Interplay between DMD point mutations and splicing signals in Dystrophinopathy phenotypes

PLoS One. 2013;8(3):e59916. doi: 10.1371/journal.pone.0059916. Epub 2013 Mar 25.

Abstract

DMD nonsense and frameshift mutations lead to severe Duchenne muscular dystrophy while in-frame mutations lead to milder Becker muscular dystrophy. Exceptions are found in 10% of cases and the production of alternatively spliced transcripts is considered a key modifier of disease severity. Several exonic mutations have been shown to induce exon-skipping, while splice site mutations result in exon-skipping or activation of cryptic splice sites. However, factors determining the splicing pathway are still unclear. Point mutations provide valuable information regarding the regulation of pre-mRNA splicing and elements defining exon identity in the DMD gene. Here we provide a comprehensive analysis of 98 point mutations related to clinical phenotype and their effect on muscle mRNA and dystrophin expression. Aberrant splicing was found in 27 mutations due to alteration of splice sites or splicing regulatory elements. Bioinformatics analysis was performed to test the ability of the available algorithms to predict consequences on mRNA and to investigate the major factors that determine the splicing pathway in mutations affecting splicing signals. Our findings suggest that the splicing pathway is highly dependent on the interplay between splice site strength and density of regulatory elements.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Dystrophin / genetics*
  • Dystrophin / metabolism
  • Exons
  • Female
  • Frameshift Mutation
  • Genotype
  • Humans
  • Male
  • Muscular Dystrophy, Duchenne / genetics*
  • Muscular Dystrophy, Duchenne / metabolism*
  • Muscular Dystrophy, Duchenne / pathology
  • Mutation, Missense
  • Phenotype*
  • Point Mutation*
  • RNA Splice Sites
  • RNA Splicing*

Substances

  • Dystrophin
  • RNA Splice Sites

Grants and funding

This study was supported by grants from Fondo de Investigación Sanitaria (PI08/0347) and CIBER de Enfermedades Raras (U-705) initiatives of Instituto de Salud Carlos III (www.isciii.es). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.