Association between the angiotensin-converting enzyme gene insertion/deletion polymorphism and the risk for psoriasis

Background Genetic polymorphisms and environmental factors such as treatment with angiotensin-converting enzyme (ACE) inhibitors have been suggested to play a role in the pathogenesis of psoriasis. An insertion/deletion (I/D) polymorphism of the ACE gene affects ACE activities. Objective To investigate the association between the ACE gene I/D polymorphism and the development of psoriasis. Patients and methods Thirty patients with plaque-type psoriasis and 20 age-matched and sex-matched healthy volunteers were included in this study. All participants were analyzed for the ACE gene I/D polymorphism by PCR. Results No significant difference was found in the frequencies of ACE I/D alleles between patients and control participants (P= 0.870). However, the frequency of the I allele was found to be statistically significantly higher in patients with familial psoriasis (83.3%) versus those with a negative family history (43.8%) (P = 0.014). No significant difference was also found in the ACE genotype frequencies between patients and control participants (P= 0.961). On comparing the extent of the disease and the Psoriasis area and severity index (PASI) score in relation to the ACE genotypes within the patient group, we found statistically significant extensive disease and a higher PASI score in association with the DD genotype (P= 0.005 and 0.023, respectively). Conclusion ACE polymorphism is not likely to be associated with Egyptian psoriatic patients in this pilot study; however, the presence of the I allele may lead to susceptibility to develop psoriasis in individuals from psoriatic families and homozygosity for the ACE D allele may affect susceptibility to develop severe psoriasis.