Human β 2 ‐adrenergic receptor polymorphisms: No association with essential hypertension in black or white Americans

Background and Objectives The most common polymorphisms of the human β 2 ‐adrenergic receptor‐Arg16→Gly and Gln27→Glu‐are associated with alterations in β 2 ‐adrenergic receptor responses, both in vitro and in vivo. β 2 ‐Adrenergic receptor–mediated vascular responses are affected by ethnicity, blood pressure, and genotype. We tested the hypothesis that these two common β 2 ‐adrenergic receptor genetic variants are associated with essential hypertension in black or white Americans. Subjects and Methods In a population‐based case‐control association study, the relationship between β 2 ‐adrenergic receptor genotypes and hypertension was examined in 307 normotensive subjects (128 black and 179 white) and 356 hypertensive subjects (155 black and 201 white). A polymerase chain reaction–based single‐stranded conformational polymorphism method with direct sequencing of the bands of interest was used to detect the two frequently occurring β 2 ‐adrenergic receptor variants (Arg16→Gly, Gln27→Glu). Results No significant differences in the distributions of alleles and genotypes of the tested β 2 ‐adrenergic receptor variants were found between normotensive and hypertensive groups from either black or white Americans (all P > .05). There was a marked interethnic difference in the frequency of the Gln27→Glu β 2 ‐adrenergic receptor polymorphism in both normotensive and hypertensive subjects. In normotensive white subjects, the variant Glu27 allele (35.2% versus 18.0%; P < .0001) and Glu27 homozygous genotype (14.0% versus 4.7%; P < .01) were more common than in black subjects. Similarly, in hypertensive white subjects, the variant Glu27 allele (35.8% versus 18.4%; P < .0001) and the Glu27 homozygous genotype (15.9% versus 2.6%; P < .0001) were more common than in black subjects. Conclusions These data suggest that although there are marked ethnic differences in their distribution, the common genetic polymorphisms of the human β 2 ‐adrenergic receptor gene do not cosegregate with the presence of hypertension in either black or white Americans. Clinical Pharmacology & Therapeutics (2000) 67 , 670–675; doi: 10.1067/mcp.2000.106293