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

AIMS: The goal of this study was to determine the frequencies of important allelic variants in the TPMT, NAT2, GST, SULT1A1 and MDR-1 genes in the Egyptian population and compare them with the frequencies in other ethnic populations. METHODS: Genotyping was carried out in a total of 200 unrelated Egyptian 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 GSTM1 and 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. RESULTS: Genotyping of TPMT revealed frequencies of 0.003 and 0.013 for TPMT*3A and TPMT*3C, respectively. No TPMT*2 or *3B was detected in the analysed samples. The frequencies of specific NAT2 alleles were 0.215, 0.497, 0.260 and 0.028 for *4 (wild-type), *5 (341C), *6 (590A) and *7 (857A), respectively. GSTM1 and GSTT1 null alleles were detected in 55.5% and 29.5% of the subjects, respectively. SULT1A1*2 was detected at a frequency of 0.135. Finally, the frequencies of the wild-type allele (3435C) and the 3435T variant in the MDR-1 gene were found to be 0.6 and 0.4, respectively. CONCLUSIONS: We found that Egyptians resemble other Caucasians with regard to allelic frequencies of the tested variants of NAT2, GST and MDR-1. By contrast, this Egyptian population more closely resemble Africans with respect to the TPMT*3C allele, and shows a distinctly different frequency with regard to the SULT1A1*2 variant. The predominance of the slow acetylator genotype in the present study (60.50%) could not confirm a previously reported higher frequency of the slow acetylator phenotype in Egyptians (92.00%), indicating the possibility of the presence of other mutations not detectable as T341C, G590A and G857A. The purpose of our future studies is to investigate for new polymorphisms, which could be relatively unique to the Egyptian population.

Genotyping of four genetic polymorphisms in the CYP1A2 gene in the Egyptian population.

AIMS: The goal of this study was to determine the frequencies of CYP1A2*1C, *1D, *1E and *1F variants in the Egyptian population and compare frequencies with other populations. METHODS: Genotyping was performed in a total of 212 unrelated Egyptian subjects using polymerase chain reaction-restriction fragment length polymorphism assay. RESULTS: The frequencies of CYP1A2*1C, *1D, *1E and *1F variants in the Egyptian population were 0.07, 0.40, 0.03 and 0.68, respectively. The Egyptians have a lower frequency of CYP1A2*1C, and CYP1A2*1E than the Japanese (0.07 vs 0.21 and 0.03 vs 0.08, respectively), while the frequencies of CYP1A2*1D and CYP1A2*1F did not differ significantly between the two groups. CYP1A2*1F (0.68) frequency in Egyptians was identical to that observed in Caucasians (0.68 among 236 German individuals). CONCLUSIONS: The present study is the first to describe the frequencies of four known allelic variants of CYP1A2 among the Egyptian population. CYP1A2*1C and *1E occurred at frequencies significantly lower than that in Japanese, while similar frequencies were observed for CYP1A2*1D and *1F. The CYP1A2*1F frequency appeared to be identical to that of Caucasians. This does not exclude the possibility of the presence of new mutations relatively specific to the Egyptian population that have not been identified.