Clinical and molecular genetic evaluation of patients with primary dystonia.
Primary dystonia is a movement disorder characterized by involuntary and sustained muscle contractions causing twisting or abnormal postures and mutations in several genes have been identified. Our goal was to investigate, whether the clinical presentation would differ between patients with a positive family history, and patients without. Furthermore, we have performed mutation analysis in the subgroup of patients with a positive family history. A total of 175 patients with primary dystonia were evaluated. Data on gender, presence and frequency of pain and tremor, age of onset, and the distribution of affected body parts were compared between patients with positive and negative family history. All exons of the torsion dystonia 1, GTP cyclohydrolase 1 and epsilon-sarcoglycan genes were examined in 40 patients by SSCP analysis of PCR products followed by sequencing of variant conformers. Dystonia patients with a positive family history of dystonia had an earlier age of onset and those with a positive family history of tremor more often associated tremor than those with a negative family history. Four new polymorphisms in the epsilon-sarcoglycan gene were found and others confirmed, but no known or new mutations could be detected. Our study supports the notion that primary dystonia is a genetically heterogeneous disease.