Lessons from a remarkable family with dopa-responsive dystonia.

A family is described in which dopa-responsive dystonia affected six members and segregated in an autosomal dominant fashion. Patients either presented in childhood with dystonia of the legs, going to develop parkinsonism and pseudo-pyramidal deficits, or in adult life with parkinsonian tremor and rigidity, with pseudo-pyramidal signs. Remarkably, in the three cases with childhood onset the symptoms and signs of the condition were abolished 36 to 52 years later by small doses of levodopa. No long term side effects of levodopa have appeared after 15 years of treatment.