Age at disease onset predicts likelihood and rapidity of growth failure among infants and young children with spinal muscular atrophy types 1 and 2

J Child Neurol. 2012 Jul;27(7):845-51. doi: 10.1177/0883073811415680. Epub 2012 Mar 30.


Growth failure is nearly universal in spinal muscular atrophy type 1 and common in type 2, although acuity is often underappreciated at initial diagnosis. We reviewed 44 consecutive spinal muscular atrophy patients (28 type 1, 16 type 2) under 3 years at initial presentation. Growth failure was conventionally defined: weight below the fifth percentile or dropping 2 major percentiles over 6 months. Growth failure differed among subjects stratified by age at disease onset using the Kaplan-Meier method (P = 0.011). Median time to growth failure among subjects with onset between 0 to 3 months of age was 5 months; Only 1 of 22 avoided failure by 22 months of age. Median time to failure with disease onset between 4 to 6 months was 15 months. Most late onset (> 6 months) subjects avoided growth failure. Early clinical symptoms predict feeding dysfunction and growth failure. Immediate, proactive nutritional intervention is indicated for patients with early symptom onset.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age of Onset
  • Anthropometry
  • Child, Preschool
  • Cohort Studies
  • Developmental Disabilities / diagnosis*
  • Developmental Disabilities / etiology*
  • Developmental Disabilities / mortality
  • Female
  • Humans
  • Infant
  • Infant, Newborn
  • Kaplan-Meier Estimate
  • Likelihood Functions
  • Male
  • Predictive Value of Tests
  • Retrospective Studies
  • Spinal Muscular Atrophies of Childhood / complications*