first_page settings Order Article Reprints Open AccessArticle Three-Country Snapshot of Ornithine Transcarbamylase Deficiency by Berna Seker Yilmaz 1,* [ORCID] , Julien Baruteau 1,2,3 [ORCID] , Nur Arslan 4 [ORCID] , Halil Ibrahim Aydin 5, Magalie Barth 6, Ayse Ergul Bozaci 7 [ORCID] , Anais Brassier 8, Ebru Canda 9, Aline Cano 10, Efstathia Chronopoulou 11, Grainne M. Connolly 12, Lena Damaj 13, Charlotte Dawson 14, Dries Dobbelaere 15, Claire Douillard 15, Fatma Tuba Eminoglu 16, Sahin Erdol 17, Melike Ersoy 18, Sherry Fang 3, François Feillet 19, add Show full author list 1 Genetics and Genomic Medicine Department, Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK 2 National Institute of Health Research Great Ormond Street Biomedical Research Centre, London WC1N 1EH, UK 3 Metabolic Medicine Department, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK 4 Paediatric Metabolic Medicine Department, Dokuz Eylul University Faculty of Medicine, Izmir 35340, Turkey 5 Paediatric Metabolic Medicine Department, Baskent University Faculty of Medicine, Ankara 06490, Turkey 6 Centre de Référence des Maladies Héréditaires du Métabolisme, CHU Angers, 4 rue Larrey, CEDEX 9, 49933 Angers, France 7 Paediatric Metabolic Medicine Department, Diyarbakir Children’s Hospital, Diyarbakir 21100, Turkey 8 Reference Center for Inborn Errors of Metabolism, Necker University Hospital, APHP and University of Paris Cité, 75015 Paris, France 9 Paediatric Metabolic Medicine Department, Ege University Faculty of Medicine, Izmir 35100, Turkey 10 Reference Center of Inherited Metabolic Disorders, Timone Enfants Hospital, 264 rue Saint-Pierre, 13005 Marseille, France 11 Department of Inherited Metabolic Disease, Division of Women’s and Children’s Services, University Hospitals Bristol NHS Foundation Trust, Bristol BS1 3NU, UK 12 Belfast Health and Social Care Trust, Belfast BT9 7AB, UK 13 Centre de Compétence Maladies Héréditaires du Métabolisme, CHU Hôpital Sud, CEDEX 2, 35203 Rennes, France 14 Metabolic Medicine Department, University Hospitals Birmingham NHS Foundation Trust, Birmingham B15 2GW, UK 15 Medical Reference Center for Inherited Metabolic Diseases, Jeanne de Flandre University Hospital and RADEME Research Team for Rare Metabolic and Developmental Diseases, EA 7364 CHRU Lille, 59000 Lille, France 16 Paediatric Metabolic Medicine Department, Ankara University Faculty of Medicine, Ankara 06080, Turkey 17 Paediatric Metabolic Medicine Department, Uludag University Faculty of Medicine, Bursa 16059, Turkey 18 Paediatric Metabolic Medicine Department, Dr Sadi Konuk Reseach & Training Hospital, Istanbul 34450, Turkey 19 Centre de Référence des Maladies Métaboliques de Nancy, CHU Brabois Enfants, 5 Rue du Morvan, 54500 Vandœuvre-lès-Nancy, France 20 Paediatric Metabolic Medicine Department, Istanbul University Istanbul Faculty of Medicine, Istanbul 34093, Turkey 21 Paediatric Metabolic Medicine Department, Cengiz Gokcek Children’s Hospital, Gaziantep 27010, Turkey 22 Centre de Référence des Maladies Rares du Métabolisme, Hôpital des Enfants—CHU Toulouse, 330 Avenue de Grande-Bretagne, CEDEX 9, 31059 Toulouse, France 23 Paediatric Metabolic Medicine Department, Gazi University Faculty of Medicine, Ankara 06500, Turkey 24 Paediatric Metabolic Medicine Department, Konya City Hospital, Konya 42020, Turkey 25 Paediatric Metabolic Medicine Department, Erciyes University Faculty of Medicine, Kayseri 38030, Turkey 26 Paediatric Metabolic Medicine Department, Ankara Yildirim Beyazit University Faculty of Medicine, Ankara 06800, Turkey 27 Paediatric Metabolic Medicine Department, Osmangazi University Faculty of Medicine, Eskisehir 26480, Turkey 28 Paediatric Metabolic Medicine Department, Cukurova University Faculty of Medicine, Adana 01250, Turkey 29 Paediatric Metabolic Medicine Department, Faculty of Medicine, Izmir Katip Celebi University, Izmir 35620, Turkey 30 MMDN, University Montpellier, EPHE, INSERM, 34090 Montpellier, France 31 Expert Center for Metabolic and Neurogenetic Diseases, Centre Hospitalier Universitaire (CHU), 34090 Montpellier, France 32 Evelina Children’s Hospital, Guy’s and St Thomas’ NHS Foundation Trust, London SE1 7EH, UK 33 Royal Belfast Hospital for Sick Children, Belfast BT12 6BA, UK 34 Paediatric Metabolic Medicine Department, Marmara University Faculty of Medicine, Istanbul 34854, Turkey 35 Guy’s and St Thomas’ NHS Foundation Trust, London SE1 7EH, UK 36 Paediatric Metabolic Medicine Department, Antalya Training and Research Hospital, Antalya 07100, Turkey 37 Birmingham Women’s and Children’s Hospital NHS Foundation Trust, Birmingham B4 6NH, UK 38 Adult Inherited Metabolic Diseases, Salford Royal NHS Foundation Trust, Salford M6 8HD, UK 39 Paediatric Metabolic Medicine Department, Kocaeli University Faculty of Medicine, Kocaeli 41380, Turkey 40 Paediatric Metabolic Medicine Department, Hacettepe University Faculty of Medicine, Ankara 06230, Turkey 41 Paediatric Metabolic Medicine Department, Istanbul University-Cerrahpasa Faculty of Medicine, Istanbul 34096, Turkey remove Hide full affiliation list * Author to whom correspondence should be addressed. Life 2022, 12(11), 1721; https://doi.org/10.3390/life12111721 Submission received: 22 September 2022 / Revised: 24 October 2022 / Accepted: 25 October 2022 / Published: 27 October 2022 (This article belongs to the Topic Rare Diseases Are Not Rare) Download keyboard_arrow_down Browse Figures Versions Notes Abstract X-linked ornithine transcarbamylase deficiency (OTCD) is the most common urea cycle defect. The disease severity ranges from asymptomatic carrier state to severe neonatal presentation with hyperammonaemic encephalopathy. We audited the diagnosis and management of OTCD, using an online 12-question-survey that was sent to 75 metabolic centres in Turkey, France and the UK. Thirty-nine centres responded and 495 patients were reported in total. A total of 208 French patients were reported, including 71 (34%) males, 86 (41%) symptomatic and 51 (25%) asymptomatic females. Eighty-five Turkish patients included 32 (38%) males, 39 (46%) symptomatic and 14 (16%) asymptomatic females. Out of the 202 UK patients, 66 (33%) were male, 83 (41%) asymptomatic and 53 (26%) symptomatic females. A total of 19%, 12% and 7% of the patients presented with a neonatal-onset phenotype in France, Turkey and the UK, respectively. Vomiting, altered mental status and encephalopathy were the most common initial symptoms in all three countries. While 69% in France and 79% in Turkey were receiving protein restriction, 42% were on a protein-restricted diet in the UK. A total of 76%, 47% and 33% of patients were treated with ammonia scavengers in Turkey, France and the UK, respectively. The findings of our audit emphasize the differences and similarities in manifestations and management practices in three countries. Keywords: ornithine transcarbamylase deficiency; hyperammonaemia; neonatal-onset; late-onset; asymptomatic; protein restriction; ammonia scavengers; liver transplantation