title: Immunohistochemical evaluation of merosin deficiency in congenital muscular dystrophies.
abstract: OBJECTIVE
  To determine the prevalence of merosin deficiency in cases of unclassified congenital muscular dystrophy and to determine the temporal stability of merosin epitopes in fixed and stored archival material.
  
  
  METHODS
  Using an antibody to human merosin we retrospectively studied 12 cases of undiagnosed muscular dystrophy from our files to determine the prevalence of merosin deficiency. Where fresh muscle was not available, unstained stored cryostat sections or destained archival stored sections were incubated with the merosin antibody.
  
  
  RESULTS
  Two of the 12 cases of undiagnosed muscular dystrophy were merosin-deficient. No difference in intensity of merosin staining was found between freshly cut cryostat sections and unstained stored cryostat sections. There was no difference in the intensity of merosin staining in sections archived for up to 10 years.
  
  
  CONCLUSIONS
  We conclude that 16% of unclassified muscular dystrophies in our study are due to merosin deficiency and that merosin antigenicity remains intact in archival stored muscle tissue, facilitating retrospective evaluation of patients in whom frozen muscle is not available. To our knowledge, this latter observation has not been reported previously.
authors.affiliation: Department of Neuropathology, Beaumont Hospital, Dublin, Ireland.
authors.forename: F M
authors.initials: FM
authors.lastname: Brett
authors.forename: P
authors.initials: P
authors.lastname: Loring
authors.forename: A
authors.initials: A
authors.lastname: Caesar
authors.forename: M
authors.initials: M
authors.lastname: Burke
authors.forename: R P
authors.initials: RP
authors.lastname: Brennan
authors.forename: M
authors.initials: M
authors.lastname: King
authors.forename: M A
authors.initials: MA
authors.lastname: Farrell
mesh_terms: D001706:Biopsy / Q000379:methods; D002648:Child; D016616:Cryoultramicrotomy; D005260:Female; D006801:Humans; D007106:Immune Sera / Q000032:analysis / Q000276:immunology; D007150:Immunohistochemistry; D007797:Laminin / Q000032:analysis / Q000172:deficiency* / Q000276:immunology; D008659:Metabolic Diseases / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology; D018482:Muscle, Skeletal / Q000737:chemistry / Q000378:metabolism / Q000473:pathology; D009136:Muscular Dystrophies / Q000151:congenital* / Q000378:metabolism* / Q000473:pathology; D015995:Prevalence; D012189:Retrospective Studies
chemical_list: D007106:Immune Sera; D007797:Laminin