title: New developments in exon skipping and splice modulation therapies for neuromuscular diseases.
abstract: BACKGROUND
  Antisense oligonucleotide (AON) therapy is a form of treatment for genetic or infectious diseases using small, synthetic DNA-like molecules called AONs. Recent advances in the development of AONs that show improved stability and increased sequence specificity have led to clinical trials for several neuromuscular diseases. Impressive preclinical and clinical data are published regarding the usage of AONs in exon-skipping and splice modulation strategies to increase dystrophin production in Duchenne muscular dystrophy (DMD) and survival of motor neuron (SMN) production in spinal muscular atrophy (SMA).
  
  
  METHODS
  In this review, we focus on the current progress and challenges of exon-skipping and splice modulation therapies. In addition, we discuss the recent failure of the Phase III clinical trials of exon 51 skipping (drisapersen) for DMD.
  
  
  CONCLUSIONS
  The main approach of AON therapy in DMD and SMA is to rescue ('knock up' or increase) target proteins through exon skipping or exon inclusion; conversely, most conventional antisense drugs are designed to knock down (inhibit) the target. Encouraging preclinical data using this 'knock up' approach are also reported to rescue dysferlinopathies, including limb-girdle muscular dystrophy type 2B, Miyoshi myopathy, distal myopathy with anterior tibial onset and Fukuyama congenital muscular dystrophy.
authors.affiliation: University of Alberta, Faculty of Medicine and Dentistry, Department of Medical Genetics , Edmonton, Alberta , Canada.
authors.forename: Aleksander
authors.initials: A
authors.lastname: Touznik
authors.forename: Joshua J A
authors.initials: JJ
authors.lastname: Lee
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Yokota
mesh_terms: D000818:Animals; D005091:Exons; D005786:Gene Expression Regulation; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D009134:Muscular Atrophy, Spinal / Q000235:genetics / Q000503:physiopathology / Q000628:therapy*; D049288:Muscular Dystrophies, Limb-Girdle / Q000235:genetics / Q000503:physiopathology / Q000628:therapy*; D020388:Muscular Dystrophy, Duchenne / Q000235:genetics / Q000503:physiopathology / Q000628:therapy*; D016376:Oligonucleotides, Antisense / Q000627:therapeutic use*; D012326:RNA Splicing; D016896:Treatment Outcome; D058494:Walker-Warburg Syndrome / Q000235:genetics / Q000503:physiopathology / Q000628:therapy*
chemical_list: D016376:Oligonucleotides, Antisense
keywords: Duchenne muscular dystrophy; Fukuyama congenital muscular dystrophy; Miyoshi myopathy; antisense therapy; dysferlinopathy; exon skipping; limb-girdle muscular dystrophy 2B; spinal muscular atrophy; splice modulation