Ranzani G N, Salerno-Mele P, Maltoni M, Talarico D, Della Valle G, Amadori D
Dipartimento di Genetica e Microbiologia A. Buzzati-Traverso, Università di Pavia, Italy.
Mol Biol Med. 1988 Dec;5(3):145-53.
The c-Ha-ras-1 proto-oncogene locus is characterized by a restriction fragment length polymorphism resulting from length variation in a variable tandem repetition (VTR) region downstream from the structural part of the gene. The presence of uncommon alleles at this region has been suggested to be an informative marker for the development of different malignancies, including solid tumours. In order to identify possible genetic markers of cancer risk, we studied the c-Ha-ras-1 locus polymorphism in an Italian population characterized by a high incidence of stomach tumours. Gastric cancer patients, some having first-degree relatives affected by the same malignancy, and control subjects were studied. A total of 176 DNAs was analysed by the Southern blotting technique with TaqI restriction enzyme. This yields a fragment containing the sequence of variable length (VTR) and also allows detection of a cleavage site polymorphism. Thirteen different alleles were detected and some new common and rare variants were found. Our results do not provide evidence that the inheritance of any allele may predispose to gastric malignancies. Segregation analysis carried out on 13 patients' families demonstrated, without exception, a Mendelian inheritance of patterns.
c-Ha-ras-1原癌基因位点的特征是存在一种限制性片段长度多态性，这是由该基因结构部分下游可变串联重复（VTR）区域的长度变化所导致的。该区域存在罕见等位基因被认为是包括实体瘤在内的不同恶性肿瘤发生的一个信息性标志物。为了确定癌症风险的可能遗传标志物，我们在一个胃癌发病率高的意大利人群中研究了c-Ha-ras-1位点多态性。对胃癌患者（其中一些患者有患相同恶性肿瘤的一级亲属）和对照受试者进行了研究。用TaqI限制性内切酶通过Southern印迹技术分析了总共176份DNA。这产生了一个包含可变长度序列（VTR）的片段，并且还能检测到一个切割位点多态性。检测到了13种不同的等位基因，并发现了一些新的常见和罕见变体。我们的结果没有提供证据表明任何等位基因的遗传可能易患胃恶性肿瘤。对13个患者家庭进行的分离分析毫无例外都显示出孟德尔遗传模式。
