Retinoblastoma, chromosome abnormalities and oncogene expression

Recurrent chromosomal abnormalities in retinoblastomas invlolve numbers 13, 1, and 6, as well as homogeneously staining regions (HSR) and double minutes (DMS). Evidence suggesting that chromosome 13 contains a gene responsible for tumorigenesis has already been presented. We postulate that the genetic changes resulting from abnormalities of chromosomes 1 and 6 and the HSR/DMS provide a selective growth advantage to cells in which they occur. Support for this hypothesis, as it relates to the HSR/DMS and oncogene amplification, is discussed.