Autosomal dominant motor system degeneration in a black family.

Autosomal dominant motor system degeneration has been described primarily in Portuguese families from the Azorean Islands. The symptoms include various combinations of ataxia, pyramidal and extrapyramidal signs, appendicular dystonias, tics, ophthalmoplegias, and peripheral neuropathies with amyotrophy. One non-Portuguese, non-Azorean black family has been described previously; this report describes a second such family affected by autosomal dominant motor system degeneration.