Pantothenate kinase 2 mutation with classic pantothenate-kinase-associated neurodegeneration without 'eye-of-the-tiger' sign on MRI in a pair of siblings.

It has been postulated that all patients with pantothenate kinase 2 (PANK2) mutations causing pantothenate-kinase-associated neurodegeneration (PKAN) are associated with the 'eye-of-the-tiger' sign on MRI. We report a pair of siblings who presented with dystonia and who have been found to be homozygous for 104C>A, S35X mutation, confirming the diagnosis of PKAN. They do not have the typical iron deposition in the globi pallida or substantia nigra on MR imaging.