MICROLESIONS AND POLYMORPHISMS IN THE DUCHENNE BECKER MUSCULAR-DYSTROPHY GENE/

One third of mutations responsible for Duchenne or Becker muscular dys trophy (DMD/BMD) represent point mutations or other small sequence alt erations not readily detectable by Southern blot analysis or multiplex amplification. Here, we report results of a comprehensive point mutat ion search that yielded seven new sequence variations and one novel po lymorphism. We also summarize known mutations, polymorphisms and other small nucleotide variations in the DMD gene. To date, 12 non sense mu tations, two missense mutations, six microdeletions and one microinser tion have been reported in the coding sequence and a further six mutat ions in splice sites all of which were made responsible for the diseas e. Twelve polymorphisms with frequencies suitable for diagnostic purpo ses have been detected. A further 28 differences from the published se quence of the coding sequence or the promotor region are described.