Epidemiology and clinical features of Birt-Hogg-Dube syndrome: A nationwide population-based study in South Korea

Background Birt-Hogg-Dube (BHD) syndrome is an ultrarare lung disease with unclear prevalence and incidence. Our study aimed to identify the epidemiological and clinical features of BHD syndrome by using nationwide claims data from the Korean Health Insurance Review and Assessment service. Methods Patients with BHD syndrome who had the following criteria were included: 1) tested for folliculin gene mutation, and 2) had at least one of the conditions: other specified malformation syndromes, fibrofolliculoma, acrochordon, lung cyst, cancer, and pneumothorax based on International Classification of Disease-10 code. Results We found 26 patients with BHD syndrome from 2017 to 2019. The prevalence of BHD syndrome was 5.67 per 10(7) population, with no peak age. Among incidence cases, the median age of diagnosis was 51 years, with slightly more females than males (n = 15, 57.7%). Over half of the patients (n =14, 53.8%) experienced pneumothorax, and 10 (38.5%) developed malignant neoplasm within the clinical course. Conclusions The prevalence of BHD syndrome in Korea is extremely low. However, affected patients manifest several comorbidities, including malignant neoplasm and repetitive pneumothorax.