PRKN and Parkinson disease: Nineteen kindreds were chosen for parkin analysis based on having parkinsonism in two consecutive generations, late-onset parkinsonism in the parent generation (onset ages 59 to 89 years, mean 71.0 ± 8.5), early-onset parkinsonism in the offspring generation (onset ages 8 to 47 years, mean 37.2 ± 9.8), and ≥ 20 years of anticipation as measured by the difference in mean ages at onset in two generations.