Hereditary motor neuron disease

Nine cases of motor neuron disease (amyotrophic lateral sclerosis) in one family over 3 generations are presented. In 2 instances the disease was transmitted from parent to child. Several of the patients were first cousins. There was no skipping of a generation. The positive family history had been overlooked by several neurologists, although they had enquired for it. Familial motor neuron disease accounts for at least 10% of cases of this disorder.