Mutations in PRRT2 result in paroxysmal dyskinesias with marked variability in clinical expression

Paroxysmal dyskinesias (PD) are a group of neurological disorders with episodes of involuntary movements that can be classified into three main categories: paroxysmal kinesigenic dyskinesia (PKD) , paroxysmal exercise induced dyskinesia (PED) and paroxysmal nonkinesigenic dyskinesia(PNKD). Interestingly, PDs may be variably associated with epilepsy. Description of familial infantile convulsions with paroxysmal choreoathetosis (ICCA) and its linkage to the same region with PKD gave the first genetic evidence for common mechanisms shared by PD and certain forms of epilepsy. Our findings show that PKD, ICCA and other PD-related phenotypes could be caused by mutation in the same PRRT2 gene, suggesting that these phenotypes are part of the same phenotypic spectrum. (By Dr. Qing Liu, http://jmg.bmj.com/content/early/2011/12/29/jmedgenet-2011-100653.abstract?papetoc )