Deletion polymorphism of glutathione S-transferases M1 and T1 in the Tunisian population.
Glutathione S-transferases (GST) play a vital role in cellular defense against environmentally toxic compounds. These enzymes present a genetic deletion polymorphism, which varies with ethnicity. To evaluate the frequencies of homozygous deletion of GSTM1 and GSTT1 genes in Tunisian population. On the basis of multiplex PCR protocol, the frequency of the deleted genotypes of GSTM1 and GSTT1 genes was evaluated on 145 healthy Tunisian subjects. We found that 34.6% of the individuals had the GSTM1 null genotype, 16.6% had the GSTT1 null genotype and 4.82% had a double deletion of both GSTM1 and GSTT1. The distribution of GSTM1 null in Tunisians is rather in the range of black populations and is lower than that reported in Asians, Arabs and Caucasians. However the frequency of GSTT1 null is in the range of several populations studied except Asians. The double deletion frequency seems lower than that described in different populations.