Autosomal dominant parkinsonism with benign course and typical Lewy-body pathology.

The few previously reported patients with familial parkinsonism and Lewy-body pathology in the substantia nigra displayed a variety of clinical and pathologic syndromes. We now describe a family with very slowly progressive Parkinson's disease (PD) that has, in most cases, responded poorly to levodopa and includes subjective visual difficult. Four personally confirmed cases--with onset at ages 35, 25, 16, and 16-have occurred in three generations, and four suspicious cases have occurred in three other generations. There has been a trend toward progressively younger age of onset. One autopsied case showed a distribution of cell loss and Lewy bodies typical of PD. The hereditary pattern is most compatible with autosomal dominance. This kindred's illness shows that a presumably single Mendelian dominant gene can cause the clinical and pathologic features of PD, and further extends the clinical spectrum of pathologically typical Lewy-body PD.