title: Analysis of dystrophin expression after activation of myogenesis in amniocytes, chorionic-villus cells, and fibroblasts. A new method for diagnosing Duchenne's muscular dystrophy.
abstract: BACKGROUND
  DNA analysis of peripheral-blood leukocytes is routinely used to demonstrate mutations in the dystrophin gene in patients with Duchenne's or Becker's muscular dystrophy. In approximately 35 percent of patients, DNA studies are not informative; in these patients immunochemical analysis of a muscle-biopsy specimen can determine whether dystrophin, the protein product of the gene for Duchenne's dystrophy, is present at reduced levels or absent. DNA analysis can be performed in amniocytes or chorionic-villus cells to identify mutations of the dystrophic gene prenatally, but immunochemical testing for dystrophin cannot be performed because the protein is not expressed in these cells.
  
  
  METHODS
  To circumvent this limitation in prenatal diagnosis, we induced myogenesis in 21 cultures of skin fibroblasts, 49 amniocyte cultures, and 6 chorionic-villus cell cultures by infecting the cells with a retrovirus vector containing MyoD, a gene regulating myogenesis. Transfection of MyoD into cells that do not normally develop into muscle cells results in the production of a protein that switches on myogenesis. We performed immunocytochemical analysis for dystrophin in the MyoD-converted muscle cells.
  
  
  RESULTS
  We found that 60 of 61 myotube cultures from subjects with no family history of Duchenne's dystrophy expressed dystrophin. Both myotube cultures from the two patients with Becker's dystrophy also expressed dystrophin, but all cultures from nine patients and two fetuses with Duchenne's dystrophy were dystrophin-deficient.
  
  
  CONCLUSIONS
  Immunocytochemical analysis of dystrophin in genetically altered non-muscle cells is feasible and may be applicable to the prenatal and postnatal diagnosis of Duchenne's muscular dystrophy when conventional DNA analysis is not informative.
authors.affiliation: Department of Pathology, Columbia University College of Physicians and Surgeons, New York 10032.
authors.forename: S
authors.initials: S
authors.lastname: Sancho
authors.forename: T
authors.initials: T
authors.lastname: Mongini
authors.forename: K
authors.initials: K
authors.lastname: Tanji
authors.forename: S J
authors.initials: SJ
authors.lastname: Tapscott
authors.forename: W F
authors.initials: WF
authors.lastname: Walker
authors.forename: H
authors.initials: H
authors.lastname: Weintraub
authors.forename: A D
authors.initials: AD
authors.lastname: Miller
authors.forename: A F
authors.initials: AF
authors.lastname: Miranda
mesh_terms: D000653:Amniotic Fluid / Q000166:cytology; D002454:Cell Differentiation; D002478:Cells, Cultured; D002824:Chorionic Villi / Q000648:ultrastructure; D016189:Dystrophin / Q000032:analysis* / Q000235:genetics; D005347:Fibroblasts / Q000166:cytology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009132:Muscles / Q000378:metabolism* / Q000648:ultrastructure; D009136:Muscular Dystrophies / Q000175:diagnosis* / Q000235:genetics; D011296:Prenatal Diagnosis
chemical_list: D016189:Dystrophin