Presence of the Eye-of-the-tiger Sign on Magnetic Resonance Imaging in a Subject with Atypical Hallervorden-Spatz Syndrome Lacking Pantothenate Kinase 2 Mutation

Hallervorden-Spatz syndrome (HSS) is generally considered to be a rare neurodegenerative disorder associated with autosomal recessive pantothenate kinase-associated neurodegeneration or neurodegeneration with brain iron accumulation. The most well-known hallmark of the syndrome is the eye-of-the-tiger sign on the brain magnetic resonance imaging (MRI) scan. Previous studies have highlighted a one-to-one correlation between the MRI findings of the eye-of-the-tiger sign and the presence of a pantothenate kinase 2 (PANK2) mutation, postulating that the MRI appearance is a good diagnostic tool for identifying PANK2 mutation-positive cases. We report an atypical HSS patient without a PANK2 mutation, who had an eye-of-the-tiger sign on MRI, therefore strengthening the notion of genetic and radiological heterogeneity in HSS.