A syndrome characterized by predisposition for development of a broad spectrum of malignancies during childhood, including mainly brain, hematological and gastrointestinal cancers that has_material_basis_in homozygous or compound heterozygous mutation in the mismatch repair genes MLH1, MSH2, MSH6, or PMS2 on chromosomes 3p22.2, 2p21-p16, 2p16.3, and 7p22.1, respectively.