Study to Determine Mutations in the Gaucher Gene in Patients With Idiopathic Parkinson's Disease for Phenotype-genotype Correlation

The genotype-phenotype correlation in patients with Parkinson's disease with specific mutations in the glucocerebrosidase gene (Gaucher gene) is known from own clinical experiences as well as from case reports in the literature. The epidemiological study will determine the frequency of heterozygous mutations in the glucocerebrosidase gene and correlate to the clinical onset and development by measuring and documenting severity of symptoms (e.g. cognitive deficits, L-dopa responsiveness, depression) in clinically well-characterized Parkinson's patients.