[A Japanese family with paroxysmal dystonic choreoathetosis]

We present the first report of Japanese family with paroxysmal dystonic choreoathetosis (PDC). At least seventeen individuals of this family in six generations were affected by PDC by autosomal dominant inheritance. The affected individuals had attacks of choreoathetosis/dystonia-like involuntary movements without loss of consciousness. These attacks were precipitated by stress, caffeine, menstruation or ovulation, but not by sudden voluntary movements, which are common precipitating factors in paroxysmal kinesigenic choreoathetosis (PKC). MRI studies of the brain revealed no abnormalities. Some of the family members received clonazepam, or garlic with significant therapeutic effects, while one female case improved after hysterectomy. The pathogenesis of PDC remains unknown, but it could be attributed to a form of channelopathy. Recently, two linkage studies were reported and the PDC locus was identified on chromosome 2q, which may lead to clarify the PDC gene. The family described here may be important for the future biochemical and genetic analyses. We also suspect that PDC may relate to endocrinological abnormalities besides channelopathy.