Polymorphisms of the beta-1 and beta-2 adrenergic receptors in Polish patients with idiopathic dilated cardiomyopathy.

Background: Dilated cardiomyopathy (DCM) is a disorder characterised by dilation and impaired contractility of the left or both ventricles. This multifactorial disease has a strong genetic component with familial occurrence. A number of genes have been associated with idiopathic DCM (IDCM) including beta-1 (b1-AR) and beta-2 (b2-AR) adrenergic receptors. b1-AR and b2-AR are G-coupled proteins which play an important role in the regulation of heart rate and cardiac contractility. The beta-adrenergic receptor pathway is altered in heart failure. Recent studies have discovered functionally relevant and common polymorphisms in both b1-AR and b2-AR.

Aim: We investigated the frequency of the b1-AR (Ser49Gly, Arg389Gly) and b2-AR (Arg16Gly, Gln27Glu, Thr164Ile) polymorphisms in patients with IDCM in comparison to controls in the Polish population.

Methods: We used a case-control study design comparing a series of consecutive, unrelated 97 IDCM patients with 105 healthy blood donors. Polymorphisms were determined by polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP).

Results: There was no significant difference in relation to genotype distribution and allele frequencies of any analysed b1-AR and b2-AR polymorphisms between IDCM patients and controls. The analysis of polymorphism associations did not reveal a higher frequency of coexisting b2-AR Gly16Gln27, Gly16Glu27 and Arg16Gln27 genotypes alone or in combination with the b1-AR Arg389 allele in IDCM.

Conclusion: Our data showed that the studied beta-adrenergic receptor polymorphisms did not seem to play a significant role in IDCM in the Polish population.