Fast Five Quiz: Acute Infantile Spinal Muscular Atrophy Type 1, or Werdnig-Hoffmann Disease

Stephen L. Nelson, Jr, MD, PhD


August 12, 2020

Figure 1. Light micrograph of normal muscle fibers showing atrophy of skeletal muscle with denervation

Approximately 80% of patients with SMA have SMA type 1, or Werdnig-Hoffman disease. In these patients, the disorder is severe. Muscle weakness, lack of motor development, and poor muscle tone are the major clinical manifestations of SMA type 1. The median survival of patients with SMA type 1 is just 7 months, with a mortality rate of 95% by age 18 months. New and emerging treatments may help to maximize outcomes in these patients.

Learn more about SMA type 1.


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