This includes genes mutated in rare hematological syndromes (ADA, GP6, IL17RA, PRF1, and SEC23B), reported in prior MDS/AML or inherited bone marrow failure (IBMF) series (DNAH9, SH2B3, and NAPRT1), or novel loci where loss-of- function of the identified germline variants was demonstrated (DHX34). The gene discussed is NAPRT; the disease is Bone marrow hypocellularity.