Infantile spinal muscular atrophy with respiratory distress type I (SMARD 1): an atypical phenotype and review of the literature

Eur J Paediatr Neurol. 2012 Jan;16(1):90-4. doi: 10.1016/j.ejpn.2011.10.005. Epub 2011 Nov 18.

Abstract

Spinal muscular atrophy with respiratory distress (SMARD 1) is a very rare autosomal recessive motor neuron disorder that affects infants and is characterized by diaphragmatic palsy, symmetrical distal muscular weakness, muscle atrophy, peripheral sensory neuropathy and autonomic nerve dysfunction. SMARD 1 is inherited as an autosomal recessive trait and the mutations have been identified in the gene encoding immunoglobulin μ-binding protein 2 (IGHMBP2), located on chromosome 11q13. It is considered a fatal form of infantile motoneuron disease and most of the patients dies within the first 13 months of life. We present a female child with genetically confirmed SMARD 1 displaying a mild phenotype and no severe signs of respiratory involvement, typically found in this form, up to 38 months despite a diaphragmatic palsy diagnosed at 6 months of age. Therefore, our clinical observation suggests that respiratory failure is not secondary, in any case, to the diaphragmatic palsy but other pathogenetic mechanisms might be involved.

Publication types

  • Case Reports
  • Review

MeSH terms

  • Child Development / physiology
  • DNA-Binding Proteins / genetics*
  • Female
  • Humans
  • Infant
  • Phenotype*
  • Radiography
  • Respiratory Insufficiency / diagnostic imaging
  • Respiratory Insufficiency / genetics*
  • Respiratory Paralysis / diagnostic imaging
  • Respiratory Paralysis / genetics*
  • Spinal Muscular Atrophies of Childhood / diagnostic imaging
  • Spinal Muscular Atrophies of Childhood / genetics*
  • Transcription Factors / genetics*

Substances

  • DNA-Binding Proteins
  • IGHMBP2 protein, human
  • Transcription Factors