Angiotensin-converting enzyme gene insertion/deletion (I/D) polymorphism in Azerbaijan population

Angiotensin-converting enzyme (ACE) is a key enzyme of the renin-angiotensin-aldosterone system (RAAS), which is directly involved in the regulation of blood pressure. It is assumed that the insertion/deletion (I/D) polymorphism of the gene of this enzyme (ACE gene) appears due to the presence/absence of ~ 287 bp Alu repeats in the 16 intron and is associated with the risk of the development of some diseases, including cardiovascular diseases, various kinds of mental disorders, Alzheimer's disease, gestational diabetes, etc. Given the lack of data on ACE gene I/D polymorphism for the Azerbaijan population, we studied polymorphism of this gene by PCR, using sequence specific pairs of primers (Hace3s and Hace3as (I), ACE-F and ACE-R (II)). DNA samples isolated from 346 individuals were divided into 4 groups: (1) patients with various mental disorders (90 patients); (2) a group of young students involved in various sports (84 male persons); (3) patients with diabetes (28 patients with I type DM (3A subgroup) and 72 patients with II type DM (3B subgroup); (4) a group of conditionally healthy people of different ages and specialties (72 persons, control). Based on the results of PCR of both primer pairs, the following genotypes were obtained: 16 individuals with genotype II (4.6%, homozygous co-dominants for the I-allele), 101 individuals with genotype DD (29.2%, homozygous co-dominants for the D-allele) and 228 individuals with genotype ID (66.2%, heterozygotes for both alleles). The frequency of occurrence was: fI=0.373, fD=0.627, ND:NI=1.681. The ratio of separate genotypes within the studied population: ID:DD=2.173; ID:II=14.125; DD:II=6.500. Comparison of the values of the dominant model for the allele D (DD+ID)/II=20.625 and the recessive model DD/(ID+II)=0.430 relative to the dominant model for the allele I (II+ID)/DD=1.152 and the recessive model II/(ID+DD)=0.048 indicates that in both models the probability of the D allele to associate with any particular trait is higher than that of the I allele (17.904 and 8.958 times, respectively). These results confirm the literature data on the association of the D allele with many pathologies or diseases. The analysis of the obtained data also revealed a significant correlation (p≤0.01) of the studied features from the D allele both within groups and between groups.