We report two brothers with hereditary motor and sensory neuropathies and pyramidal signs. Electrophysiological evaluation revealed polyneuropathy and involvement of the central motor, somatosensory, and auditory pathways. Brain magnetic resonance imaging studies showed diffuse white matter lesions, and sural nerve biopsy identified a reduction in the large myelinated nerve fibers. The patients' mother and sister exhibited similar, but milder neurologic findings suggesting that the genetic defect may be X-linked; however, a point mutation in the connexin 32 gene was negative.