title: A deletion hot spot in the Duchenne muscular dystrophy gene.
abstract: We have made a detailed study of a deletion hot spot in the distal half of the Duchenne muscular dystrophy (DMD) gene, using intragenic probe P20 (DXS269), isolated by a hybrid cell-mediated cloning procedure. P20 detects 16% deletions in patients suffering from either DMD or Becker muscular dystrophy (BMD), in sharp contrast to the adjacent intragenic markers JBir (7%) and J66 (less than 1%), mapping respectively 200-320 kb proximal and 380-500 kb distal to P20. Of the P20 deletions, 30% start within a region of 25-40 kb, the majority extending distally. P20 was confirmed to map internal to a distal intron of the DMD gene. This region was recently shown by both cDNA analysis (M. Koenig et al., 1987; Cell 50: 509-517), and field inversion electrophoresis studies (J.T. Den Dunnen et al., 1987, Nature (London) 329: 640-642) to be specifically prone to deletions. In addition, P20 detects MspI and EcoRV RFLPs, informative in 48% of the carrier females. Together, these properties make P20 useful for carrier detection, prenatal diagnosis, and the study of deletion induction in both DMD and BMD.
mesh_terms: D002460:Cell Line; D002872:Chromosome Deletion; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D003360:Cosmids; D004587:Electrophoresis, Agar Gel; D006801:Humans; D006822:Hybrid Cells; D007120:Immunochemistry; D008297:Male; D009136:Muscular Dystrophies / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length