2. Academic Validation
  3. Bi-allelic CCDC47 Variants Cause a Disorder Characterized by Woolly Hair, Liver Dysfunction, Dysmorphic Features, and Global Developmental Delay

Bi-allelic CCDC47 Variants Cause a Disorder Characterized by Woolly Hair, Liver Dysfunction, Dysmorphic Features, and Global Developmental Delay

  • Am J Hum Genet. 2018 Nov 1;103(5):794-807. doi: 10.1016/j.ajhg.2018.09.014.
Marie Morimoto 1,  Helen Waller-Evans 2,  Zineb Ammous 3,  Xiaofei Song 4,  Kevin A Strauss 5,  Davut Pehlivan 4,  Claudia Gonzaga-Jauregui 6,  Erik G Puffenberger 5,  Charles R Holst 7,  Ender Karaca 4,  Karlla W Brigatti 5,  Emily Maguire 2,  Zeynep H Coban-Akdemir 4,  Akiko Amagata 7,  C Christopher Lau 1,  Xenia Chepa-Lotrea 1,  Ellen Macnamara 1,  Tulay Tos 8,  Sedat Isikay 9,  Michele Nehrebecky 1,  John D Overton 6,  Matthew Klein 7,  Thomas C Markello 1,  Jennifer E Posey 4,  David R Adams 10,  Emyr Lloyd-Evans 2,  James R Lupski 11,  William A Gahl 10,  May Christine V Malicdan 12
Affiliations

Affiliations

  • 1 National Institutes of Health Undiagnosed Diseases Program, Common Fund, Office of the Director, National Institutes of Health, Bethesda, MD 20892, USA.
  • 2 School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK.
  • 3 The Community Health Clinic, Topeka, IN 46571, USA.
  • 4 Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
  • 5 Clinic for Special Children, Strasburg, PA 17579, USA.
  • 6 Regeneron Genetics Center, Regeneron Pharmaceuticals Inc., Tarrytown, NY 10591, USA.
  • 7 BioElectron Technology Corporation, Mountain View, CA 94043, USA.
  • 8 Department of Medical Genetics, Dr. Sami Ulus Research and Training Hospital of Women's and Children's Health and Diseases, Ankara 06080, Turkey.
  • 9 Department of Physiotherapy and Rehabilitation, Hasan Kalyoncu University, School of Health Sciences, Gaziantep 27000, Turkey.
  • 10 National Institutes of Health Undiagnosed Diseases Program, Common Fund, Office of the Director, National Institutes of Health, Bethesda, MD 20892, USA; Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA; Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.
  • 11 Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA; Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA; Texas Children's Hospital, Houston, TX 77030, USA.
  • 12 National Institutes of Health Undiagnosed Diseases Program, Common Fund, Office of the Director, National Institutes of Health, Bethesda, MD 20892, USA; Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA; Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address: maychristine.malicdan@nih.gov.
PMID: 30401460 DOI: 10.1016/j.ajhg.2018.09.014
Abstract

CA2+ signaling is vital for various cellular processes including synaptic vesicle exocytosis, muscle contraction, regulation of secretion, gene transcription, and cellular proliferation. The endoplasmic reticulum (ER) is the largest intracellular CA2+ store, and dysregulation of ER CA2+ signaling and homeostasis contributes to the pathogenesis of various complex disorders and Mendelian disease traits. We describe four unrelated individuals with a complex multisystem disorder characterized by woolly hair, liver dysfunction, pruritus, dysmorphic features, hypotonia, and global developmental delay. Through whole-exome Sequencing and family-based genomics, we identified bi-allelic variants in CCDC47 that encodes the CA2+-binding ER transmembrane protein CCDC47. CCDC47, also known as calumin, has been shown to bind CA2+ with low affinity and high capacity. In mice, loss of Ccdc47 leads to embryonic lethality, suggesting that Ccdc47 is essential for early development. Characterization of cells from individuals with predicted likely damaging alleles showed decreased CCDC47 mRNA expression and protein levels. In vitro cellular experiments showed decreased total ER CA2+ storage, impaired CA2+ signaling mediated by the IP3R CA2+ release channel, and reduced ER CA2+ refilling via store-operated CA2+ entry. These results, together with the previously described role of CCDC47 in CA2+ signaling and development, suggest that bi-allelic loss-of-function variants in CCDC47 underlie the pathogenesis of this multisystem disorder.

Keywords

CCDC47; Ca(2+) signaling; calumin; coiled-coil domain containing 47; endoplasmic reticulum; rare disease; store-operated Ca(2+) entry; undiagnosed disease; whole-exome sequencing.

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