ABSTRACT
Although a rare form of childhood cancer, retinoblastoma (RB) assumes a very important position in clinical oncology because of its high curability without significant loss of vision with modern treatment in early-stage disease, its
high lethality in late-stage disease, its autosomal dominant inheritance (with the lessons that it has taught the subject of genetic oncogenesis), and its tendency to affect both eyes.1,2 Whereas approximately one-third of all cases of RB are genetically determined and have multifocal or bilateral disease, only 10-20 per cent of affected children have a positive family history, implying a high new mutation rate. Survivors of genetically determined RB are at increased risk of developing second non-ocular cancers. Because of its familial tendency, the genetics of predisposition to RB and second tumours, genetic counselling and screening programmes have been the subject of much recent research.
