Telomere-Related Gene mutations in a Greek cohort of suspected monogenic pulmonary fibrosis patients

Background: Telomere-related genes (TRG) mutations are detected in 30% of familial pulmonary fibrosis (FPF) and are also associated with personal/familial extra-pulmonary disease suggestive of short telomere syndrome (STS). Aim: to evaluate the prevalence of TRG mutations in a national cohort of interstitial lung disease (ILD) with suspected genetic predisposition in Greece and to define patients’ characteristics and impact on outcome.Methods: Genetic diagnoses made between December 2014-September 2019 in patients with FPF, pulmonary fibrosis at young age or personal and/or family extra-pulmonary disease suggestive of STS were analyzed. Results: 150 ILD patients, 73% male, age-at-diagnosis 67 years old, 33% non-smokers, 75% with definite/probable UIP or CPFE, 93% with dyspnea/cough, FVC% pred 75%, DLCO% pred 49% were tested; FPF was 65%, 19% young age, 21% personal and 17% family extra-pulmonary disease suggestive of STS; 21% were tested for more than 1 indication. TRG pathogenic variations were detected in 19 (13%): 13 in a familial, 3 in young age and 3 in extra-pulmonary disease suggestive of STS context as follows: TERT, TERC, RTEL1, PARN, NOP10, NHP2 in 8,5,2,2,1 and 1 respectively. No difference was detected in epidemiological-clinical-radiologic-functional characteristics between patients without and with mutations apart from age-at-diagnosis [69 vs 62 years, p