作为孟德尔学说的显性遗传疾病的恶性肿瘤很少见,但可能有助于了解常见的“散发性”肿瘤的基本机制。Knudson的精原学说。特别指(虽然不是完全指)成视网膜细胞瘤而言,提出了为表达恶性表型至少要有两次独立的突变(“两次打击”)。在家族性癌的情况下,第一次突变是在生殖细胞系中遗传的,因此在每个细胞中已经存在。那么肿瘤的发生在适当组织的任何一个细胞中只需要再发生一次特定的突变。同一组织型的散发性肿瘤只在同 Malignant tumors that are dominant for Mendelian doctrine are rare, but may help to understand the basic mechanisms of common “sporadic” tumors. Knudson’s theory of refined origin. In particular, although not exclusively, retinoblastomas, it is proposed that there must be at least two independent mutations (“two hits”) to express a malignant phenotype. In the case of familial cancer, the first mutation was inherited in the germ line and therefore already exists in every cell. Then the occurrence of a tumor requires only one more specific mutation in any cell of the proper tissue. Sporadic tumors of the same tissue type are only in the same