Clinical and genetic features of 334 Asian patients with Birt-Hogg-Dubé syndrome (BHDS) who presented with pulmonary cysts with or without a history of pneumothorax, with special reference to BHDS-associated pneumothorax

• Published in: PloS one 2023-07, Vol.18 (7), p.e0289175-e0289175
• Main Authors: Namba, Yukiko, Ebana, Hiroki, Okamoto, Shouichi, Kobayashi, Etsuko, Kurihara, Masatoshi, Sekimoto, Yasuhito, Tsuboshima, Kenji, Okura, Makiko Kunogi, Mitsuishi, Yoichiro, Takahashi, Kazuhisa, Seyama, Kuniaki
• Format: Article
• Language: English
• Subjects: Age; Biology and Life Sciences; Birt-Hogg-Dube syndrome; Cysts; Dermatology; Diagnosis; Exons; Females; Gastrointestinal cancer; Genetic aspects; Genetic testing; Genotypes; Kidney cancer; Males; Medical referrals; Medicine and Health Sciences; Patients; Phenotypes; Physical Sciences; Pneumothorax; Research and Analysis Methods; Risk factors; Skin cancer; Smoking; Tumors
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0289175

The clinical pulmonary manifestations and genetic features of Birt-Hogg-Dubé syndrome (BHDS) in Asian patients remained unclear. We aimed to clarify the clinical features of BHDS-associated pneumothorax (PTX) and retrospectively investigate potential contributing factors in the largest Asian cohort to date. We reviewed the clinical and genetic data collected in 2006-2017, from the BHDS patients who were Asian and presented with pulmonary cysts with or without a history of PTX. Data from 334 (41.3% males; 58.7% females) patients from 297 unrelated families were reviewed. Among them, 314 (94.0%) patients developed PTX. The median age at the first occurrence of PTX was 32 years, which was significantly lower in males (P = 0.003) and patients without notable skin manifestations (P < 0.001). Seventy-six (24.2%) patients experienced their first PTX episode before the age of 25 years. PTX simultaneously occurred in the bilateral lungs of 37 (11.8%) patients. Among 149 patients who had their first PTX episode at least 10 years before BHDS diagnosis, PTX occurred more frequently in males (P = 0.030) and light smokers than in nonsmokers (P = 0.014). The occurrence of PTX peaked in the early 30s and gradually decreased with age but remained high in females (P = 0.001). We identified 70 unique FLCN germline variants, including duplications (46.4%), substitutions (7.1%), insertions/deletions (30.0%), and variants affecting splicing (12.5%). Approximately 80% of Asian patients suspected of having BHDS could be genetically diagnosed by examining FLCN exons 7, 9, 11, 12, and 13. No apparent genotype-phenotype correlation regarding pulmonary manifestations was identified. Our findings indicate that sex, smoking history, and skin manifestations at BHDS diagnosis significantly influence the clinical features of BHDS-associated PTX. These findings may contribute to the appropriate management and treatment of BHDS-associated PTX.