PRKN and metabolic process: Furthermore, recessive early-onset Parkinson’s disease type 2 (Parkin-PRKN-deficiency) and type 6 (PINK1 deficiency) are classified in group 11 of the ICIMD nosology (“Other disorders of mitochondrial function”), while early-onset Parkinson’s disease type 20 (Synaptojanin 1 deficiency) is included in group 14 (“Disorders of lipid metabolism”).