Linkage of a Gene Causing Familial Amyotrophic Lateral Sclerosis to Chromosome 21 and Evidence of Genetic-Locus Heterogeneity

A MYOTROPHIC lateral sclerosis, often referred to as Lou Gehrig's disease, motor neuron disease, or Charcot's syndrome, is a devastating paralytic disorder with onset in adulthood, caused by degeneration of large motor neurons of the brain and spinal cord. 1 It causes generalized and progressive wasting and weakness of skeletal muscles 2 and usually results in death within five years. 2 Currently there is no treatment to prevent this disease or to alter its unremitting course. Its annual incidence is similar to that of multiple sclerosis and more than five times that of Huntington's disease. 3 Since the average duration of life after the . . .