A MULTIPLEX PCR PROCEDURE FOR POLYMORPHIC ANALYSIS OF GSTM1 AND GSTT1GENES IN POPULATION STUDIES

A deletion polymorphism in glutathione S-transferase theta (GSTT1) gen e was recently discovered in humans. Similar to the GSTM1 gene, GSTT1 is also recognized as a risk modifier in exposed populations. To evalu ate the role of genetic poly morphism in health effects, the combined genetic polymorphism of different genes should be taken into considera tion. In the present study, we have developed a multiplex PCR approach for simultaneous replication of both genes for molecular analysis. Th e multiplex PCR protocol was validated using donor DNA with different polymorphic combinations for both genes from two different ethnic popu lations (North Americans and Egyptians). The prevalence of the GSTM1 n ull genotype was 51% among North Americans and 44% among Egyptians. Th e prevalence of the GSTT1 null genotype was 15% among North Americans and 14.7% among Egyptians. Combined polymorphism analysis of both gene s revealed that 6.3% of North Americans harbor the deleted genotype of both genes compared to 8.8% of the Egyptians. The data indicate that there is no major difference in allelic distribution of both genes bet ween the ethnic populations. The multiplex PCR assay used in this stud y has the advantage of reducing the time, effort and cost required to carry out such analysis. It will also significantly enhance the abilit y to use genetic screening techniques as a potential tool for early de tection of health outcomes in exposed populations.