{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T12:00:44Z","timestamp":1781092844177,"version":"3.54.1"},"reference-count":6,"publisher":"BMJ","issue":"6","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2026,5,4]]},"published-print":{"date-parts":[[2026,6]]},"abstract":"<jats:p>Birt\u2013Hogg\u2013Dub\u00e9 (BHD) syndrome is a rare autosomal dominant disorder characterised by pulmonary cysts, recurrent spontaneous pneumothorax, cutaneous lesions and an increased risk of renal tumours. Pulmonary manifestations often precede other features, leading to delayed recognition. We report the case of a non-smoking male in his early 60s who presented with recurrent left-sided spontaneous pneumothorax and exertional dyspnoea. Cutaneous examination revealed multiple acrochordons over the neck. Chest imaging demonstrated pneumothorax, and high-resolution CT of the thorax showed a left upper lobe bulla with multiple bilateral thin-walled pulmonary cysts with basal predominance. The patient underwent bullectomy and surgical pleurodesis. Histopathology revealed thin-walled cysts lined by normal respiratory epithelium without smooth muscle proliferation, and HMB-45 immunostaining was negative, excluding lymphangioleiomyomatosis. Serum alpha-1 antitrypsin levels were normal. Genetic analysis identified a heterozygous pathogenic frameshift variant (c.1285delC) in the FLCN gene, confirming the diagnosis of BHD syndrome. The postoperative course was uneventful, and renal surveillance and family counselling were initiated. This case underscores the importance of considering BHD syndrome in non-smokers presenting with recurrent pneumothorax and cystic lung disease, as early diagnosis facilitates appropriate surveillance and genetic evaluation.<\/jats:p>","DOI":"10.1136\/bcr-2026-273149","type":"journal-article","created":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T11:05:20Z","timestamp":1781089520000},"page":"e273149","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["Birt\u2013Hogg\u2013Dub\u00e9 syndrome: a hidden genetic cause of recurrent pneumothorax in a non-smoker"],"prefix":"10.1136","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1683-9348","authenticated-orcid":false,"given":"Supriya","family":"Adiody","sequence":"first","affiliation":[{"name":"Respiratory Medicine, Jubilee Mission Medical College Hospital and Research Institute, Thrissur, Kerala, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-7468-4626","authenticated-orcid":false,"given":"Vishnu","family":"Narayanan S","sequence":"additional","affiliation":[{"name":"Respiratory Medicine, Jubilee Mission Medical College Hospital and Research Institute, Thrissur, Kerala, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Austin","family":"Raj","sequence":"additional","affiliation":[{"name":"Cardiothoracic and Vascular Surgery, Jubilee Mission Medical College Hospital and Research Institute, Thrissur, Kerala, India"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2026,6,10]]},"reference":[{"key":"2026061004051336000_19.6.e273149.1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ccm.2016.04.010"},{"key":"2026061004051336000_19.6.e273149.2","first-page":"1802044","article-title":"Prevalence of Birt-Hogg-Dub\u00e9 syndrome in patients with primary spontaneous pneumothorax","volume":"53","author":"Johannesma","year":"2019","journal-title":"Eur Respir J"},{"key":"2026061004051336000_19.6.e273149.3","first-page":"190135","article-title":"Characteristics of pulmonary cysts in Birt-Hogg-Dub\u00e9 syndrome","volume":"29","author":"Tobino","year":"2020","journal-title":"Eur Respir Rev"},{"key":"2026061004051336000_19.6.e273149.4","first-page":"205","article-title":"Molecular genetics and clinical features of Birt-Hogg-Dub\u00e9 syndrome","volume":"15","author":"Schmidt","year":"2018","journal-title":"Nat Rev Urol"},{"key":"2026061004051336000_19.6.e273149.5","first-page":"389","article-title":"Spontaneous pneumothoraces in Birt-Hogg-Dub\u00e9 syndrome","volume":"164","author":"Gupta","year":"2023","journal-title":"Chest"},{"key":"2026061004051336000_19.6.e273149.6","first-page":"1","article-title":"Risk of renal tumours in Birt-Hogg-Dub\u00e9 syndrome","volume":"112","author":"Zbar","year":"2020","journal-title":"J Natl Cancer Inst"}],"container-title":["BMJ Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bcr-2026-273149","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T11:05:22Z","timestamp":1781089522000},"score":1,"resource":{"primary":{"URL":"https:\/\/casereports.bmj.com\/lookup\/doi\/10.1136\/bcr-2026-273149"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6]]},"references-count":6,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2026,6,10]]},"published-print":{"date-parts":[[2026,6]]}},"alternative-id":["10.1136\/bcr-2026-273149"],"URL":"https:\/\/doi.org\/10.1136\/bcr-2026-273149","relation":{},"ISSN":["1757-790X"],"issn-type":[{"value":"1757-790X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6]]}}}