The nosology of the spinal muscular atrophies.

Case Report. We have studied a patient with scapuloperoneal muscular atrophy in whom muscle weakness was first noticed at age 35 after 10 days bed rest with a swollen and painful leg following a smallpox vaccination. This man has an affected cousin in whom muscle weakness developed insidiously, the onset of which was not clearly associated with any particular exogenous factor. An apparent increase in the incidence of sporadic cases of infantile spinal muscular atrophy (Werdnig- 481 copyright.