PANK2 and pantothenate kinase-associated neurodegeneration: Among the NBIA subtypes, the most common form of the pathology is caused by mutations in the pantothenate kinase 2 (PANK2) gene, which is responsible for the so-called Pantothenate Kinase-Associated Neurodegeneration (PKAN), a subtype of the disease with an estimated prevalence of three in one million [36,82].