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.
- 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].
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.