Dyskeratosis Congenita
A 52-year-old man presented to the pulmonary clinic with a 2-month history of cough and dyspnea on exertion. He had a history of pancytopenia, although previous evaluation, including bone marrow biopsy, had not resulted in any diagnosis of the cause. His brother had died after undergoing bone marrow transplantation for aplastic anemia. Physical examination revealed short stature, thin graying hair, missing teeth, nail dystrophy (Panel A), tongue leukoplakia (Panel B), and reticulated hypopigmentation of the neck (Panel C). Computed tomography of the chest revealed characteristic findings of pulmonary fibrosis that were predominant in the lower lobes. The triad of nail dystrophy, mucosal leukoplakia, and skin findings led to a clinical suspicion of dyskeratosis congenita. Dyskeratosis congenita is a heritable disorder of telomere maintenance that causes short telomeres, leading to manifestations such as bone marrow failure, cancer, and pulmonary fibrosis. Testing of peripheral-blood leukocytes confirmed that the telomere lengths in this patient were below the 1st percentile for age. The patient began taking danazol, a synthetic androgen that may lengthen telomeres, and had subsequent increases in his platelet, red-cell, and white-cell counts.