Spinal muscular atrophy due to a "de novo" 1.3 Mb deletion: implication for genetic counseling

Neuromuscul Disord. 2013 May;23(5):388-90. doi: 10.1016/j.nmd.2013.01.009. Epub 2013 Mar 1.

Abstract

We report a 3-year-old female with type I spinal muscular atrophy (SMA) born to a young and non-consanguineous couple. The child presented at two months of life with intense muscle weakness affecting predominantly proximal portions of the limbs, especially the legs, muscle hypotonia, fasciculation of the tongue, and severe respiratory muscle involvement. She remained in an intensive care unit with an assisted ventilation system from the fourth month of life. She died at 3 years of age from pulmonary infection. Molecular analysis confirmed the diagnosis of SMA but revealed that only the father was an asymptomatic carrier. Because SMN1 is mapped in a complex region containing repetitive elements due to an inverted duplication of approximately 500 kb, we carry out an SNP array and detected a 1.3 Mb deletion including the SMN1 and SMN2 genes that explain the disease.

Publication types

  • Case Reports

MeSH terms

  • Child, Preschool
  • Fatal Outcome
  • Female
  • Genetic Counseling / methods
  • Humans
  • Muscular Atrophy, Spinal / diagnosis
  • Muscular Atrophy, Spinal / genetics*
  • Polymorphism, Single Nucleotide / genetics
  • Polymorphism, Single Nucleotide / physiology
  • SMN Complex Proteins / genetics*
  • Sequence Deletion / genetics*
  • Survival of Motor Neuron 1 Protein / genetics*
  • Survival of Motor Neuron 2 Protein / genetics*

Substances

  • SMN Complex Proteins
  • Survival of Motor Neuron 1 Protein
  • Survival of Motor Neuron 2 Protein