Western Nebraska family (family D) with autosomal dominant parkinsonism.

The etiology of Parkinson's disease (PD) remains uncertain. Environmental influences may have an important role, but genetic factors have been firmly implicated in several recently reported kindreds. We studied a family (family D) whose ancestors probably immigrated to the United States from England. The pedigree contains 188 individuals spanning six generations with 18 affected members. Autosomal dominant inheritance is present. Typical levodopa-responsive PD with bradykinesia, rigidity, resting tremor, and impaired postural reflexes develops. Eye movement abnormalities, pyramidal and cerebellar signs, sensory disturbances, and orthostatic blood pressure changes do not occur. Disease progression is slow. PET with [18F]-6-fluoro-L-dopa (FD) performed on an affected individual revealed decreased uptake of FD in a pattern consistent with PD. Autopsy performed on another affected individual demonstrated neuronal and pigmentary loss, gliosis, and Lewy bodies in the substantia nigra pars compacta. This large kindred appears to represent a neurodegenerative disorder closely resembling, if not identical to, idiopathic PD.