Genetic disorders of motor neurons.

Disorders of the motor neuron are etiologically and clinically heterogeneous and cause serious disability and death. Whereas mendelian inheritance can be demonstrated in a subset of these disorders, the genetic contribution to the sporadic forms of motor neuron degeneration are not well understood. In families with spinal muscular atrophy, Kennedy disease and amyotrophic lateral sclerosis, genetic linkage analysis and positional cloning have proven to be extremely productive. The genetics of these neurodegenerative disorders are reviewed.