Association of cytochrome P2D6 gene polymorphism with the susceptibility of Egyptian patients to systemic sclerosis disease

Abstract Background Systemic Sclerosis (SSc) is a chronic disease of the connective tissue caused by an autoimmune inflammatory process. Genetic polymorphisms of cytochrome P2D6 (CYP2D6) enzymes have been implicated in the SSc disease etiopathogenesis. Aim Our work was designed to investigate the association between the CYP2D6 gene mutation and the risk of SSc development and its relation to different SSc clinical manifestations. Methods One hundred SSc patients were involved in the study and one hundred healthy individuals were included to serve as a contol group. CYP2D6 *1, CYP2D6 *3, CYP2D6 *4 allelic frequencies were analyzed by the Polymerase Chain Reaction- Fragment Length Polymorphism (PCR-RFLP) method. Results The heterozygous extensive metabolizers (CYP2D6 *1/*4) genotype showed a statistically significant risk for developing SSc, assessed by the odds ratio (OR = 2.4, P = 0.003). The homozygous extensive metabolizers (CYP2D6 *1/*1) which are the wild genotypes, were expressed less frequently in SSc patients with a significant difference (OR = 0.23) in comparison with the control group. As for the alleles frequency, a significant increase in the risk of SSc was associated with the mutant CYP2D6 *4 allele frequency (OR = 2.2), indicating that the presence of allele CYP2D6*4 is a risky genetic factor for SSc. Diffuse type systemic sclerosis, gastrointestinal (GIT), cardiac, pulmonary manifestations, positive anti-scleroderma 70, moderate restriction in pulmonary function tests, and abnormal Echocardiographic findings were significantly associated with the (CYP2D6 *1/*4) genotype. Conclusion Finding of the study revealed a higher prevalence of the heterozygotes extensive metabolizers (CYP2D6 *1/*4)genotypes and the mutant alleles (CYP2D6*4) in SSc patients, suggesting the high impact of the CYP2D6 gene mutation on the SSc development.