1. Academic Validation
  2. Glutaminase Deficiency Caused by Short Tandem Repeat Expansion in GLS

Glutaminase Deficiency Caused by Short Tandem Repeat Expansion in GLS

  • N Engl J Med. 2019 Apr 11;380(15):1433-1441. doi: 10.1056/NEJMoa1806627.
André B P van Kuilenburg 1 Maja Tarailo-Graovac 1 Phillip A Richmond 1 Britt I Drögemöller 1 Mahmoud A Pouladi 1 René Leen 1 Koroboshka Brand-Arzamendi 1 Doreen Dobritzsch 1 Egor Dolzhenko 1 Michael A Eberle 1 Bruce Hayward 1 Meaghan J Jones 1 Farhad Karbassi 1 Michael S Kobor 1 Janet Koster 1 Daman Kumari 1 Meng Li 1 Julia MacIsaac 1 Cassandra McDonald 1 Judith Meijer 1 Charlotte Nguyen 1 Indhu-Shree Rajan-Babu 1 Stephen W Scherer 1 Bernice Sim 1 Brett Trost 1 Laura A Tseng 1 Marjolein Turkenburg 1 Joke J F A van Vugt 1 Jan H Veldink 1 Jagdeep S Walia 1 Youdong Wang 1 Michel van Weeghel 1 Galen E B Wright 1 Xiaohong Xu 1 Ryan K C Yuen 1 Jinqiu Zhang 1 Colin J Ross 1 Wyeth W Wasserman 1 Michael T Geraghty 1 Saikat Santra 1 Ronald J A Wanders 1 Xiao-Yan Wen 1 Hans R Waterham 1 Karen Usdin 1 Clara D M van Karnebeek 1
Affiliations

Affiliation

  • 1 From Amsterdam University Medical Centers, University of Amsterdam, Departments of Clinical Chemistry, Pediatrics, and Clinical Genetics, Emma Children's Hospital, Amsterdam Gastroenterology and Metabolism (A.B.P.K., R.L., J.K., J. Meijer, L.A.T., M.T., M.W., R.J.A.W., H.R.W., C.D.M.K.), and United for Metabolic Diseases (A.B.P.K., R.J.A.W., H.R.W., C.D.M.K.), Amsterdam, and the Department of Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht (J.J.F.A.V., J.H.V.), and the Project MinE ALS Sequencing Consortium (J.J.F.A.V., J.H.V.), Utrecht - all in the Netherlands; the Departments of Biochemistry and Molecular Biology and Medical Genetics, Cumming School of Medicine, and Alberta Children's Hospital Research Institute, University of Calgary, Calgary (M.T.-G.), Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute (P.A.R., M.J.J., M.S.K., J. MacIsaac, W.W.W., C.D.M.K.), the Faculty of Pharmaceutical Sciences (B.I.D., G.E.B.W., C.J.R.), and the Departments of Medical Genetics (C.M., I.-S.R.-B., W.W.W.) and Pediatrics (C.D.M.K.), University of British Columbia, Vancouver, the Zebrafish Centre for Advanced Drug Discovery, St. Michael's Hospital and University of Toronto (K.B.-A., F.K., M.L., Y.W., X.-Y.W.), the Centre for Applied Genomics, Genetics and Genome Biology, the Hospital for Sick Children (C.N., S.W.S., B.T., R.K.C.Y.), and the Department of Molecular Genetics (C.N., S.W.S., R.K.C.Y.), the McLaughlin Centre (S.W.S.), and the Departments of Medicine, Physiology, and Laboratory Medicine and Pathobiology, Institute of Medical Science (X.-Y.W.), University of Toronto, Toronto, and the Division of Medical Genetics, Department of Pediatrics, Children's Hospital Eastern Ontario, University of Ottawa, Ottawa (J.S.W., M.T.G.) - all in Canada; the Departments of Medicine and Physiology, National University of Singapore (M.A.P.), and the Translational Laboratory in Genetic Medicine, Agency for Science, Technology, and Research (M.A.P., B.S., X.X., J.Z.) - both in Singapore; Uppsala University, Department of Chemistry-Biomedical Center, Uppsala, Sweden (D.D.); Illumina, San Diego, CA (E.D., M.A.E.); Gene Structure and Disease Section, Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD (B.H., D.K., K.U.); and the Department of Clinical Inherited Metabolic Disorders, Birmingham Children's Hospital, Birmingham, United Kingdom (S.S.).
Abstract

We report an inborn error of metabolism caused by an expansion of a GCA-repeat tract in the 5' untranslated region of the gene encoding Glutaminase (GLS) that was identified through detailed clinical and biochemical phenotyping, combined with whole-genome Sequencing. The expansion was observed in three unrelated patients who presented with an early-onset delay in overall development, progressive ataxia, and elevated levels of glutamine. In addition to ataxia, one patient also showed cerebellar atrophy. The expansion was associated with a relative deficiency of GLS messenger RNA transcribed from the expanded allele, which probably resulted from repeat-mediated chromatin changes upstream of the GLS repeat. Our discovery underscores the importance of careful examination of regions of the genome that are typically excluded from or poorly captured by exome Sequencing.

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