人类每种癌都可在正常个体和遗传易感个体发生,最典型的呈高外显率的孟德尔式遗传。突变基因的携带者就是癌的一种高风险形式。所有的癌至少有一个种系突变,这种突变在杂合子携带者中增加了癌发生的风险。视网膜母细胞瘤(Rb)约40%的病例是由于种系突变,60%是非遗传型的。双侧受累者似乎均是种系病例,单侧的仅10～ Every human cancer can occur in normal individuals and genetically susceptible individuals, the most typical of which is Mendelian inheritance with high penetrance. Carriers of mutated genes are a high-risk form of cancer. All cancers have at least one germline mutation that increases the risk of carcinogenesis in heterozygous carriers. About 40% of retinoblastomas (Rb) are due to germline mutations and 60% are non-genetic. It seems that all patients with bilateral involvement are germline cases.