Association of Glutathione-S-Transferase P1 (GSTP1) and Group-Specific Component (GC) Polymorphism with the Risk of Asthma in Pakistani Population

Risk of asthma is associated with complex interplay of genetic, ethnic and environmental factors therefore asthma prevalence in various ethnic groups cannot be predicted from the interethnic genotype and allelic frequencies. Currently there is very limited data available regarding the association of genetic polymorphisms with asthma in Pakistani population. The following study was aimed to assess the association of glutathione-S-transferase P1 (GSTP1) and group-specific component (GC) with asthma in adult Pakistani population. Genetically unrelated and clinically diagnosed 200 asthmatics along with 200 healthy controls were voluntarily recruited for this study. Genotyping was performed using conventional PCR. GSTP1 and GC polymorphisms were determined by using restriction fragment length polymorphism (RFLP) technique. The homozygous GSTP1 Ile/Ile genotype was found to be significantly associated (p = 0.003) with the risk of asthma whereas the homozygous GSTP1 Val/Val genotype (p = 0.19) was found to be more frequent in control population than in the patients (6% and 10%, respectively). The GC polymorphism GC2 homozygote was also significantly associated with the risk of asthma (p = <0.001), whereas the GC1S homozygote (p = 0.250) was less frequent in asthmatics and more prevalent in the control group (3.5% and 6.5%, respectively). It is thus concluded that the polymorphisms in both the GSTP1 and GC are significantly associated with the risk of asthma in Pakistani population.