Shan X, Yan M, Huang Y, Mao Y, Wang S, Zhao S
Department of Biology, Nanjing Railway Medical College.
Yi Chuan Xue Bao. 1990;17(2):154-60.
By using recombinant plasmid PHS-49 as a probe, BamHI restriction fragment length polymorphisms (RFLPs) was studied in tumour DNAs of 36 gastric carcinoma patients and normal tissue DNAs of 25 unaffected Chinese individuals. Ten alleles and eighteen genotypes for Ha-ras gene were found. Four "rare" restriction fragments of size less than 6 kilobase pairs (kb) are first reported for Ha-ras locus in present paper, we inferred that these alleles might be one of the characteristics of genetic polymorphisms in Chinese population. Moreover, the frequency of some "rare" alleles and genotypes occurred in gastric carcinoma samples is significantly higher than that occurred in normal individuals. The results of pedigree analysis for two patients showed that some heterozygotes carried three or four alleles. It suggested that there may be more than one copy of Ha-ras gene sequence existed in a chromosome. The possible causes of the phenomenon mentioned above were discussed.
以重组质粒PHS - 49为探针，研究了36例胃癌患者肿瘤DNA和25例未患癌中国个体正常组织DNA中的BamHI限制性片段长度多态性（RFLPs）。发现了Ha - ras基因的10个等位基因和18种基因型。本文首次报道了Ha - ras基因座的4个大小小于6千碱基对（kb）的“罕见”限制性片段，推测这些等位基因可能是中国人群遗传多态性的特征之一。此外，一些“罕见”等位基因和基因型在胃癌样本中的出现频率显著高于正常个体。对两名患者的家系分析结果表明，一些杂合子携带3个或4个等位基因。这表明一条染色体上可能存在不止一个拷贝的Ha - ras基因序列。并对上述现象的可能原因进行了讨论。
