PRKN and Parkinsonism: Degos et al. (108) studied visual saccades initiated after variable foreperiods before movement in PD (both ON and OFF meds) and PARKIN-associated parkinsonism (the PARKIN gene, also known as PRKN, encodes an ubiquitin ligase; various mutations of the gene have been associated with an autosomal recessive parkinsonism, typically of juvenile onset).