Two cases with chromosome 11 anomaly related to cancer are reported. The first one has a pericentric inversion (inv. p14 q12) with sympathoblastoma and Ondine's curse. The second one has a deletion (11p13) with aniridia and catalase deficiency but without Wilms tumor at two year of age. Retinoblastoma, nephroblastoma and sympathoblastoma may be related to genome modification. The mechanism of oncogenesis are discussed.