Patients and clinical evaluation:
We report the case of a 17-year-old Moroccan girl suffering from myoclonic dystonia, whose first symptoms began since her childhood: essential resting myoclonuses and actions accentuated by stress and emotion with a slight psychomotor retardation. The patient was operated at the age of two years for ventricular communication with good progress. The disease is segregated in this Moroccan family in autosomal dominant form on the paternal side (6 cases) and over three generations (Figure 1), with incomplete penetrance. The parents are phenotypically normal. Cytogenetic examination showed a normal karyotype. The genetic study was approved by the ethic committee of Cheikh Khalifa Hospital according to the declaration of Helsinki protocol and all subjects gave a written informed consent before testing.