Autosomal dominant torsion dystonia with onset in infancy.

We report a man and his daughter who had onset of dystonia during the first year of life, primarily involving their legs and consisting of both sustained postures and rhythmical 2-3 Hz twisting movements. They also had eccentric and irregularly shaped pupils, but no other neurological abnormalities. This disorder differs from all familial dystonia syndromes described in the literature, including classic idiopathic torsion dystonia, which has a later age of onset. This disorder probably represents a new autosomal dominant dystonia syndrome.