1. Schematic depiction of the effect of different types of Duchenne muscular dystrophy (DMD)-causing mutations on the dystrophin transcript.
Schematic depiction of the effect of different types of Duchenne muscular dystrophy (DMD)-causing mutations on the dystrophin transcript. (A) Deletions of one or more exons can cause a shift of the open reading frame (in this example, a deletion of exon 45). (B) A duplication of one or more exons can cause a shift of the open reading frame (in this example, a duplication of exon 2). (C) There are several types of small mutations than can cause DMD. Nonsense mutations (top panel) introduce a stop codon prematurely (in this example, the nonsense mutation is located in exon 35). Small insertions or deletions (middle panel) can disrupt the open reading frame (in this example, a 1 bp insertion in exon 35). Finally, mutations affecting the splice sites (bottom panel) generally lead to the exclusion of the affected exon from the mRNA (in this example, exon 43). As such, a single-exon deletion that disrupts the open reading frame is generated on the mRNA level.
Annemieke Aartsma-Rus et al. J Med Genet doi: /jmedgenet
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