Abstract
D.I.4 Patient fibroblast functional complementation studies: A valuable tool in the identification of novel Walker–Warburg syndrome disease genes
Neuromuscular disorders : NMD, Vol.22(9-10), pp.805-805
10/2012
DOI: 10.1016/j.nmd.2012.06.014
Abstract
Walker–Warburg syndrome (WWS) is clinically defined as congenital muscular dystrophy accompanied by a variety of brain and eye malformations. It represents the most severe clinical phenotype in a spectrum of alpha-dystroglycan posttranslational processing abnormalities, which share a defect in laminin binding glycan synthesis. Although six WWS causing genes have been described, only half of all patients can currently be diagnosed genetically. We now report that skin fibroblasts can be utilized to analyze the status of alpha-dystroglycan functional glycosylation, which is lost or reduced in dystroglycanopathy patient cells. To identify and validate the disease causing genes in dystroglycanopathy patients we developed a functional complementation assay based on adenoviral gene transfer into patient fibroblasts. We also examined cell fusion complementation assays using fibroblasts from undiagnosed WWS individuals and identified five novel complementation groups. Further evaluation of one group by linkage analysis and targeted sequencing identified recessive mutations in the isoprenoid synthase domain containing (ISPD) gene. Confirmation of the pathogenicity of the identified ISPD mutations was demonstrated by complementation of fibroblasts with wild-type ISPD. Finally, we provide conclusive genetic and biochemical evidence that recessive mutations in ISPD abolish the initial step in laminin binding glycan synthesis by disrupting dystroglycan O-mannosylation. Further studies are needed to determine how defects in ISPD influence protein O-mannosylation, as this is the first WWS gene without proposed glycosyltransferase activity and direct role in α-DG glycosylation. This establishes a novel mechanism for WWS pathophysiology.
Details
- Title: Subtitle
- D.I.4 Patient fibroblast functional complementation studies: A valuable tool in the identification of novel Walker–Warburg syndrome disease genes
- Creators
- T Willer - Howard Hughes Medical Institute, Department of Molecular Physiology and Biophysics, Department of Neurology, Department of Internal Medicine, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, United StatesH Lee - David Geffen School of Medicine, University of California, Department of Human Genetics, Los Angeles, United StatesM Lommel - Centre for Organismal Studies, Department of Cell Chemistry, University of Heidelberg, Heidelberg, GermanyT Yoshida-Moriguchi - Howard Hughes Medical Institute, Department of Molecular Physiology and Biophysics, Department of Neurology, Department of Internal Medicine, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, United StatesD Beltran Valero de Bernabe - Howard Hughes Medical Institute, Department of Molecular Physiology and Biophysics, Department of Neurology, Department of Internal Medicine, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, United StatesD Venzke - Howard Hughes Medical Institute, Department of Molecular Physiology and Biophysics, Department of Neurology, Department of Internal Medicine, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, United StatesS Cirak - Dubowitz Neuromuscular Centre, Division of Neuroscience, Institute of Child Health & Great Ormond Street Hospital for Children, London, United KingdomH Schachter - Molecular Structure and Function, The Hospital for Sick Children, Toronto, CanadaJ Vajsar - Division of Neurology, The Hospital for Sick Children, Toronto, CanadaT Voit - University Pierre et Marie Curie, UM 76, Inserm U974, CNRS, UMR 7215, AP-HP, Institute of Myology, Paris, FranceF Muntoni - University of Iowa Roy J. and Lucille A. Carver College of Medicine, Department of Pediatrics, Department of Neurology, Iowa, United StatesS Strahl - Centre for Organismal Studies, Department of Cell Chemistry, University of Heidelberg, Heidelberg, GermanyK.D Mathews - University of Iowa Roy J. and Lucille A. Carver College of Medicine, Department of Pediatrics, Department of Neurology, Iowa, United StatesS.F Nelson - David Geffen School of Medicine, University of California, Department of Human Genetics, Los Angeles, United StatesS.A Moore - University of Iowa Roy J. and Lucille A. Carver College of Medicine, Department of Pathology, Iowa, United StatesK.P Campbell - Howard Hughes Medical Institute, Department of Molecular Physiology and Biophysics, Department of Neurology, Department of Internal Medicine, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, United States
- Resource Type
- Abstract
- Publication Details
- Neuromuscular disorders : NMD, Vol.22(9-10), pp.805-805
- Publisher
- Elsevier B.V
- DOI
- 10.1016/j.nmd.2012.06.014
- ISSN
- 0960-8966
- eISSN
- 1873-2364
- Language
- English
- Date published
- 10/2012
- Academic Unit
- Pathology; Stead Family Department of Pediatrics; Iowa Neuroscience Institute; Neurology; Molecular Physiology and Biophysics; Neurology (Pediatrics)
- Record Identifier
- 9984020717002771
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