Arg389Gly β1-adrenoceptor polymorphism varies in frequency among different ethnic groups but does not alter response in vivo

There are marked interethnic differences in beta (1)-adrenclceptor-mediated responsiveness, with sensitivity decreased in African-Americans and increased in Chinese compared with Caucasians, Therefore, the frequency of a common naturally occurring polymorphism of the human beta (1)-adrenoceptor gene (Arg(389)Gly), which has functional importance in vitro, was determined in 194 African-Americans, 316 Caucasian-Americans, 221 Hispanic-Americans and 142 Chinese. African-Americans were found to hare a significantly lower frequency of the Arg(389) allele than the other three ethnic groups (all P < 0.01), In the populations studied, the order of the distribution of the Arg(389) allele was: Chinese (74%) > Caucasians (72%) > Hispanics (67%) > African-Americans (58%). To determine the functional significance of the Arg(389)Gly beta (1)-adrenoceptsr polymorphism in-vivo heart rate responses to exercise were compared in healthy subjects homozygous for the Arg (n = 9) and Gly (n = 8) alleles, Heart rate response to exercise was not affected by genotype (P = 0.4). Although ethnic differences in the frequency of the beta (1)-adrenoceptor Arg(389)Gly polymorphism exist, the polymorphism does Hot appear to have functional significance in healthy subjects and therefore may not contribute to ethnic differences in response to drugs acting through the beta (1)-adrenoceptor, Pharmacogenetics 11:191-197 (C); 2001 Lippincott Williams & Wilkins.