Abstract
Retinoblastoma, a tumor of the eye that occurs in approximately 1 in 20,000 live-born infants, has proved to be a valuable model for the study of the roles of single genes in the causation of cancer. In this issue of the Journal, Cavenee and colleagues show how recently introduced molecular genetic techniques can be used to predict which people at risk for retinoblastoma are likely to have the tumor.1 About 60 percent of cases of retinoblastoma are sporadic, but the remaining 40 percent are familial, with the predisposition to tumor development transmitted in an autosomal dominant manner. Not every . . .