Abstract
76 cases of acute Werdnig-Hoffmann disease (acute infantile spinal muscular atrophy) have been reviewed. The cases comprise an unselected consecutive series in which rigid diagnostic criteria have been applied. The natural history of the disease has been investigated. In at least one-third of cases the disease is manifest before or at delivery. All cases have shown delayed milestones by 5 months of age: 95% are dead by 18 months. Cumulative frequency curves for age at onset and age at death figures are presented for use both as prognostic guidelines and as aids in the management of sibs of index cases. Diagnosis, management, and genetic implications are discussed.