Several recent studies identified RAB32 p.R71R as a susceptibility variant for familial PD29–31 and also reported additional variants in other genes with strong associations with PD.31 Interestingly, among them was a rare missense variant in the PPM1M gene: NM_144641.4: c.1318G>A p.D440N (hereafter referred to as D440N). Here, PPM1M is linked to Parkinson disease.