Are bilateral tumours hereditary?

Early observations regarding the age of onset, the family history and the clinical pattern of presentation of Wilms' tumour patients have been used to support the two-hit model of carcinogenesis, and to infer the hereditary nature of the bilateral form of the disease. Recent observations drawn from follow-up studies of offspring of unilaterally affected patients cast serious doubts upon the claim that a bilateral tumour implies the presence of an inherited predisposing mutation.