GSTM1, GSTT1 and EPHX1 gene polymorphisms and susceptibility to COPD in a sample of Egyptian population

Background: Gene polymorphisms and COPD susceptibility have been paid special attention and were explored in a large number of studies. The results varied between studies and populations. We aimed to analyze the relation between susceptibility to COPD and polymorphisms of Glutathione S-transferases (GST); GSTM1, GSTT1 and Microsomal epoxide hydrolase-1 (EPHX1) genes in a sample of Egyptian population. Methods: Genetic polymorphisms of GSTM1, GSTT1 and EPHX1 genes in 146 COPD patients and 130 controls were investigated using multiplex PCR for GSTM1 and GSTT1 genes and PCR-RFLP for EPHX1 genes. Results: The frequency of GSTM1-null genotype was higher in patients than in controls (72.6% versus 43.8%, P < 0.001). Carriers with both null GSTT1 and GSTM1 genes were at a higher risk of COPD (OR 3.45, 95% CI = 1.07-11.14). The frequency of EPHX1 exon 3 His allele was higher in patients than controls (19.2% versus 12.7%, P = 0.04). Carriers with exon 3 His allele were at a higher risk of COPD (OR 1.63, 95% CI = 1.02-2.6, P = 0.04). Carriers with both GSTM1-null and EPHX1 113Tyr/Tyr or EPHX1 113Tyr/His genotypes were at a higher risk of COPD (OR 3.33, 95% CI = 1.32-8.35 and OR 14.24, 95% CI = 3.02-67.17 respectively). Carriers with both GSTM1-null and EPHX1 139His/His genotypes were at a higher risk of COPD (OR 5.58, 95% CI= 2.14-14.52). Conclusions: EPHX1 exon 3 His allele in addition to the coexistence of other genetic variants, were significant risk factors in susceptibility to COPD in the Egyptian population. (C) 2015 The Authors. Production and hosting by Elsevier B.V. on behalf of The Egyptian Society of Chest Diseases and Tuberculosis.