1. ¹Pain and Neurosensory Mechanisms Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, USA
2. ²Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, USA

Correspondence: Dr Inna Belfer, National Institutes of Health, 12420 Parklawn Drive, Suite 451, MSC 8110, Rockville, MD 20852, USA. Tel: +1 301 402 8323; Fax: +1 301 443 8579; E-mail: ibelfer@mail.nih.gov

Received 16 March 2004; Revised 23 July 2004; Accepted 27 August 2004; Published online 3 November 2004.

Abstract

The beta-adrenergic receptors (-AR) are G protein-coupled receptors activated by epinephrine and norepinephrine and are involved in a variety of their physiological functions. Previously, three -AR genes (ADRB1, ADRB2 and ADRB3) were resequenced, identifying polymorphisms that were used in genetic association studies of cardiovascular and metabolic disorders. These studies have produced intriguing but inconsistent results, potentially because the known functional variants: ADRB1 Arg389Gly and Gly49Ser, ADRB2 Arg16Gly and Gln27Glu, and ADRB3 Arg64Trp provided an incomplete picture of the total functional diversity at these genes. Therefore, we created marker panels for each -AR gene that included the known functional markers and also other markers evenly spaced and with sufficient density to identify haplotype block structure and to maximize haplotype diversity. A total of 27 markers were genotyped in 96 US Caucasians and 96 African Americans. In both populations and for each gene, a single block with little evidence of historical recombination was observed. For each gene, haplotype captured most of the information content of each functional locus, even if that locus was not genotyped, and presumably haplotype would capture the signal from unknown functional loci whose alleles are of moderate abundance. This study demonstrates the utility of using -AR gene haplotype maps and marker panels as tools for linkage studies on -AR function.