Radiosensitivity of fibroblasts from patients with retinoblastoma and chromosome-13 anomalies.

Diploid fibroblast cell strains derived from 14 patients with various forms of retinoblastoma (RB) and 5 non-RB patients with constitutional chromosome anomalies involving chromosome 13 were assayed for their clonogenic survival after X-irradiation. Cells from a patient with ataxia telangiectasia (AT) was used as a radiosensitive reference strain. When compared with cell strains from 7 healthy persons as normal controls, a marked radiosensitivity was observed in strain from an AT patient. However, none of the cell strains derived from RB patients or patients with inborn anomalies in chromosome 13 showed pronounced deviation from the normal range of radiosensitivity. The findings thus did not warrant either the RB as radiosensitive genetic disease or the presence of repair locus on chromosome 13, deletion or triplication of which was previously suggested to link to radiosensitivity.