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

Abstract

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.

Keywords

• COPD
• Genetic susceptibility
• Polymorphisms
• Glutathione S-transferase
• Microsomal epoxide hydrolase