A POSSIBLE MISSENSE MUTATION DETECTED IN THE DYSTROPHIN GENE BY DOUBLE-STRAND CONFORMATION ANALYSIS (DSCA)

A new and simple method for detecting point mutations is presented. Th e method, based on Double-Strand Conformation Analysis (DSCA) of PCR a mplification products in polyacrylamide gel electrophoresis, was appli ed to 78 unrelated subjects affected with Duchenne or Becker muscular dystrophy and to 9 subjects suspected to be affected with an atypical dystrophinopathy. An A-->G substitution in the nucleotide 2525, which changes the codon for lysine to a codon for glutamic acid was detected in an 8-year-old boy, with normal neurological examination, but showi ng increased CK level and an abnormal EMG. The muscle biopsy was norma l, without features of necrosis or regeneration. Immunoreactions with anti-dystrophin antibodies showed a normal distribution and intensity of the staining. A review of the dystrophin mutations detected so far is included.