Genetic mosaicism at the insulin locus in liver associated with childhood hepatoblastoma

Hepatoblastoma is commonly associated with loss of heterozygosity (LOH) involving chromosome region IIp 15.5. This region may contain an as yet unidentified tumor suppressor gene relevant to this and other tumors associated with the Beckwith Wiedemann syndrome. Using the insulin (INS) locus as a marker for this region we have identified two of three patients with hepatoblastoma whose livers demonstrated genetic mosaicism. One tumor arose from the clone demonstrating LOH in the liver while the other arose from the clone without LOH. © 1995 Wiley‐Liss, Inc.