Genetic polymorphism of monoamine oxidase B and susceptibility of Parkinson's disease.

BACKGROUND: Monoamine oxidase B (MAO-B) may play a role in the progression and cause of Parkinson's disease (PD), given consideration of the biochemistry and pathophysiology of the disease, and experiments on primates and humans. Assuming that the structural gene determines enzyme activity, an association study was undertaken to examine MAO-B genetic polymorphisms and look for the unique MAO-B gene alleles which occurred at a higher frequency in PD patients. METHODS: Sixty-five PD patients, diagnosed according to the criteria set by a Core Assessment Program for Intracerebral Transplantations Committee, and 108 healthy controls were enrolled in this study. Genomic DNA was extracted from peripheral leukocytes by using a puregene kit. Polymerase chain reaction (PCR) was used to amplify the MAO-B genome. The PCR products were screened by restriction enzyme Hae III digestion and analyzed by single-stranded conformational polymorphism (SSCP). RESULTS: Two bands with different mobility shifts, defined as MAO-B allele 1 and allele 2, were observed in SSCP analysis. Neither genotypes nor allelic frequencies of MAO-B showed a significant difference between PD patients and controls in our study. CONCLUSIONS: Polymorphism of MAO-B genome was demonstrated in this study. It failed to show an association of a genetic marker with PD. However, this did not necessarily exclude the MAO-B locus from playing a role in causing PD because a polymorphism different from the one evaluated here may show some disease association.