G/A polymorphism in intronic sequence affects the processing of MAO-B gene in patients with Parkinson disease.

Monoamine oxidase B (MAO-B) plays an important role in the metabolism of neuroactive and vasoactive amines in the central nervous system and peripheral tissues. Increased levels of MAO-B mRNA and enzymatic activity have been reported in platelets from patients with Parkinson's and Alzheimer's diseases, however the triggers of enhanced mRNA levels are unknown. Our results demonstrate for the first time that G/A dimorphism in intron 13 sequence creates splicing enhancer thus stimulating intron 13 removal efficiency. The increased MAO-B protein levels might serve as a surrogate marker for - Parkinson disease.