ANALYSIS OF DELETION BREAKPOINTS IN DYSTROPHIN TRANSCRIPTS

Duchenne and Becker muscular dystrophies are allelic X-linked disorders resulting from defects in the gene coding for the dystrophin muscle protein. The dystrophin gene is more than 2300kb in size and consists of 79 exons. This large size and complexity presents a challenge to direct identification of point mutations and small deletions that cannot be identified by multiplex deletion testing or Southern blotting. One approach to this problem is to analyse the expression of ectopic dystrophin mRNA transcripts. Although the dystrophin gene transcript is distributed only over approximately 0.1% of the genome, analysis of such ectopic lymphocyte dystrophin transcripts can shed light on the pathogenic events at the transcriptional level.