Genetic polymorphism of CYP2D6 in patients with cardiovascular disease -- a cohort study

BACKGROUND: Cardiovascular diseases are complex diseases that are influenced by both environmental and genetic factors. CYP2D6 found in the brain and the heart is involved in the metabolism of many environmental and some endogenous substances and neurotransmitters responsible for maintaining homeostasis. This raises an interesting hypothesis that it may have a role in the development of or protection against cardiovascular diseases. OBJECTIVE: To study the distribution of genotypes of CYP2D6 among patients with cardiovascular diseases in Malaysia. METHOD: We obtained DNA from 128 patients who were followed up for cardiovascular diseases. Polymerase chain reaction-based methods were used to determine common CYP2D6 alleles. RESULTS: One hundred and twenty-eight patients were enrolled. Most of the patients also had concurrent illnesses. Eleven genotypes were identified in the patients and 41% carried CYP2D6*1/*10. The second most common genotype was homozygous for the wild type gene, followed by homozygous CYP2D6*10/*10 at 14.48 %. A small percentage of the patients were heterozygous CYP2D6*1/*4. One patient was genotyped homozygous CYP2D6*4/*4 predicting a poor metabolizer prevalence of 0.78% (95% CI +/- 1.52%). Analysis using Hardy-Weinberg equilibrium showed that all of the gnotypes were consistent with equilibrium except for CYP2D6*1/*10 (chi(2); P < 0.05). CONCLUSION: Our study suggests a possible involvement of CYP2D6 genotypes in cardiovascular system diseases, which need to be validated by further studies.