Characterization by FISH of a t(5;13) in a patient with bilateral retinoblastoma

We have used fluorescence in situ hybridization (FISH) with a biotinylated cosmid probe (13q14) to screen 25 unrelated cases with bilateral retinoblastoma and one case with unilateral retinoblastoma. In 25 cases no deletion or chromosome rearrangements were found. One constitutional mutation resulting from a de novo balanced chromosome translocation (5;13) in a patient with bilateral retinoblastoma was detected.