Clinical and pathological heterogeneity in late-onset partial merosin deficiency

Muscle Nerve. 2011 Oct;44(4):590-3. doi: 10.1002/mus.22196.


Mutations in the LAMA2 gene result in a complete loss of merosin and underlie a severe congenital type of muscular dystrophy (MDC1A).We investigated the clinical, genetic, and histological basis of late-onset muscular dystrophy in one family. The proband and her affected brother exhibited late-onset predominantly proximal muscle weakness. In addition, the proband experienced seizures. Magnetic resonance imaging of her brain demonstrated white-matter abnormalities. Sequencing of LAMA2 identified two new heterozygous point mutations in the two affected members. Muscle histology demonstrated dystrophic features, rimmed vacuoles, and partial loss of laminin α immunoreactivity. Partial merosin deficiency can present with a mild, late-onset limb-girdle-type pattern of weakness, with or without epilepsy, and pathologically may exhibit features observed in inclusion-body myopathy.

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism
  • Electroencephalography / methods
  • Family Health
  • Female
  • Humans
  • Laminin / deficiency*
  • Laminin / genetics
  • Laminin / metabolism
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Muscle, Skeletal / metabolism
  • Muscle, Skeletal / pathology
  • Muscle, Skeletal / ultrastructure
  • Muscular Dystrophies / genetics
  • Muscular Dystrophies / metabolism*
  • Muscular Dystrophies / pathology*
  • Sequestosome-1 Protein
  • Utrophin / metabolism


  • Adaptor Proteins, Signal Transducing
  • Laminin
  • SQSTM1 protein, human
  • Sequestosome-1 Protein
  • Utrophin
  • laminin alpha 2