CYP2D6 Gene Polymorphism in Pakistani Population

CYP2D6 is an important enzyme mediating phase I metabolic reactions and is involved in metabolism of 20-25% of the clinically useful drugs. High frequency of polymorphism in CYP2D6 gene has resulted in the categorization of individuals as poor, intermediate, extensive and ultra-rapid metabolisers of CYP2D6 substrate drugs. The CYP2D6 polymorphism significantly affects the pharmacokinetic profile of about 30-40% of CYP2D6 drug substrates which are about 10% of the clinically used drugs thus leading to altered therapeutic efficacy of the substrate drugs and adverse drug reactions. It has been estimated that predictive CYP2D6 genotyping can be beneficial for optimum therapy with CYP2D6 drug substrates. Because of wide geographic and ethnic variability in CYP2D6 genotypes, pharmacogenomics studies to find interethnic and geographic differences in CYP2D6 genotypes are however mandatory to get benefit from predictive genotyping. This review was therefore conducted to enlist pharmacogenomics studies conducted on Pakistani population to find frequency of CYP2D6 genotypes in this region.