular disease (CVD).
Our results not only highlight the involvement of the MSR and CBS genes in the etiology of cardiovascular disease, but also emphasize the strength of haplotype analyses in association studies.
Mild impairment of CBS function could therefore affect homocysteine concentration, in particular after methionine loading, and consequently cardiovascular disease (CVD) risk.
The 31 bp VNTR in the CBS gene is associated with post-methionine load hyperhomocysteinaemia that may predispose individuals to an increased risk of cardiovascular diseases.
However, folate deficiency, either associated or not associated with the thermolabile mutation of the N(5,10)-methylenetetrahydrofolate reductase, and vitamin B(6) deficiency, perhaps associated with cystathionine beta-synthase defects or with methionine excess, are believed to be major determinants of the increased risk of cardiovascular disease related to hyperhomocysteinemia.
Heterozygosity for the 833T-->C mutation in the CBS gene was observed in one individual of the control group but was absent in patients with premature cardiovascular disease.