PRKN and Parkinson disease: Parkin mutations have been found in PD patients of different ethnicity and have been considered as the major mutant factor for familial autosomal recessive juvenile parkinsonism (ARJP), with 50% of ARJP beyond the age of 25 and 3–7% of PD patients at ages of 30–45 years, carrying a mutation in this gene [2,51].