Glutathione S-transferase M1 and T1 null genotype frequency distribution among four tribal populations of western India.

Glutathione S transferase (GST) family is a key contributor in the detoxification mechanism of our body.Deletion of the genes within this family has been reported in the failure of detoxification system, to some extent leading to various types of cancers and other life threatening diseases. The existing data and reports on the association of null genotype of both GSTM1 and GSTT1 genes for various diseases are inconsistent. But knowledge of the polymorphic distributions of genotypes in different populations is important for investigating the risk factors in different epidemiological studies. The present study thus aims to determine thefrequency of GSTM1 and GSTT1 null genotype frequency among four tribal groups, i.e. Mina, Garasia, Damor and Saharia of western India. A comparative analysis with different tribal as well as world population has also been undertaken to have a view of its worldwide frequency distribution. Our results reveal a frequency distribution varying from 22.6% to 66.9% with respect to GSTM1gene polymorphism and from 19.1% to 33.0% with respect to GSTT1 gene in the studied populations. To the best of our knowledge this is the first report on the GSTM1and GSTT1frequency distribution among the tribal population of western India and our study shows that the Mina tribal population has the highest frequency of GSTM1.