The sparteine/debrisoquine (CYP2D6) oxidation polymorphism and the risk ofParkinson's disease: a meta-analysis

The association between the sparteine/debrisoquine (CYP2D6) oxidation polym orphism and the risk of Parkinson's disease was examined in a meta-analysis of case-control studies. The odds ratio was calculated for the risk of Par kinson's disease among poor metabolisers compared with extensive metabolise rs. Twenty-one studies were identified of which six were excluded because t hey were not reported as full papers (n = 3), used incomplete genotype anal ysis (n = 2) or used Parkinson patients as both control individuals and cas es (n = 1). The overall odds ratio was 1.48 (95% confidence interval 1.10-1 .99). The odds ratio was 1.05 (95% confidence interval 0.63-1.77) in studie s discriminating extensive and poor metabolisers by phenotyping (n = 8) and 1.67 (95% confidence interval 1.11-2.50) in studies using genotyping (n = 7). This difference was caused by a single large study using genotyping. We conclude that there is no convincing evidence of an association between th e debrisoquine/sparteine polymorphism and Parkinson's disease. However, it could prove worthwhile to perform another large study using genotyping. Pha rmacogenetics 8:473-479. (C) 1998 Lippincott Williams & Wilkins.