Phenotypic variability of the DYT1 mutation in German dystonia patients

Primary dystonia is a clinically and genetically heterogeneous movement dis order characterized by sustained involuntary muscle contractions causing re petitive movements and/or abnormal pastures. Recently, the gene locus (DYT1 ) and mutation responsible for a substantial number of cases suffering from early-onset primary dystonia was described. Here we report 2 German famili es and 1 sporadic patient with early-onset dystonia due to the DYT1 mutatio n in order to illustrate the variability of clinical manifestation within t his molecularly defined entity. We demonstrate that writer's cramp or focal cervical dystonia is a clinical presentation of DYT1 as well as generalize d dystonia.