Whereas clinical characterization of patients carrying NCL-/AD-associated CTSD mutations are available (Riemenschneider et al., 2006; Siintola et al., 2006; Steinfeld et al., 2006; Fritchie et al., 2009; Ehling et al., 2013; Hersheson et al., 2014), there is no clinical data on the here analyzed PD-associated CTSD variants, as they were found in a large genetic-meta analysis (Robak et al., 2017). Here, CTSD is linked to Parkinson disease.