2. Academic Validation
  3. Loss of MAFB Function in Humans and Mice Causes Duane Syndrome, Aberrant Extraocular Muscle Innervation, and Inner-Ear Defects

Loss of MAFB Function in Humans and Mice Causes Duane Syndrome, Aberrant Extraocular Muscle Innervation, and Inner-Ear Defects

  • Am J Hum Genet. 2016 Jun 2;98(6):1220-1227. doi: 10.1016/j.ajhg.2016.03.023.
Jong G Park 1,  Max A Tischfield 2,  Alicia A Nugent 3,  Long Cheng 4,  Silvio Alessandro Di Gioia 2,  Wai-Man Chan 5,  Gail Maconachie 6,  Thomas M Bosley 7,  C Gail Summers 8,  David G Hunter 9,  Caroline D Robson 10,  Irene Gottlob 6,  Elizabeth C Engle 11
Affiliations

Affiliations

  • 1 Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA; Department of Neurology, Boston Children's Hospital, Boston, MA 02115, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, Boston, MA 02115, USA; Duke University School of Medicine, Durham, NC 27710, USA.
  • 2 Department of Neurology, Boston Children's Hospital, Boston, MA 02115, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA.
  • 3 Department of Neurology, Boston Children's Hospital, Boston, MA 02115, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA; Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA.
  • 4 Department of Neurology, Boston Children's Hospital, Boston, MA 02115, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, Boston, MA 02115, USA.
  • 5 Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA; Department of Neurology, Boston Children's Hospital, Boston, MA 02115, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, Boston, MA 02115, USA.
  • 6 Ulverscroft Eye Unit, University of Leicester, Leicester LE2 7LX, UK; Department of Neuroscience, Psychology, and Behavior, University of Leicester, Leicester LE2 7LX, UK.
  • 7 Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD 21287, USA.
  • 8 Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455, USA; Department of Pediatrics, University of Minnesota, Minneapolis, MN 55455, USA.
  • 9 Department of Ophthalmology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Ophthalmology, Harvard Medical School, Boston, MA 02115, USA.
  • 10 Department of Radiology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Radiology, Harvard Medical School, Boston, MA 02115, USA.
  • 11 Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA; Department of Neurology, Boston Children's Hospital, Boston, MA 02115, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, Boston, MA 02115, USA; Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA; Department of Ophthalmology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Ophthalmology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA. Electronic address: elizabeth.engle@childrens.harvard.edu.
PMID: 27181683 DOI: 10.1016/j.ajhg.2016.03.023
Abstract

Duane retraction syndrome (DRS) is a congenital eye-movement disorder defined by limited outward gaze and retraction of the eye on attempted inward gaze. Here, we report on three heterozygous loss-of-function MAFB mutations causing DRS and a dominant-negative MAFB mutation causing DRS and deafness. Using genotype-phenotype correlations in humans and Mafb-knockout mice, we propose a threshold model for variable loss of MAFB function. Postmortem studies of DRS have reported abducens nerve hypoplasia and aberrant innervation of the lateral rectus muscle by the oculomotor nerve. Our studies in mice now confirm this human DRS pathology. Moreover, we demonstrate that selectively disrupting abducens nerve development is sufficient to cause secondary innervation of the lateral rectus muscle by aberrant oculomotor nerve branches, which form at developmental decision regions close to target extraocular muscles. Thus, we present evidence that the primary cause of DRS is failure of the abducens nerve to fully innervate the lateral rectus muscle in early development.

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