and CAG triplet repeat sizes: exploring their role in the disease risk and cancer comorbidity in Parkinson's disease.

Parkinson's disease genetic embraces genetic and non-genetic factors. It has been suggested a link between CAG repeat number in the and genes and different neurodegenerative diseases. Several genetic factors involved in Parkinson's disease development are indeed associated with cancer pathways. Moreover, several studies found a low prevalence of cancer in neurodegenerative diseases that can be associated with a low CAG repeat size in several genes. This study aimed to investigate the influence of CAG repeat sizes in and genes on the risk for developing cancer and Parkinson's disease in a large cohort of patients with idiopathic Parkinson's disease and healthy controls. The work included 1052 patients with idiopathic Parkinson's disease and 1070 controls of European ancestry. CAG repeat sizes in and 2 genes were analysed. Dunn's multiple comparison test for quantitative variables and logistic and linear regression were used. The long and alleles and CAG size and both the short and long alleles were predictors for the Parkinson's disease risk. The long CAG allele gene was associated with the risk of cancer. No association was observed between CAG size in the and genes and risk of cancer in patients with Parkinson's disease. We described an association of and with the risk of Parkinson's disease, which reinforce the hypothesis of the common pathway of neurodegeneration. Besides, could be a predictor of cancer risk among patients with Parkinson's disease, and these results suggest that cancer and neurodegeneration processes can share common pathways.