Paroxysmal kinesigenic choreoathetosis (PKC), firstly reported in 1967, is characterized by recurrent and brief attacks of involuntary movement and causative gene remains unidentified. Using targeted genomic sequencing and conventional Sanger sequencing, the authors identified a spectrum of mutations in proline-rich transmembrane protein 2 (PRRT2). PRRT2 mutations cause only a subset of PKC, which suggests that PKC is genetically heterogeneous. This finding has the potential to improve the understanding of molecular basis, clinical diagnosis and treatment for PKC. (By Professor Ying Liu, http://jmg.bmj.com/content/early/2011/11/30/jmedgenet-2011-100635.abstract?papetoc )