Its genetic etiology consists of germline variants in >30 distinct types of disorders, including Shwachman–Diamond syndrome (SDS), Fanconi anemia (FA), dyskeratosis congenita (DC), Diamond–Blackfan anemia (DBA), and recently identified alcohol dehydrogenase 5/aldehyde dehydrogenase 2 (ADH5/ALDH2) deficiency [3–6]. The gene discussed is ADH5; the disease is dyskeratosis congenita.