nclude, UDP-glucuronosyltranserase (UGT1A1; irinotecan), dihydropyrimidine dehydrogenase (DPD fluorouracil), and thiopurine S-methyltranserase (TPMT; thiopurines), among others. Nevertheless, drug efficacy is not influenced only by genetic variation in the genes that are responsible for drug metabolism. Polymorphisms in genes that encode drug targets and drug transporters have likewise been appeared to alter drug response. With an end goal to summarize and organize data on these critical pharmacogenetic genes and their variations, several organizations have curated pharmacogenetic genes records based on relevant literatures such as PharmaADME ‘Core Gene List’ (http://www.pharmaadme.org/) and the more thorough ‘Very Important Pharmacogene’ summaries compiled by the Pharmacogenomics Knowledge Base (PharmGKB; http://www.pharmgkb.org), which are published regularly in the journal Pharmacogenetics and Genomics (Stuart, 2011).
3.2 PHARMACOGENOMICS

The proceeded with identification of sequence variants, relevant genes, and associated drug response phenotypes is confirmed by the paralleled increment in pharmacogenetics literature, especially in connection to the completion of the Human Genome Project (Fig. 1). The accessibility of genome-wide sequence information around then additionally propelled the related field of “pharmacogenomics” (Fig. 1). Albeit as often as possible utilized conversely, pharmacogenetics is regularly viewed as ‘the study of drug response in relation to specific genes, though pharmacogenomics is ‘the study of drug response in relation to the genome’. The huge advances in genotyping and sequencing innovations now take into account the rapid interrogation of genetic varieties over the whole genome that has been exploited for use in pharmacogenomic-directed GWAS notwithstanding the more regular GWAS for complex diseases. In addition, profoundly multiplexed genotyping assays improved for imperative pharmacogenetic genes and functional variations have been developed for both clinical and research use, (Burmester et al., 2010) inciting the providing individuals with an anticipated medication metabolism phenotype profile. However, which variation alleles included on these boards is entirely significant is a continued source of debate.

Numerous GWAS for pharmacogenomic traits have been done to recognize g