Congenital muscular dystrophy with primary laminin alpha2 (merosin) deficiency presenting as inflammatory myopathy

Ann Neurol. 1996 Nov;40(5):782-91. doi: 10.1002/ana.410400515.


Ten laminin alpha2-deficient patients were identified by both immunofluorescence and immunoblotting (30% of congenital muscular dystrophy patients tested). Three of the laminin alpha2-deficient patients were carrying a diagnosis of infantile polymyositis prior to immunostaining studies. The clinical features in the 10 merosin-deficient patients were homogeneous, with severe floppiness at birth, delay in achievement of motor milestones, and magnetic resonance imaging findings of white matter changes with normal intelligence. The 10-kb laminin alpha2-coding sequence was screened for causative mutations by reverse transcriptase-polymerase chain reaction/single-stranded conformational polymorphism analysis in muscle biopsy specimens from 5 patients, followed by automatic sequencing of aberrant conformers. Clear loss-of-function deletion mutations were identified in both alleles of 1 patient. Muscle histopathology in this patient showed a striking inflammatory infiltrate of T cells and B cells. Reexamination of biopsy specimens from other laminin alpha2-deficient patients showed minor signs of inflammation in each. Based on these findings and the histological and clinical picture suggesting failure of muscle regeneration, a pathogenesis model for this major subset of congenital muscular dystrophy is proposed. Our data show that muscle histopathology showing a neonatal inflammatory process should be considered consistent with congenital muscular dystrophy.

Publication types

  • Case Reports
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Base Sequence
  • Biopsy
  • Child
  • Child, Preschool
  • Deoxyribonucleases, Type II Site-Specific
  • Electromyography
  • Female
  • Humans
  • Infant
  • Infant, Newborn
  • Inflammation
  • Laminin / deficiency*
  • Laminin / genetics
  • Middle Aged
  • Motor Activity
  • Muscle, Skeletal / pathology*
  • Muscle, Skeletal / physiopathology
  • Muscular Dystrophies / congenital
  • Muscular Dystrophies / genetics*
  • Muscular Dystrophies / physiopathology*
  • Nuclear Family
  • Pedigree
  • Point Mutation
  • Polymerase Chain Reaction
  • Polymorphism, Restriction Fragment Length
  • Polymorphism, Single-Stranded Conformational*
  • Polymyositis / physiopathology*
  • Sequence Deletion


  • Laminin
  • Deoxyribonucleases, Type II Site-Specific
  • GANTC-specific type II deoxyribonucleases