Telomeres revisited: RTEL1 variants in pulmonary fibrosis.

For decades, it has been recognised that cases of pulmonary fibrosis cluster in families. While previous studies have implicated mutations in several surfactant-related proteins [1–3] and telomere-related genes [4–12], in most families the genetic basis of their disease has remained uncertain [13]. In this issue of the European Respiratory Journal, KANNENGIESSER et al. [14] report that rare genetic variants in regulator of telomere elongation helicase 1 (RTEL1) are associated with familial pulmonary fibrosis (FPF). Coupled with two other recent reports [7, 10], this work suggests that mutations in RTEL1 represent an important genetic cause of pulmonary fibrosis, responsible for disease in approximately 6% of families.