Lee Yong-Wha
Department of Laboratory Medicine and Genetics, Soonchunhyang University Bucheon Hospital and Soonchunhyang University College of Medicine, Bucheon, Gyeonggi 420-767, Republic of Korea.
Exp Ther Med. 2013 Dec;6(6):1550-1552. doi: 10.3892/etm.2013.1332. Epub 2013 Oct 8.
The point mutation is the most common genetic event in papillary thyroid carcinoma (PTC), occurring in 29-69% of such tumors. The V600E mutation accounts for up to 95% of all mutations. Therefore, the majority of diagnostic assays have been developed to detect only the V600E mutation of the gene. A peptide nucleic-acid (PNA)-clamp quantitative polymerase chain reaction (qPCR) was developed to detect the V600E mutation and other mutations in the gene. In this study, a 3-bp deletion mutation (c.1799_ 1801delTGA) was detected in a subject with a PTC by PNA clamp qPCR, in contrast with the results of allele-specific (AS)-PCR. The mutant allele was not detected by AS-PCR, but was detected using PNA-clamp PCR. The atypical 3-bp deletion mutation (c.1799_1801delTGA) was identified by confirmatory PCR combined with sequencing. The conversion of codons 600 (GTG) and 601 (AAA) into a single codon (GAA) resulted in the insertion of a glutamic acid residue into the activation segment of the B-raf protein (p.V600_K601delinsE). In cases where PTC is highly suspected but no mutation is detected by AS-PCR specific for V600E, PNA clamp qPCR, which is complementary to other sequencing methods, should be performed in order to detect other mutations in the gene.
点突变是甲状腺乳头状癌（PTC）中最常见的基因事件，在29%-69%的此类肿瘤中发生。V600E突变占所有突变的95%。因此，大多数诊断检测方法仅用于检测该基因的V600E突变。开发了一种肽核酸（PNA）夹定量聚合酶链反应（qPCR）来检测该基因的V600E突变和其他突变。在本研究中，通过PNA夹qPCR在一名PTC患者中检测到一个3碱基缺失突变（c.1799_1801delTGA），这与等位基因特异性（AS）-PCR的结果相反。AS-PCR未检测到突变等位基因，但使用PNA夹PCR检测到了。通过验证性PCR结合测序鉴定出非典型的3碱基缺失突变（c.1799_1801delTGA）。密码子600（GTG）和601（AAA）转换为单个密码子（GAA）导致在B-raf蛋白的激活片段中插入了一个谷氨酸残基（p.V600_K601delinsE）。在高度怀疑为PTC但V600E特异性AS-PCR未检测到突变的情况下，应进行与其他测序方法互补的PNA夹qPCR，以检测该基因的其他突变。
