中国人家族性腺瘤性患肉病患者结肠腺瘤性患肉病基因的胚系突变

目的 探讨中国人家族性腺瘤性息肉病(familial adenomatous polyposis,FAr)患者的结肠腺瘤性息肉病(adenomatous polyposis coli,APC)基因的胚系突变类型.方法 对9个FAP家系18名成员进行多重连接依赖性探针扩增(multiplex ligation-dependent probe amplification,MLPA)检测APC基因有无大片段缺失.再应用PCR扩增APC基因的15个外显子区域,经变性高效液相色谱(denaturing high performance liquid chromatography,DHPLC)对每个扩增片段进行筛查,流出峰异常的片段,经DNA测序验证小片段的改变.结果 9个家系中有3个家系发现有APC基因的胚系突变:家系2为c.3184-3187 del CAhA,家系4为c.5432C＞T,家系9为c.3925-3929 del AAAAG.3种突变中c.5432C＞T在数据库中未见报道.结论 中国人不同的APC基因的胚系突变可引起FAP;无APC胚系突变的FAP患者的发病可能存在其他的机制.

Germline mutation of adenomatous polyposis coli gene in Chinese patients with familial adenomatous polyposis

OBJECTIVE: To explore the characteristics of adenomatous polyposis coli (APC) gene germline mutations in Chinese patients with familial adenomatous polyposis (FAP). METHODS: Eighteen members from nine FAP pedigrees were studied by using multiplex ligation-dependent probe amplification(MLPA) to detect large fragment deletion of APC gene. Then, PCR were performed to amplify all exons of APC gene for mutation screening by denaturing high performance liquid chromatography (DHPLC). When abnormal elution profile of DHPLC was found, DNA sequencing was performed to determine the mutations. RESULTS: Mutations were identified in three pedigrees among the nine pedigrees. They were c.3184_3187 del CAAA in pedigree 2, c.5432C to T in pedigree 4 and c.3925_3929 del AAAAG in pedigree 9 respectively. Among them, c.5432C to T was novel. CONCLUSION: APC gene germline mutations can cause the development of FAP. The FAP patients without APC gene germline mutations could be caused by other mechanisms.