Phenotypically, RTEL1 mutations are known to be associated with a host of genetic diseases and disorders, including dyskeratosis congenita (DC) and its severe variant, Hoyeraal–Hreidarsson syndrome (HHs),3, 4, 5 bone marrow failure (BMF),3, 4, 5, 6, 7 very early‐onset monogenic inflammatory bowel disease (IBD) and IBD‐like colitis,5, 8, 9 pulmonary fibrosis,3, 4, 10, 11, 12, 13 liver disease4, 14 and myeloid neoplasms.7, 14, 15, 16. The gene discussed is RTEL1; the disease is dyskeratosis congenita.