Individuals with dyskeratosis congenita (DC) most commonly present with abnormal skin pigmentation, nail dystrophy, bone marrow failure and oral leukoplakia. Other features that may present include: epiphora, developmental delay, pulmonary disease, short stature, poor dentition, esophageal stricture, premature hair loss and an increased risk for a variety of malignancies. Individuals typically present during early childhood, often with abnormal skin pigmentation and nail dystrophy as the first clinical signs. By age 30, most individuals with DC have signs of bone marrow failure. However, there is a large degree of disease heterogeneity and severity, especially for heterozygous mutations in the TERT gene. Some patients may initially be characterized as having constitutional or idiopathic aplastic anemia or myelodysplastic syndromes. In addition, mutations in the TERC and TERT genes have been identified in individuals with reported idiopathic pulmonary fibrosis.10 Hoyeraal-Hreidarsson (HH) and Revesz Syndromes are severe forms of DC. HH is characterized by microcephaly, growth and mental retardation, spastic paresis, ataxia and immunodeficiency. Individuals with Revesz syndrome present with bilateral retinal exudative retinopathy and intracranial calcifications, in addition to many of the common DC features. Genetic anticipation can also be observed, with children displaying clinical features at an earlier age and/or with a more severe presentation as compared to a parent harboring the same mutation. In all forms of DC, telomere protection or maintenance is defective.