MOLECULAR DIAGNOSIS OF FAMILIAL ADENOMATOUS POLYPOSIS
MOLECULAR DIAGNOSIS OF FAMILIAL ADENOMATOUS POLYPOSIS
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DOI：
10.1056/nejm199312303292702
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发表时间：
1993-12-30
影响因子：
158.5
通讯作者：
KINZLER, KW
中科院分区：
文献类型：
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作者：
POWELL, SM;PETERSEN, GM;KINZLER, KW
背景。家族性腺瘤性息肉病是一种以多发结直肠肿瘤为特征的遗传性疾病。典型的诊断是基于对多发结直肠腺瘤的检测。最近在家族性腺瘤性息肉病患者中发现了APC基因的种系突变，这使得症状前分子诊断成为可能，但是在这个非常大的基因中，许多突变的广泛分布使得寻找这种突变变得不切实际。我们描述了一种新的方法，允许分子遗传学诊断大多数患者的疾病。我们筛选了来自约翰霍普金斯家族性腺瘤性息肉病登记处的62名无关患者的种系APC突变。初步筛选是通过分析体外合成的替代APC基因完成的。此外，通过等位基因特异性表达测定每个APC等位基因的相对转录量。蛋白分析显示62例患者中有51例（82%）的蛋白被截断。在其余11例患者中，有3例等位基因特异性表达试验显示APC基因的一个等位基因表达显著降低。这两种方法结合使用，成功地鉴定了62例患者中87%的种系APC突变。蛋白和等位基因特异性表达检测为家族性腺瘤性息肉病的分子诊断提供了一种实用、灵敏的方法。这种方法将促进护理，允许对有风险的受试者进行常规检测，并对自发突变进行遗传确认。
Background. Familial adenomatous polyposis is an inherited disease characterized by multiple colorectal tumors. The diagnosis has classically been based on the detection of multiple colorectal adenomas. The recent identification of germline mutations of the APC gene in patients with familial adenomatous polyposis makes presymptomatic molecular diagnosis possible, but the widespread distribution of the many mutations within this very large gene have heretofore made the search for such mutations impractical. We describe a novel approach that allows molecular genetic diagnosis in the majority of patients with the disease.Methods. We screened 62 unrelated patients from the Johns Hopkins Familial Adenomatous Polyposis Registry for germline APC mutations. Primary screening was accomplished by analysis of protein synthesized in vitro from surrogate APC genes. In addition, the relative amount of transcript from each APC allele was determined with an allele-specific-expression assay.Results. The protein assay revealed truncated protein in 51 of the 62 patients (82 percent). In 3 of the 11 remaining patients, the allele-specific-expression assay revealed significantly reduced expression of one allele of the APC gene. The use of these two assays in combination successfully identified germline APC mutations in 87 percent of the 62 patients.Conclusions. The protein and allele-specific-expression assays provide a practical and sensitive method for molecular diagnosis of familial adenomatous polyposis. This approach will facilitate care, allowing routine testing of subjects at risk and genetic confirmation of spontaneous mutations.