{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,25]],"date-time":"2026-09-25T22:53:55Z","timestamp":1790376835212,"version":"4.1.0"},"reference-count":15,"publisher":"BMJ","issue":"1","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2026,1,2]]},"published-print":{"date-parts":[[2026,1]]},"abstract":"<jats:p>\n                    Signal transducer and activator of transcription 3 (STAT3) gain-of-function (GOF) syndrome is a rare genetic immune dysregulation disorder that typically presents in infancy with autoimmunity, lymphoproliferation, susceptibility to infections and growth delay. We report a case of a man in his late 20s admitted to hospital multiple times with abdominal pain, fever and raised C-reactive protein, where imaging revealed progressive mesenteric lymphadenopathy. A definitive diagnosis remained elusive until genetic analysis highlighted a GOF heterozygous mutation in the S\n                    <jats:italic>TAT3<\/jats:italic>\n                    gene. Targeted therapy with Janus kinase inhibitor (tofacitinib) led to significant clinical and radiological improvement. This case underscores the value of a multidisciplinary assessment and early genome sequencing in diagnosing unexplained systemic manifestations, offering promising prospects for more effective management through targeted therapies.\n                  <\/jats:p>","DOI":"10.1136\/bcr-2025-271007","type":"journal-article","created":{"date-parts":[[2026,1,19]],"date-time":"2026-01-19T16:20:16Z","timestamp":1768839616000},"page":"e271007","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":1,"title":["STAT3 gain-of-function mutation presenting with adult-onset recurrent abdominal pain, fever and lymphadenopathy, managed by JAK inhibitor therapy"],"prefix":"10.1136","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6770-5425","authenticated-orcid":false,"given":"Rofaida","family":"Desoki","sequence":"first","affiliation":[{"name":"Gastroenterology Department, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK"},{"name":"Department of Genetics, Faculty of Medicine, Alexandria University, Alexandria, Egypt"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0008-3137-9953","authenticated-orcid":false,"given":"Stephany","family":"Barreda","sequence":"additional","affiliation":[{"name":"Gastroenterology Department, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Samir","family":"Khwaja","sequence":"additional","affiliation":[{"name":"Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Miles","family":"Parkes","sequence":"additional","affiliation":[{"name":"Gastroenterology Department, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2026,1,19]]},"reference":[{"key":"2026062608101257000_19.1.e271007.1","doi-asserted-by":"publisher","DOI":"10.1182\/blood-2014-09-602763"},{"key":"2026062608101257000_19.1.e271007.2","doi-asserted-by":"publisher","DOI":"10.1089\/jir.2014.0225"},{"key":"2026062608101257000_19.1.e271007.3","doi-asserted-by":"publisher","DOI":"10.1016\/j.cytogfr.2016.05.001"},{"key":"2026062608101257000_19.1.e271007.4","doi-asserted-by":"crossref","DOI":"10.3389\/fped.2022.770077","article-title":"STAT3 gain-of-function syndrome","volume":"10","author":"Vogel","year":"2022","journal-title":"Front Pediatr"},{"key":"2026062608101257000_19.1.e271007.5","doi-asserted-by":"crossref","unstructured":"Pan M , Kurtz J . Novel STAT3 variant causing infantile-onset autoimmune disease. Front Med 2023;10. doi:10.3389\/fmed.2023.1251088","DOI":"10.3389\/fmed.2023.1251088"},{"key":"2026062608101257000_19.1.e271007.6","doi-asserted-by":"publisher","DOI":"10.1016\/j.jaci.2022.09.002"},{"key":"2026062608101257000_19.1.e271007.7","doi-asserted-by":"publisher","DOI":"10.1016\/j.jaci.2018.07.020"},{"key":"2026062608101257000_19.1.e271007.8","doi-asserted-by":"crossref","DOI":"10.3389\/fimmu.2024.1400348","article-title":"JAK inhibitors to treat STAT3 gain-of-function: a single-center report and literature review","volume":"15","author":"Atschekzei","year":"2024","journal-title":"Front Immunol"},{"key":"2026062608101257000_19.1.e271007.9","doi-asserted-by":"crossref","first-page":"218","DOI":"10.37349\/ei.2024.00138","article-title":"Targeted treatments for immune dysregulation in inborn errors of immunity","volume":"4","author":"Makkoukdji","year":"2024","journal-title":"Explor Immunol"},{"key":"2026062608101257000_19.1.e271007.10","doi-asserted-by":"crossref","first-page":"105","DOI":"10.31138\/mjr.31.1.105","article-title":"Therapeutic targeting of JAKs: from hematology to rheumatology and from the first to the second generation of JAK inhibitors","volume":"31","author":"Bertsias","year":"2020","journal-title":"Mediterr J Rheumatol"},{"key":"2026062608101257000_19.1.e271007.11","doi-asserted-by":"crossref","first-page":"761","DOI":"10.1007\/s40265-018-0908-4","article-title":"Baricitinib: A Review in Rheumatoid Arthritis","volume":"78","author":"Al-Salama","year":"2018","journal-title":"Drugs"},{"key":"2026062608101257000_19.1.e271007.12","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1080\/14728214.2018.1445718","article-title":"Emerging drugs for the treatment of Myelofibrosis","volume":"23","author":"Shreenivas","year":"2018","journal-title":"Expert Opin Emerg Drugs"},{"key":"2026062608101257000_19.1.e271007.13","doi-asserted-by":"publisher","DOI":"10.1016\/j.jaci.2023.10.018"},{"key":"2026062608101257000_19.1.e271007.14","doi-asserted-by":"crossref","DOI":"10.3390\/biom12101450","article-title":"STAT3 Inhibitors: A Novel Insight for Anticancer Therapy of Pancreatic Cancer","volume":"12","author":"Li","year":"2022","journal-title":"Biomolecules"},{"key":"2026062608101257000_19.1.e271007.15","doi-asserted-by":"crossref","first-page":"846","DOI":"10.1097\/CAD.0000000000000783","article-title":"C188-9, a small-molecule STAT3 inhibitor, exerts an antitumor effect on head and neck squamous cell carcinoma","volume":"30","author":"Di","year":"2019","journal-title":"Anticancer Drugs"}],"container-title":["BMJ Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bcr-2025-271007","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,26]],"date-time":"2026-06-26T15:21:04Z","timestamp":1782487264000},"score":1,"resource":{"primary":{"URL":"https:\/\/casereports.bmj.com\/lookup\/doi\/10.1136\/bcr-2025-271007"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1]]},"references-count":15,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2026,1,19]]},"published-print":{"date-parts":[[2026,1]]}},"alternative-id":["10.1136\/bcr-2025-271007"],"URL":"https:\/\/doi.org\/10.1136\/bcr-2025-271007","relation":{},"ISSN":["1757-790X"],"issn-type":[{"value":"1757-790X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,1]]}}}