Genetic polymorphism of glutathione S-transferase P1 (GSTP1) in Delhi population and comparison with other global populations

Glutathione S-transferases (GSTs) belong to a super family of phase II detoxification enzymes, which play an important role in protecting cells from damage caused by endogenous and exogenous compounds by conjugating reactive intermediates with glutathione to produce less reactivewater-soluble compounds. In the present study,we determined the frequencies of two polymorphisms in exon 5 and exon 6 of GSTP1 gene in 500 normal individuals from Delhi. GSTP1 polymorphism was analysed by PCR-RFLP using amplification refractory mutation system (ARMS) assay. Two polymorphic sites in GSTP1 (Ile105 → Val105; Ala114 → Val114) have been analysed simultaneously,which results in four alleles: GSTP1 * A (wild-type Ile105; Ala114), GSTP1 * B (Val105; Ala114), GSTP1 * C (Val105; Val114) and GSTP1 * D (Ile105; Val114). The GSTP1 allele frequency in Delhi population was 0.663, 0.248, 0.069, and 0.020 for GSTP1 * A, GSTP1 * B, GSTP1 * C, and GSTP1 * D respectively. The frequency of Ile105 and Val105 allele was 0.683 and 0.317 respectively and itwas calculated for the purpose of comparisonwith published data where all the four alleles were not analysed. GSTP1 alleles from Delhi population were compared with reported frequencies from all over India, and from other ethnic groups worldwide. This study would provide a basic database for future genetic studies.