A 61 year old woman and her 58 year old brother presented with the clinical picture of late onset progressive bulbar and spinal muscular atrophy with family history of involvement in successive generations. The sister also had optic neuropathy and the brother developed diabetes mellitus and sex hormone abnormalities. Neurophysiological and histopathological studies showed a pattern of motor and sensory neuronopathy. There was no abnormal expansion of CAG repeats in the androgen receptor gene. This family seems to have a previously unrecognised entity with the bulbospinal neuronopathy phenotype.