先天性巨结肠RET基因突变的研究

Mutation of RET Oncogene in Hirschsprung's Disease

目的从分子水平探讨先天性巨结肠（ＨＤ）的发病机理，了解中国人群ＨＤ发病与酪氨酸激酶受体基因（ＲＥＴ基因）突变的关系。方法３０例ＨＤ患者（４例家族性和２６例散发性）和３０例对照者的外周静脉血经盐析法提取ＤＮＡ后，应用聚合酶链反应单链构象多态性（ＰＣＲＳＳＣＰ）分析方法，对ＲＥＴ基因第１５外显子（Ｅ１５）进行基因突变的检测，对阳性片段进行直接测序。结果２例家族性患者的Ｅ１５扩增片段在ＳＳＣＰ分析时发现有泳动变位。经ＤＮＡ自动测序证实１例为错义突变Ｌｙｓ８８９→Ｔｈｒ，另１例在Ｖ９０６和Ｓ９０９密码子分别存在两个同义突变（ＧＴＧＡＡＧＡＧＧＡＧＣＣＡ→ＧＴＴＡＡＧＡＧＧＡＧＴＣＡ）。结论ＲＥＴ基因突变与中国人群家族性ＨＤ的发生有密切关系。

Objective This study attempts to elucidate the relationship between RET oncogene and Chinese patients with Hirschsprung's disease.Methods Exon 15 of RET oncogene from 4 familial HD patients and 26 sporadic HD patients were analyzed with polymerase chain reaction single strand conformation polymorphism (PCR SSCP).The positive amplifying products were then sequenced.Results Two hete rozygous mutations were discovered in 2 familial HD patients. Direct DNA sequence analysis identified a missense mutation Lys 889→Thr in one patient and two silent mutations at codon V906 and S909 in the other (GTGAAGAGGAGCCA→GTTAAGAGGAGTCA).Conclusions These new discoveries indicate that RET mutations may play an important role in familial HD in the Chinese population.