Interaction between α-synuclein and tau genotypes and the progression of Parkinson's disease

Objective: To determine whether α-synuclein NACP-Rep1 and tau genotypes can predict the rate of progression of Parkinson's disease. Methods: 123 Parkinson's disease cases were recruited for neurological examination and DNA donation. The rate of progression was assessed as the motor Unified Parkinson's disease Rating Score divided by symptom duration at the time of assessment and associations determined with α-synuclein NACP-Rep1 and tau genotypes. Results: There was a significant effect of genotype on the rate of progression of Parkinson's disease. In MAPT H2 haplotype carriers, some NACP-Rep1 genotypes, thought to be associated with increasing α-synuclein expression, were linked with a higher rate of progression. In NACP-Rep1 0/0 genotype carriers, patients without MAPT H2 haplotype had a higher rate of progression of Parkinson's disease. The relative risk to develop a more rapid disease progression in these genotypes reached 5.8. Conclusion: Genetic factors not only influence the risk of Parkinson's disease, but also the progression of Parkinson's disease.