摘要
视网膜母细胞瘤(retinoblastoma,简称Rb),是一种婴幼儿时期易患的眼内恶性肿瘤,恶性程度高,易颅内转移而致死。该肿瘤可分为遗传及非遗传两种类型,约18%～40%病例的发病与遗传因素有关。近来的研究结果显示,视网膜母细胞瘤易感基因位于13号染色体长臂1区4带(13 q 14),遗传方式为常染色体显性遗传,外显率为90%。染色体13 q 14缺失危及了位于这一位点的Rb基因的一对等位基因,并使之失活,导致了肿瘤的发生。
In order to understand the relation between the Rb gene losser andchromosomal change in retinoblastoma, we examined a child with theunilateral and sporadic retinoblastoma both the peripheral lymphocyte Rbgene and peripheral lymphocyte chromosome. The result showed that theexamination of the chromosome could not find any visible abnormalchange when there were at least 10.0kb deletions at the Rb gene exa-mined with the method of molecular biology at DNA level. It demonstr-ated that the Rb gene losses within some degree can not be found withthe anysis of the chromosome. The chromosomal examination has ascarcity of high resolotion. It there is not chromosome 13q14 at thechromosomal level, the deletions of Rb gene are able to exist at themolecular level practically. So if you only depend on the result of thechromosomal examination to determine the existing condition of the Rbgene or make a hereditary consult, may be it is not correct sometimes.
