Manganese-Induced Parkinsonism And Mitochondrial DNA Partly Mutations

Objective: To investigate the relationship between manganese-induced parkinsonism and mitochondrial DNA(mtDNA)partly mutations.Methods: Eighteen patients with manganese-induced parkinsonism and thirty-five patients who have also the same age and work environment as the manganism patients but did not diagnose as manganese-induced parkinsonism and forty healthy controls were enrolled in this study. Polymerase chain reaction (PCR) was used to amplify three mtDNA segments of all participants, including mtDNA 8344, mtDNA 11778 and mtDNA 12S rRNA gene region. For the PCR products of mtDNA point 8344, 11778 and 12SrRNA gene region, single strand conformation polymorphism (SSCP) was adopted to detect mutations and the abnormal segments were sequenced. SPSS 13.0 statistics software was used to analysis the results.Results: The mtDNA 9-bp deletion was identified in twenty-two participants. Besides, we also found two new mtDNA point mutations in this study which have never been reported in previous literature available. The first one is mtDNA point 8175 G>A mutation which was detected in four manganese-induced parkinsonism patients; the second one is mtDNA point 11914 G>A mutation which was found in three manganese-induced parkinsonism patients. However, we have not found any mutations among mtDNA 8344, 11778 and 12SrRNA gene region.Conclusion: The frequency of mtDNA 9-bp deletion of Guangxi people was significantly higher than the average of the country. The mtDNA point 8175 G>A mutation and point 11914 G>A mutation may be associated with susceptibility to chronic manganism or may be involved in the pathogenesis of manganese-induced parkinsonism,but this should be confirmed by future large sample and well designed study. MtDNA point 8344, 11778 and 12SrRNA gene region may be not a mutational hot spot or region in the pathogenesis of manganese-induced parkinsonism.