[Telomere biology disorder]

Telomere biology disorders (TBD) are a heterogeneous group of rare inherited diseases caused by pathogenic variants in genes involved in telomere maintenance. They represent the leading monogenic cause of familial pulmonary fibrosis and inherited bone marrow failure in adults. Clinical manifestations are highly variable and may involve the lungs, bone marrow, liver and mucocutaneous tissues, together with immunological, renal, gastrointestinal and skeletal abnormalities. Diagnosis relies on recognizing this multisystem phenotype, genetic testing of telomere-related genes and, in selected cases, telomere length measurement. Identifying a TBD has important therapeutic implications, particularly in interstitial lung disease, where it influences the use of immunosuppressive therapies, antifibrotic treatment and organ transplantation strategies. It also enables appropriate genetic counselling and screening of at-risk relatives. This review summarizes current knowledge regarding the pathophysiology, diagnostic approach, clinical spectrum and multidisciplinary management of telomere biology disorders, with a particular focus on adult patients.