The EcoRV genetic polymorphism of human monoamine oxidase type A is not associated with Parkinson's disease and does not modify the effect of smokingon Parkinson's disease

We previously observed an association with Parkinson's (PD), and modificati on of the effect of smoking on PD, by a polymorphism of the monoamine oxida se B (MAO-B) gene. The A form of monoamine oxidase (MAO-A) shares with MAO- B many characteristics that could be relevant to PD, especially proneuroxic ant bioactivation and dopamine metabolism. MAO-A is also inhibited by tobac co smoke, which bears an apparent protective effect on PD. We investigated the possibility that MAO-A genetic variants may also be involved in predisp osition to PD and in modification of the effect of smoking. Three-hundred a nd seventy-one subjects - 145 idiopathic PD cases and 226 age/gender-matche d controls - were genotyped for the EcoRV polymorphism of MAO-A gene which has been related to increased enzyme activity. MAO-A EcoRV polymorphism was neither significantly associated with PD nor did it modify the inverse rel ationship with smoking. These results suggest that the EcoRV polymorphism o f MAO-A is not an important biomarker of PD risk. Published by Elsevier Sci ence Ireland Ltd.