Figure 2 Age at onset of Parkinson disease as a function of number of PARK2 mutations

Patients with 2 (long dashed line), 1 (short dashed line), and 0 (solid line) PARK2 mutations. Rare nonsynonymous sequence variants were considered to be a mutation only when found in an individual carrying a copy number variation (CNV). Age at onset in heterozygous PARK2 patients is not earlier than in patients lacking a PARK2 CNV mutation, as opposed to patients with compound mutations who have substantially earlier onset. The graph was generated using Kaplan-Meier survival analysis and the differences were tested using log-rank statistics. Overall, p = 1 × 10⁻⁴⁰, which is driven by compound mutation carriers in recessive young-onset disease.