GSTT1 Null Genotype Distribution in the Kumaun Region of Northern India

Abstract

Glutathione S-transferases (GSTs) constitute a multigene family of multifunctional phase II metabolicenzymes. GSTT1, an important member of this group has a wide range of substrates including carcinogens.Total homozygous deletion or null genotype resulting in total lack of enzyme activity exists in populationsfor this enzyme. Since the null genotype may contribute to lower detoxification of carcinogens, this genotypeis expected to increase cancer risk. The frequency of the GSTT1 null genotype is known to vary significantlyamong populations. However, little is known about its distribution in the hilly Kumaun region of northernIndia. Therefore, in this study, we determined the prevalence of the GSTT1 null polymorphism in the Kumaunpopilation by conducting duplex PCR in 365 voluntary healthy individuals. The GSTT1 null genotype wasdetected in 18.4% of the individuals. Since GSTs play significant role in xenobiotic metabolism, the present dataon GSTT1 genotype distribution should contribute in understanding genetic association with cancer risk in thisunderstudied population.