Base substitutions in the human dystrophin gene: detection by using the single-strand conformation polymorphism (SSCP) technique.

We have established the experimental conditions to screen twenty regions of the dystrophin gene using the method of single-strand conformational polymorphism (SSCP) analysis. The aim of this study was to identify point mutations in patients with Duchenne or Becker muscular dystrophy (DMD or BMD) who have no gross DNA rearrangements detectable by Southern blot analysis or multiplex exon amplification. The investigation of thirteen patients using this procedure resulted in the detection of seven sequence polymorphisms (four identified in this study) that will be useful allelic markers in familial DNA analysis. Three rare sequence variants could be found (two of them being novel variants) but we were unable to demonstrate mutations that could be clearly sufficient to be responsible for the phenotype. This analysis confirmed the efficiency of the SSCP technique for the detection of nucleotide substitutions. Application of this approach to mutation or polymorphism detection to other exons of the gene will improve carrier and prenatal diagnosis.