Frontiers in Biosciences (Elite Ed) Cytogenetics of hepatoblastoma

The cytogenetics of hepatoblastoma demonstrate recurring events which include whole chromosome trisomies, most commonly trisomy of chromosome 2, 8, or 10. In addition, unbalanced translocations involving a breakpoint on the proximal short arm of chromosome 1 are observed which results in a duplication of the long arm of chromosome 1q. The most commonly involved reciprocal chromosomal arm is 4q, although the reciprocal chromosome is highly variable and always results in a loss of chromosomal material. The full significance of these chromosomal changes has yet to be confirmed in large studies, however a suggestion of an association of duplication of regions of 2q with a poor prognosis. A rare subtype of hepatoblastoma, known as the small cell undifferentiated variant, is associated with deletion or translocation of 22q, the locus of the rhabdoid tumor gene, SMARCB1.