Although mutations in PARK2 (PRKN; MIM #602544), PARK6 (PINK1; MIM #605909), and PARK7 (DJ1, MIM #606324) are infrequent in the PD population, they are responsible for a majority of early-onset PD and are usually known to cause typical PD with indistinguishable clinical signs (1, 4, 6). This evidence concerns the gene PRKN and Parkinson disease.