Hereditary thrombophilia: identification of nonsense and missense mutations in the protein C gene.
Hereditary thrombophilia: identification of nonsense and missense mutations in the protein C gene.
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遗传性血栓形成倾向：蛋白 C 基因中无义和错义突变的鉴定。
DOI：
10.1073/pnas.84.9.2829
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发表时间：
1987
影响因子：
11.1
通讯作者：
Riccardo Cortese
中科院分区：
文献类型：
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作者：
Giovanni Romeo;H. J. HASSANt;S. Staempfli;Laura Roncuzzi;Luciano CIANETTIt;Antonella Leonardio;Vicente Vicente;P. M. Mannucci;R. Bertina;Cesare PESCHLEt;Riccardo Cortese
分析了29名遗传性血栓形成倾向和蛋白C缺乏症的无关患者的蛋白C（一种抗凝丝氨酸蛋白酶）基因结构。通过与cDNA探针的Southern印迹杂交未证实基因缺失或总体重排。然而，两个不相关的患者表现出变异的限制性模式后Pvu II或BamHI消化，由于在最后一个外显子的突变：分析他们的家系，包括三个或七个杂合子，分别与酶和抗原水平降低约50%，显示异常的限制性模式在所有杂合子个体，但不是在正常的亲属。蛋白C基因的克隆和最后一个外显子的测序，使我们能够确定一个无义和错义突变，分别。在第一种情况下，密码子306（CGA，精氨酸）突变为框内终止密码子，从而产生新的Pvu II识别位点。在第二种情况下，BamHI回文序列中的错义突变（GGATCC-GCATCC）导致关键氨基酸的取代（在位置402处色氨酸至半胱氨酸的取代），其在真核丝氨酸蛋白酶中恒定保守。这些点突变可以解释两个家系中杂合子蛋白C缺乏的表型。
The structure of the gene for protein C, an anticoagulant serine protease, was analyzed in 29 unrelated patients with hereditary thrombophilia and protein C deficiency. Gene deletion(s) or gross rearrangement(s) was not demonstrable by Southern blot hybridization to cDNA probes. However, two unrelated patients showed a variant restriction pattern after Pvu II or BamHI digestion, due to mutations in the last exon: analysis of their pedigrees, including three or seven heterozygotes, respectively, with approximately 50% reduction of both enzymatic and antigen level, showed the abnormal restriction pattern in all heterozygous individuals, but not in normal relatives. Cloning of protein C gene and sequencing of the last exon allowed us to identify a nonsense and a missense mutation, respectively. In the first case, codon 306 (CGA, arginine) is mutated to an inframe stop codon, thus generating a new Pvu II recognition site. In the second case, a missense mutation in the BamHI palindrome (GGATCC----GCATCC) leads to substitution of a key amino acid (a tryptophan to cysteine substitution at position 402), invariantly conserved in eukaryotic serine proteases. These point mutations may explain the protein C-deficiency phenotype of heterozygotes in the two pedigrees.