Cryptic Telomere Dysfunction Diagnosed After Recurrent Opportunistic Pneumonia: A Case Report and Review

Telomere biology disorders (TBDs) represent a spectrum of inherited syndromes caused by defects in telomere maintenance, leading to progressive cellular senescence and multisystem involvement. Their clinical manifestations are often heterogeneous and may remain unrecognized until advanced complications arise. We describe a case of previously undiagnosed telomere dysfunction presenting with recurrent opportunistic pneumonia in an adult patient without an established history of immunodeficiency. The patient experienced multiple episodes of severe lower respiratory tract infections, including Pneumocystis jirovecii pneumonia, in association with cytopenias and subtle extrapulmonary findings. Initial diagnostic evaluations, including immunological and infectious workups, were inconclusive. Subsequent assessment of telomere length and genetic analysis revealed markedly shortened telomeres, confirming an underlying telomere biology disorder. The patient was managed with antimicrobial therapy, prophylaxis against opportunistic infections, and close multidisciplinary follow-up, with consideration for advanced therapeutic options. This case underscores the importance of maintaining a high index of suspicion for TBDs in patients with unexplained recurrent infections and hematologic abnormalities. Early diagnosis is critical to guide management, enable genetic counseling, and mitigate disease progression. This report also reviews the current literature on pulmonary complications, diagnostic challenges, and evolving management strategies in telomere biology disorders.