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Collaborative Hypertext of Radiology

Musculoskeletal system



spinal muscular atrophy

2nd most common autosomal recessive disease in Caucasians

  • pathology
    • degeneration of the spinal anterior horn cells
    • atrophy and wasting of skeletal muscles

  • types
    • SMA I = Werdnig-Hoffman disease: rapidly progressive
    • SMA II = intermediate form
    • SMA III = Kugelberg-Welander disease: slowly progressive
    • uncommon adult forms

  • usual presentations
    • floppy baby
    • arthrogryposis
    • muscle weakness in infancy

  • diagnosis
    • weakness and wasting with areflexia
    • electrophysiology shows anterior horm cell disease

  • genetics
    • linked to chromosome 5q.
    • neuronal apoptosis inhibitory protein (NAIP) gene
    • survival motor neuron (SMN) gene

James Lowe, DM BM BS MRCPath  -  13 November 1997
Last updated:  1 October 2013


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block vertebra


Copyright © 2013, Charles E. Kahn, Jr.