The prevalence of PARKIN mutations in the young‐onset (<45 years) sporadic PD population has been estimated to be about 15% (Periquet et al., 2003), and this increases to almost 50% for familial young‐onset cases with a recessive pattern of inheritance (Bonifati, 2012; Lücking et al., 2000). The gene discussed is PRKN; the disease is Parkinson disease.