[DYT1 positive generalised dystonia: a case study of two siblings].

The early-onset generalised dystonia is a dyskinetic movement disorder with a wide variety in phenotype and poor response to pharmacological treatment. A mutation on the DYT1 gene is responsible for the disease in more than 50% of cases with typical early-onset dystonia beginning in a limb. We describe the medical history of two brothers with first signs of focal dystonia at age 12 starting with right side lower limb dystonia of the older brother and writers cramp of the younger one. In both over a period of 6 and 10 years dystonia generalised. The negative results of MRI, electrophysiological testing and muscle biopsy corroborate the diagnosis of primary dystonia. The DNA from the older patient was tested for the 3 bp deletion in exon 5 of the DYT1 gene by restriction enzyme. The positive result confirmed the diagnosis of early-onset primary dystonia. A short synopsis of routine molecular genetic tests indications and treatment options is outlined.