Inherited predisposition to pneumothorax: estimating the frequency of Birt-Hogg-Dubé syndrome from genomics and population cohorts.

Birt-Hogg-Dubé syndrome (BHDS) is the most common monogenic cause of pneumothorax. Most affected families have pathogenic variants in the FLCN gene. Using large genomic registries (UK Biobank (UKB), 100,000 Genomes Project and East London Genes & Health) including >550 000 individuals, we demonstrate that the frequency of clinically validated loss-of-function FLCN variants is 1 in 2710 to 4190. While the lifetime risk of pneumothorax in FLCN mutation carriers in the UKB and a BHDS clinical cohort was substantial (28.4% and 37.3%, respectively, to age 65 years), the lifetime risk of renal cancer was significantly lower in UKB than in BHDS patients (1% vs 32.1%). These findings highlight the importance of clinical context in managing individuals with FLCN mutations.