The α_2CDel322-325 adrenergic receptor polymorphism is not associated with heart failure due to idiopathic dilated cardiomyopathy in black Africans

Background: A four-amino acid deletion was identified within the α_2C-adrenergic receptor (α_2CDel322-325) that, when homozygous, increases the risk of heart failure in African-Americans nearly six-fold. We hypothesised that homozygosity for the α_2CDel322- 325 polymorphism may be a risk factor for heart failure due to idiopathic dilated cardiomyopathy (DCM) in black South Africans. Methods: The α_2CDel322-325 polymorphism was genotyped in 37 patients with heart failure and 34 controls, all of black African ancestry. Genotyping was performed by a size-fractionation assay. Results: The patients studied ranged in age from 21 to 79 years with a mean age of 50 years, and 62% were male. No significant difference was observed in homozygosity for the α _2CDel322-325 polymorphism or in allele and genotype frequencies between patients and controls. The frequency of the allele containing the deletion was 0.54 in cases and 0.53 in controls. The genotype frequencies in the patients were consistent with those of the controls (p = 0.56). Conclusions: Homozygosity for the α_2CDel322-325 polymorphism is not associated with an increased risk for heart failure due to idiopathic DCM in black South Africans.