In a recent study enrolling 11 PKAN patients that were heterogeneous with respect to the specific Pank2 mutation, we found mean percent acanthocyte counts of 30.9 ± 10.0 and 1.7 ± 1.4 for acanthocyte-positive (n = 6) and acanthocyte-negative (n = 5) PKAN blood samples, respectively [5]. This evidence concerns the gene PANK2 and pantothenate kinase-associated neurodegeneration.