*Especially in children and young adults, MDS and AML may develop secondary to aplastic anemia, an inherited bone marrow failure syndrome or in the context of another underlying germline mutation which predisposes to the development of a myeloid neoplasm, of which GATA2 and SAMD9/SAMD9L are at the moment the most common. The gene discussed is SAMD9; the disease is myelodysplastic syndrome.