ABSTRACT
India is one of the most diverse countries in the world. There are more than 200 languages spoken in India and 2 2 of them are considered official language. The population is segregated into endogamous groups based on religion (Hindus, Muslims, Christians, Bud dhists, Sikhs etc.), caste and ethnicity. Studies are under way in various aspects o f pharmacogenomics in the subcontinent, especially aimed at determining interindividual vari ability in drug response with regard to genetic polymorphisms in drug metabolizing enzymes, drug transporters and targets. Studies are also focusing on identification of disease susceptibil ity markers. Many of these studies are SNP (single nucleotide polymorphisms) based approaches. These are used to identify the frequency distribution of various polymorphisms in different ethnic groups of India and thereby predict a subset of the population who would benefit most from therapy. In this review, we focus on studies related to polymorphisms in genes encoding enzymes involved in Phase I (CYP2C9> C YP2C 19, C Y P 2 D 6 and CYP2E1) and Phase II (G S T and N A T ) drug metabolism, and the extensively studied 3435C>T polymorphism in the A BC B I gene which codes for the multidrug resistant (MDR-1) or P-glycoprotein transporter. Not much work has been done on pharmacological targets of drugs (receptors and proteins) but the available information has been included in the review.
