At least 23 loci and 13 genes clearly linked to inherited forms of parkinsonism have been identified, including 10 causing early-onset (EO) autosomal recessive (AR) forms (PRKN, PINK1, DJ-1, ATP13A2, PLA2G6, FBXO7, DNAJC6, SYNJ1, VPS13C, and PTRHD1) [reviewed in Lunati et al. (2)]. The gene discussed is PRKN; the disease is Parkinson disease.