Identification of a deletion variant in the gene encoding the human alpha(2A)-adrenergic receptor.

Objective: The a2-adrenergic receptors are involved in the effects of catecholamines on energy metabolism. Of three known subtypes with differential expression, a2A-adrenergic receptors are also localized in adipose tissue where they counteract the lipolytic activity of b-adrenergic receptors. This study was undertaken to assess whether variants in the a2A-adrenergic receptor gene are associated with body weight. Design and methods: Single strand conformation polymorphism (SSCP) screening and subsequent sequencing were applied to determine genetic variants in DNA samples from individuals with obesity, those of normal weight and those underweight. Results: Analysis of the coding region resulted in the identification of an 18 bp deletion, with no other mutation found. Of 429 genotyped subjects, 7 carried the deletion, with no significant differences between lean and obese subjects. A previously identified polymorphism in the promoter of the a2Aadrenergic receptor gene also did not show an association with any of the tested body weight categories. Conclusion: Our data suggest that variants in the a2A-adrenergic receptor gene are unlikely to contribute to the predisposition for the lean or obese state.