Aims: The adrenergic nervous system is of major importance in congestive heart failure. No genetic polymorphism has previously been identified in the beta(1)-adrenergic receptor gene. The aim of this study was to find possible mutations in this gene and to relate such findings to morbidity and prognosis in heart failure.
Methods and results: Genomic DNA was extracted from blood leukocytes from patients with congestive heart failure (n=184) and from age-matched controls (n=77). The part of the beta(1)-adrenergic receptor gene corresponding to nucleotide 1-255 was amplified by polymerase chain reaction and analysed by automated sequencing. The patients were investigated by echocardiography and followed regarding symptoms and survival for 5 years. A missense mutation was identified at nucleotide position 145 in the beta(1)-adrenergic receptor gene, which predicted an amino acid substitution at position 49 (Ser49Gly). The allele frequency of the Gly49 variant was 0.13 in controls and 0.18 in patients (P=0.19). At the time of the 5-years follow-up, 62% of the patients with the wild type gene and 39% of the patients with the Ser49Gly variant had died or had experienced hospitalization (P=0.005). Patients without the mutation had significantly poorer survival compared to those with the mutation, risk ratio 2.34 (95% CI 1.30-4.20), P=0.003. In a mulivariate analysis, the risk ratio was 2.03 (95% CI 0.99-4.16) P=0.05.
Conclusion: A novel missense mution in the beta(1)-adrenergic receptor gene was associated with a decreased mortality risk in patients with congestive heart failure. These data suggest that the beta(1)-receptor Ser49Gly variant might be associated with altered receptor function, resulting in myocardial protection in patients with heart failure.
Copyright 2000 The European Society of Cardiology.