RUNX1 and hereditary thrombocytopenia and hematological cancer predisposition syndrome associated with RUNX1: Familial platelet disorder with associated myeloid malignancies (FPDMM) is an autosomal dominant disease caused by heterozygous germline mutations in RUNX1. It is characterized by thrombocytopenia, platelet dysfunction, and a predisposition to hematological malignancies.