Simultaneous characterization of glutathione S-transferase M1 and T1 polymorphisms by polymerase chain reaction in American whites and blacks

Human glutathione S-transferase (GST) M1 and T1 enzymes exhibit genetic polymorphism, with a percentage of normal individuals exhibiting a homozygous deletion of the relevant genes. We established a differential polymerase chain reaction (PCR) technique to simultaneously characterize inactivating mutations responsible for the null alleles of GSTM1 and GSTT1. Primers for GSTM1, GSTT1, and for β-globin (as a positive control) were used to simultaneously amplify all three gene products from leukocyte DNA from 416 normal healthy human volunteers. Identical GSTM1 and GSTT1 genotypes were obtained using nine samples processed either separately or simultaneously for GSTM1 and GSTT1. The frequency of the null genotype for GSTM1 was higher in whites (114/213 or 53.5% vs 56/203 or 27.6%, p