视网膜母细胞瘤是婴儿和幼儿的一种眼内恶性肿瘤。有三分之一患此肿瘤的病例是常染色体显性遗传。由于患视网膜母细胞瘤的若干患者,其所有体细胞的13号染色体长臂鈌失,故有人假设促成视网膜母细胞瘤的突变基因位于13号染色体的长臂中间。上述假设可以由下述观察来验证:家族性视网膜母细胞瘤突变基因是否与标记13号染色体一起分离。作者报道一个家系,其视网膜母细胞瘤突变基因和标记13号染色体是一起分 Retinoblastoma is an intraocular malignancy of infants and young children. One in three cases of this tumor is autosomal dominant. Since several patients with retinoblastoma have a long arm of all the somatic chromosomes 13 missing, one has hypothesized that the mutant gene that contributes to retinoblastoma is located in the middle of the long arm of chromosome 13. The above hypothesis can be verified by the observation that whether the familial retinoblastoma mutant gene is isolated with the marker chromosome 13 or not. The authors report a pedigree whose retinoblastoma mutant gene and marker chromosome 13 are grouped together