Genetic polymorphism of CYP2D6 in Karnataka and Andhra Pradesh population in India.

To study the prevalence of cytochrome P-450 2D6 (CYP2D6) polymorphism in Karnataka (KA) and Andhra Pradesh (AP) population. Two hundred and eleven healthy human volunteers participated in the study (100 from KA and 111 from AP). At bed time, after voiding their bladder, the volunteers ingested 30 mg of dextromethorphan hydrobromide (DM). Urine samples were collected for 8 h. DM and its metabolite dextrorphan (DT) were estimated in the urine using HPLC. The metabolic ratio (DM/DT) was used for phenotyping. The prevalence of poor metabolisers (PM) in KA is 4% and AP is 1.8%. The frequency of PM phenotype in South Indian population is in between the Western and Oriental population.