A decreasing tendency for cytogenetic abnormality in peripheral lymphocytes of retinoblastoma patients with 13q14 deletion mosaicism.

A significant decrease in the proportion of 13q14-deleted cells over a 9-month period was observed in a boy with retinoblastoma and 13q14 deletion mosaicism. To evaluate whether this phenomenon is generally the case, the bloods of three retinoblastoma patients with 13q14 deletion mosaicism reported in 1981 and 1982 were reexamined. A significant decrease in the proportion of abnormal cells was observed in three of four patients including the present case, suggesting that a 13q14 deletion mosaicism might disappear with age in some individuals.