[Polymorphism of vascular angiotensin II receptor gene and cardiovascular disorders]

To study polymorphism of the gene of vascular angiotensin II receptor.

Polymorphism that consists in variability of adenine (A) and cytosine (C) residues at position 1166 of the gene for vascular angiotensin II receptor (AT1R) was analyzed in a Moscow population (n = 98) and three groups of affected patients with myocardial infarction (n = 32, MI), left ventricular hypertrophy (LVH, n = 38) and essential hypertension (EH, n = 178). Polymorphic region of the AT1R gene was amplified using the polymerase chain reaction (PCR) and genomic DNAs from human whole blood as template. PCR products were electrophoresied in a gel after digestion with BstDEI restriction nuclease. Significance of differences in distribution of both allele and genotype frequencies at the population sample and in affected patients were estimated via exact Fisher's test.

A significant decrease in the frequency of the A genotype was detected in all the three affected groups compared to healthy controls. Besides, the frequency of the A allele was significantly decreased in EH group with a corresponding increase in the frequency of both the AC genotype and the C allele.

The A1166C polymorphism of the AT1R gene is associated with EH, MI and LVH in a Moscow population. The association is stronger with EH. The A allele and the AA genotype protect against development of disorders at early onset while the other genotypes and the C-allele are risk factors. A protective role of the AA genotype is more significant than predisposition action of the CC homozygote.