Germline splicing mutations of CDKN2A predispose to melanoma
Germline splicing mutations of CDKN2A predispose to melanoma
复制标题
DOI：
10.1038/sj.onc.1206736
复制
发表时间：
2003-09-25
期刊：
影响因子：
8
通讯作者：
Hogg, D
中科院分区：
文献类型：
--
作者：
Loo, JCY;Liu, L;Hogg, D
染色体9 p21上的CDKN 2A基因的编码突变与25-60%的家族性黑素瘤病例共分离，但仍有许多9 p21连锁的激酶缺乏CDKN 2A的种系编码突变。我们对167个黑色素瘤易感家族（至少两个受影响的一级亲属）的CDKN 2A外显子1 α、2、3和相邻内含子区域进行了测序，并检测到4个剪接位点变异，其中3个与疾病共分离。RT-PCR实验证实，这三个变体，包括一个AGgt到ATgt的突变，表现出创始人效应，影响剪接。虽然外显子1alpha剪接供体位点突变不完全消除剪接，但正确剪接的mRNA产生不能与CDK 4有效相互作用的蛋白质（Q50 P）。我们还进行了RT-PCR的mRNA从16个黑色素瘤倾向的激酶，以寻找隐藏的剪接位点深处的内含子，但没有发现剪接变异体。同时，我们使用等位基因特异性PCR对139个受影响的家庭进行了最近发现的IVS 2 - 105 A>G突变的筛查，但只发现了一个具有这种改变的家庭。我们的结论是，剪接位点突变确实易患疾病的一个子集的黑色素瘤倾向激酶。对CDKN 2A的其他剪接位点变异和其他非编码改变的表征，应该使我们能够在高危患者中检测到更广泛的突变。
Coding mutations of the CDKN2A gene on chromosome 9p21 cosegregate with 25-60% of familial melanoma cases, but there remains a number of 9p21-linked kindreds that lack germline coding mutations of CDKN2A. W e sequenced CDKN2A exons 1alpha, 2, 3, and the adjacent intronic regions in 167 melanoma-prone families ( at least two affected first-degree relatives), and detected four splice site variations, three of which cosegregate with the disease. RT-PCR experiments verified that these three variants, including an AGgt to ATgt mutation that demonstrates a founder effect, do affect splicing. While an exon 1alpha splice donor site mutation incompletely abolishes splicing, the correctly spliced mRNA yields a protein (Q50P) that cannot effectively interact with CDK4. We also performed RT-PCR on mRNA from 16 melanoma-prone kindreds to search for cryptic splice sites deep within introns, but identified no splice variants. Meanwhile, we screened 139 affected families using allele specific PCR for the recently discovered IVS2-105A >G mutation, but found only one family that possesses this alteration. We conclude that splice site mutations do predispose to disease in a subset of melanoma-prone kindreds. Characterization of additional splice site variants and other noncoding alterations of CDKN2A should allow us to detect a wider range of mutations in at-risk patients.