Aim: to identify patterns of development of idiopathic dilated cardiomyopathy (IDC) and ischemic cardiomyopathy (ICM) by studying the rs 1801252 (Ser49Gly) polymorphic variant of the ADRB1 gene.Patients and Methods: a cohort of 221 patients (mean age — 55.30±9.69 years) was examined. All respondents underwent a standard set of laboratory and instrumental examinations, including coronary angiography. The first group included 111 patients with IDC, 99 of them (89.2%) were men, who were excluded from probable factors of dilated cardiomyopathy. The second group included 110 patients with IDC, including 100 (91.5%) men who had reliable signs of CHD. The control group included 221 people (mean age — 53.6±4.8 years) without signs of cardiovascular diseases. A molecular genetic study of the rs 1801252 (Ser49Gly) polymorphism of the ADRB1 gene was performed in all patients and in the control group. Results: among patients with IDC of both gender, 70.3% were carriers of the common homozygous A145A genotype, 27.0% of the heterozygous A145G genotype, and 2.7% of the rare homozygous G145G genotype. In the control group, there was also a predominant number of patients who carried the homozygous genotype for the common A145A allele — 71.9%. Carriers of the heterozygous A145G genotype were 25.3%, and the homozygous G145G genotype for a rare allele — 2.7%. The analysis of the genotypes frequency distribution of the polymorphic locus rs 1801252 (Ser49Gly) of the ADRB1 gene in patients with IDC and in the control group showed no differences. In the group of patients with ICM, the frequency of the common homozygous A145A genotype was 68.2%, there were fewer patients with the heterozygous A145G genotype — 29.1%, and the rare homozygous G145G genotype was detected in 2.7% of cases. There was no association with the ICM 1801252 (Ser49Gly) polymorphism of the ADRB1 gene in the group of patients with ICM, since the results of comparison with the control group data showed no statistically significant differences. At the same time, there were differences in the frequency of alleles of the polymorphic locus rs1801252 (Ser49Gly) of the ADRB1 gene: in male patients with IDC and ICM, the 145A allele was statistically significantly more common (p=0.0001) than in the control group.Conclusion: the data obtained suggest that the carrier of the 145A allele of the ADRB1 gene may serve as an additional risk factor for the development of dilated cardiomyopathy.KEYWORDS: dilated cardiomyopathy, ischemic cardiomyopathy, genetic polymorphism, β-1-adrenergic receptor gene, heart failure, genetic predisposition.FOR CITATION: Kuznetsova O.O., Nikulina S.Yu., Chernova A.A. et al. β-1-adrenoreceptor gene polymorphism role in the development of dilated cardiomyopathy. Russian Medical Inquiry. 2020;4(7):394–398. DOI: 10.32364/2587-6821-2020-4-7-394-398.