Departments of Toxicogenetics, Leiden University Medical Center, Leiden, The Netherlands.
Hum Mutat. 2010 Mar;31(3):247-53. doi: 10.1002/humu.21180.
The hereditary colon and endometrium cancer predisposition Lynch Syndrome (also called HNPCC) is caused by a germ-line mutation in one of the DNA mismatch repair (MMR) genes. A significant fraction of the gene alterations detected in suspected Lynch Syndrome patients is comprised of amino acid substitutions. The relevance for cancer risk of these variants is difficult to assess, as currently no time- and cost-effective, validated, and widely applicable functional assays for the measurement of MMR activity are available. Here we describe a rapid, cell-free, and easily quantifiable MMR activity assay for the diagnostic assessment of variants of the MLH1 MMR protein. This assay allows the parallel generation and functional analysis of a series of variants of the MLH1 protein in vitro using readily available, or preprepared, reagents. Using this assay we have tested 26 MLH1 variants and of these, 15 had lost activity. These results are in concordance with those obtained from first-generation assays and with in silico and pathology data. After its multifocal technical and clinical validation this assay could have great impact for the diagnosis and counseling of carriers of an MLH1 variant and their relatives.
遗传性结直肠和子宫内膜癌易感性 Lynch 综合征（也称为 HNPCC）是由 DNA 错配修复（MMR）基因之一的种系突变引起的。在疑似 Lynch 综合征患者中检测到的基因改变的一个显著部分由氨基酸取代组成。这些变异与癌症风险的相关性难以评估，因为目前尚无时间和成本效益高、经过验证且广泛适用的用于测量 MMR 活性的功能检测方法。在这里，我们描述了一种快速、无细胞且易于定量的 MLH1 MMR 蛋白变异体的 MMR 活性检测方法，用于 Lynch 综合征的诊断评估。该检测方法允许使用现成的或预先制备的试剂在体外平行生成和功能分析一系列 MLH1 蛋白的变体。使用该检测方法，我们已经测试了 26 种 MLH1 变体，其中 15 种变体失去了活性。这些结果与第一代检测方法以及计算机模拟和病理学数据的结果一致。在经过多方面的技术和临床验证后，该检测方法可能会对 MLH1 变体携带者及其亲属的诊断和咨询产生重大影响。
