DNA Polymerase Epsilon Deficiency Causes IMAGe Syndrome with Variable Immunodeficiency

  • Am J Hum Genet. 2018 Dec 6;103(6):1038-1044. doi: 10.1016/j.ajhg.2018.10.024.
Clare V Logan  1 Jennie E Murray  2 David A Parry  1 Andrea Robertson  1 Roberto Bellelli  3 Žygimantė Tarnauskaitė  1 Rachel Challis  4 Louise Cleal  4 Valerie Borel  3 Adeline Fluteau  1 Javier Santoyo-Lopez  5 SGP Consortium Tim Aitman  6 Inês Barroso  7 Donald Basel  8 Louise S Bicknell  9 Himanshu Goel  10 Hao Hu  11 Chad Huff  11 Michele Hutchison  12 Caroline Joyce  13 Rachel Knox  14 Amy E Lacroix  15 Sylvie Langlois  16 Shawn McCandless  17 Julie McCarrier  8 Kay A Metcalfe  18 Rose Morrissey  19 Nuala Murphy  20 Irène Netchine  21 Susan M O'Connell  20 Ann Haskins Olney  15 Nandina Paria  22 Jill A Rosenfeld  23 Mark Sherlock  24 Erin Syverson  8 Perrin C White  25 Carol Wise  26 Yao Yu  11 Margaret Zacharin  27 Indraneel Banerjee  28 Martin Reijns  1 Michael B Bober  29 Robert K Semple  30 Simon J Boulton  3 Jonathan J Rios  26 Andrew P Jackson  31
Affiliations
  • 1. MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK.
  • 2. MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK; South East Scotland Clinical Genetics Service, Western General Hospital, Edinburgh EH4 2XU, UK. Electronic address: [email protected].
  • 3. The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.
  • 4. MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK; South East Scotland Clinical Genetics Service, Western General Hospital, Edinburgh EH4 2XU, UK.
  • 5. Edinburgh Genomics Clinical Division, University of Edinburgh, The Roslin Institute, Edinburgh EH25 9RG, UK.
  • 6. MRC Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK.
  • 7. Wellcome Sanger Institute, Cambridge CB10 1SA, UK.
  • 8. Medical College of Wisconsin from Children's Hospital of Wisconsin, Milwaukee, WI 53226, USA.
  • 9. Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin 9016, New Zealand.
  • 10. Hunter Genetics, Waratah, NSW 2305, Australia; University of Newcastle, Callaghan, NSW 2308, Australia.
  • 11. Department of Epidemiology, MD Anderson Cancer Center, Houston, TX 77030, USA.
  • 12. Department of Pediatrics, University of Arkansas, Little Rock, AR 72205, USA.
  • 13. Department of Clinical Biochemistry, Cork University Hospital, Cork, Ireland.
  • 14. MRC Metabolic Diseases Unit, University of Cambridge, Cambridge CB2 0QQ, UK.
  • 15. University of Nebraska Medical Centre, Omaha, NE 68918, USA.
  • 16. Department of Medical Genetics, The University of British Columbia, Vancouver, BC V6H 3N1, Canada.
  • 17. Pediatric Genetics, UH Cleveland Medical Center, Cleveland, OH 44106, USA.
  • 18. Manchester Centre for Genomic Medicine, Manchester University NHS Foundation Trust and Institute of Human Development, University of Manchester, Manchester M13 9WL, UK.
  • 19. Department of Paediatrics and Child Health, Cork University Hospital, Cork, Ireland.
  • 20. UCD School of Medicine, Children's University Hospital, Temple St, Dublin, Ireland.
  • 21. Sorbonne Université, INSERM, UMR_S 938, APHP, Hospital Trousseau, 75012 Paris, France.
  • 22. Sarah M. and Charles E. Seay Center for Musculoskeletal Research, Texas Scottish Rite Hospital for Children, Dallas, TX 75219, USA.
  • 23. Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
  • 24. Department of Endocrinology, Beaumont Hospital, Dublin, Ireland.
  • 25. Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
  • 26. Sarah M. and Charles E. Seay Center for Musculoskeletal Research, Texas Scottish Rite Hospital for Children, Dallas, TX 75219, USA; Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Orthopaedic Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
  • 27. Division of Medicine, Royal Children's Hospital, Melbourne, VIC 3052, Australia.
  • 28. Department of Paediatric Endocrinology, Royal Manchester Children's Hospital, Manchester Academic Health Science Centre, Manchester M13 9WU, UK.
  • 29. Nemours-Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA.
  • 30. MRC Metabolic Diseases Unit, University of Cambridge, Cambridge CB2 0QQ, UK; Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, UK.
  • 31. MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK. Electronic address: [email protected].
Abstract

During genome replication, polymerase epsilon (Pol ε) acts as the major leading-strand DNA Polymerase. Here we report the identification of biallelic mutations in POLE, encoding the Pol ε catalytic subunit POLE1, in 15 individuals from 12 families. Phenotypically, these individuals had clinical features closely resembling IMAGe syndrome (intrauterine growth restriction [IUGR], metaphyseal dysplasia, adrenal hypoplasia congenita, and genitourinary anomalies in males), a disorder previously associated with gain-of-function mutations in CDKN1C. POLE1-deficient individuals also exhibited distinctive facial features and variable immune dysfunction with evidence of lymphocyte deficiency. All subjects shared the same intronic variant (c.1686+32C>G) as part of a common haplotype, in combination with different loss-of-function variants in trans. The intronic variant alters splicing, and together the biallelic mutations lead to cellular deficiency of Pol ε and delayed S-phase progression. In summary, we establish POLE as a second gene in which mutations cause IMAGe syndrome. These findings add to a growing list of disorders due to mutations in DNA replication genes that manifest growth restriction alongside adrenal dysfunction and/or immunodeficiency, consolidating these as replisome phenotypes and highlighting a need for future studies to understand the tissue-specific development roles of the encoded proteins.

Keywords
DNA replication; IMAGe syndrome; adrenal failure; cell cycle; growth; immunodeficiency; microcephaly; polymerase epsilon.