Spinal muscular atrophy
- Type 1 (Werdnig-Hoffman disease) is characterized by symptom onset before 6 months of age. These patients are profoundly hypotonic, have significant respiratory and nutritional difficulties, and never achieve sitting without support. Historically, this type is fatal within 2 years.
- Type 2 is characterized by symptom onset between 6-12 months, weakness, tremors, and respiratory and nutritional problems. These patients are able to achieve sitting but never walk independently.
- Type 3 is the least severe type and is characterized by symptom onset after 1 year of age. Many live into adulthood and achieve walking prior to losing this ability in late childhood or early adulthood. The weakness in type 3 is variable. These patients typically do not have respiratory or nutritional difficulties.
For more information on SMA type 1, see OMIM.
For more information on SMA type 2, see OMIM.
For more information on SMA type 3, see OMIM.
G12.9 – Spinal muscular atrophy, unspecified
5262007 – Spinal muscular atrophy
- Spinal muscular atrophy with respiratory distress (SMARD1)
- X-linked infantile spinal muscular atrophy
- Congenital myopathy
- Toxic / metabolic etiologies of hypotonia
- Congenital myasthenic syndrome
- Congenital myotonic dystrophy
- Arthrogryposis multiplex congenita
- Prader-Willi syndrome
- Lysosomal storage diseases (eg, Pompe disease)
- Muscular dystrophies
- Non-5q forms of SMA
- Lysosomal storage diseases
- Guillain-Barré syndrome (distinguishable by subacute-acute onset and pattern of presenting weakness)
- Congenital myopathies
- Infantile botulism
- Spinal-dural arteriovenous malformation / fistula
- Postpolio syndrome
- West Nile virus
- Facioscapulohumeral muscular dystrophy
- Amyotrophic lateral sclerosis
- Kennedy disease (spinobulbar muscular atrophy)
- Chronic inflammatory demyelinating polyneuropathy
- Multifocal motor neuropathy
- Lead toxicity
- Dapsone toxicity