The PANK2 gene at 20p13 codes for the 570 amino acid pro-peptide to pantothenate kinase 2, mitochondrial. There are 4 isoforms. Pantothenic acid kinase 2 catalyses the first step in coenzyme A biosynthesis:
ATP + (R)-pantothenate => ADP + (R)-4-phosphopantothenate.
Mutations of PANK2 are a cause of pantothenate kinase associated neurodegeneration(PKAN) with brain iron accumulation which manifests as neuroacanthocytosis and on cerebral MRI the "eye of the tiger" sign. Presentation is: