Study of Angiotensin Converting Enzyme gene insertion/deletion polymorphism, rs4340 in an urban Indian cohort, South Mumbai

Abstract

The insertion/deletion polymorphism (rs4340) of the Angiotensin Converting Enzyme (ACE) gene has been considered as a genetic risk factor for cardiovascular disease. The present cross sectional study aimed to evaluate the ACE gene insertion/deletion polymorphism in a cohort of urban residents from Mumbai, India. A total of 190 unrelated subjects, aged 15-93 years, attending Bay View Clinic participated in the study. Metabolic variables including blood pressure and blood glucose levels were measured. The ‘I/D’ polymorphism, rs4340 was determined by polymerase chain reaction, PCR followed by agarose gel electrophoresis. The ‘I/D’ genotype in heterozygotes was confirmed by a second PCR using insertion-specific primers. Among the study cohort, 70 subjects (36.8%) had metabolic disorders.The allele frequency was found to be as 0.61 for the ‘I’ allele and 0.39 for the ‘D’ allele. The distribution of I/I, I/D and D/D genotype was 37.4%, 47.9% and 14.7%, respectively. People in the age group of 46-55 years had high distribution of ‘I/I’ genotype (52.4%). Study subjectsin the younger age group of 15-24 years had the highest frequency of 21.8% for the ‘D/D’ genotype, considered as a high risk genotype. In the present study, ‘D/D’ genotype was associated with higher body mass index and lower age even in the absence of established cardiovascular risk factors. Obesity was more prevalent in women (66.6%) as compared to men (33.4%). In conclusion, we found ‘I/D’ heterozygosity of the polymorphism,rs4340 as the most common genotype among this hospital cohort, with a slight over representation of ‘D’ allele among obese and overweight subjects.