Essential hypertension (EH) is a multifactorial disease with a hereditary predisposition. Genes encoding the renin-angiotensin system (RAS) play a leading role in the stabilization of elevated BP in the course of EH, which determines the relevance of our clinical and genetic study. The study was based on the determination of the frequencies of polymorphic markers of the AGT, AGTR1, ACE, ITGB3, PPARG genes in 2 groups, depending on the age of patients (up to 60 years - group1, n=18, and after 60 years - group2, n=31), for the intergroup frequencies comparison and comparison of group frequencies with population data. Genotyping by gene polymorphisms was performed by real-time polymerase chain reaction. 24-hour ambulatory BP monitoring (ABPM) and Holter HR monitoring were conducted. Phenotypic features of the course of EH were accompanied by changes in the frequency characteristics of the studied genotypes. In patients of group 1, an increase in the frequency of protective genotypes of the ACE(II) and ITGB3(TT) genes was observed (p=0.004;0.015), which confirms the hypothesis of a possible favorable course of EH in patients under 60 years. © This article is published under the terms of the Creative Commons Attribution License 4.0 https://creativecommons.org/licenses/by/4.0/deed.en_US