AbstractA number of unique genetic features are observed in hepatoblastoma that have provided insights into the origins of hepatoblastoma. Hallmark cytogenetic changes in hepatoblastoma include the acquisition of additional copies of whole chromosomes and a recurring unbalanced translocation involving 1q. Genetic syndromes are associated with approximately 15% of hepatoblastoma and the understanding and recognition of these syndromes will be important in determining future surveillance studies needed to prevent additional cancers in survivors as well as in some case guide the care of family members. This article will review the genetic changes, both germ line and acquired, that are recurring events in hepatoblastoma, with emphasis on how these genetic changes could work together with other developmental factors and influence cancer predisposition, tumor growth, as well as aid in prognosis. Tumor‐specific signatures based on transcriptional or epigenetic alterations will be reviewed that might be used in the future to better diagnose and subtype the disease as well as predict prognosis and response to therapy. Pediatr Blood Cancer 2012; 59: 785–792. © 2012 Wiley Periodicals, Inc.