Neurodegenerative diseases (NDs) have increasingly been linked to dysfunction of specific proteins, often unique to one disease, e.g. amyloid precursor protein (APP) to Alzheimer's disease (AD), parkin (Park) to Parkinson's disease (PD), huntingtin (HTT) to Huntington's disease (HD), and superoxide dismutase (SOD1) to amyotrophic lateral sclerosis (ALS) (Kaur et al., 2016; Lill, 2016; Nopoulos, 2016; Selkoe and Hardy, 2016). This evidence concerns the gene HTT and Parkinson disease.