Genotype and allele frequencies of MDR-1, TPMT, NAT2, GST and SULT1A1 in the Sudanese and Bahraini population

Abstract

The goal of this study was to determine the frequencies of important allelic variants in the TPMT, NAT2, GST, SULT1A1and MDR-1 genes in the Sudanese and Bahraini population and compare them with the frequencies in other ethnic populations. Genotyping was carried out in a total of 300 unrelated Bahraini and 142 unrelated Sudanese subjects.TPMT*2 was detected using an allele-specific polymerase chain reaction (PCR) assay.TPMT*3C and NAT2 variants (*5, *6 and *7) were detected using an allele specific real-time PCR assay. Detection of GSTM1and GSTT1 null alleles was performed simultaneously using a multiplex PCR assay. Finally, a PCR-restriction fragment length polymorphism assay was applied for the determination of TPMT*3A(*3B), SULT1A1*2 and MDR-1(3435T) variants. Genotyping of TPMT revealed frequencies of (0.0) and (0.0) for TPMT*3A and TPMT*3C for Sudanese, and frequencies of (0.0) and 0.036 for Bahraini, respectively. No TPMT*2 or *3B was detected in the analyzed samples. The frequencies of specific NAT2 alleles were 0.1, 0.569, 0.288 and 0.044 for *4 (wild-type), *5 (341C), *6 (590A) and *7 (857A), for Sudanese , and 0.15 ,0.405 ,0.397 ,0.047 for Bahraini respectively. GSTM1 and GSTT1null alleles were detected in 54.4% and 42.0% for Sudanese, 49.7% and 28.7% for Bahraini, respectively.SULT1A1*2were detected at a frequency of 0.26 for Sudanese and 0.42 for Bahraini. Finally, the frequencies of the wild-type allele (3435C) and the (3435T) variant in the MDR-1gene were found to be 0.74 and 0.24 for Sudanese 0.58 and 0.42 for Bahraini, respectively. We found that Bahraini population more closely resemble Caucasians and Sudanese population more closely resemble African. The purpose of our future studies is to investigate for new polymorphisms, which could be relatively unique to the Bahraini and Sudanese population.