Novel deep intronic mutation in the coagulation factor XIII a chain gene leading to unexpected RNA splicing in a patient with factor XIII deficiency
Novel deep intronic mutation in the coagulation factor XIII a chain gene leading to unexpected RNA splicing in a patient with factor XIII deficiency
复制标题
凝血因子 XIII 链基因中的新型深层内含子突变导致凝血因子 XIII 缺乏症患者出现意外的 RNA 剪接
DOI：
10.1186/s12881-019-0944-2
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发表时间：
2020-01-08
影响因子：
--
通讯作者：
Hu, Yu
中科院分区：
文献类型：
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作者：
Deng, Jun;Li, Dan;Hu, Yu
背景凝血因子XIII（FXIII）通过交联纤维蛋白在维持止血中起重要作用。缺乏FXIII会影响血凝块的稳定性，并增加严重出血的风险。先天性FXIII缺乏症是一种罕见的疾病。最近，我们确定了一个中国家庭与FXIII缺乏症，并调查先天性FXIII缺乏症的发病机制，贡献非编码致病variants.MethodsWe进行了常见的测试，编码测序有针对性的下一代测序（NGS），全基因组测序和拼接位点预测算法。结果先证者为F13 A1基因第799 - 12 G> A位突变纯合子。通过对小基因mRNA的直接测序，我们在突变型小基因mRNA中发现了10个碱基的内含子6插入片段。在体外抑制NMD可提高EGFP-F13 A1的相对表达量。结论我们报道了F13 A1基因第799 - 12 G> A位的突变，该突变产生了一个新的受体位点，并在翻译过程中产生了移码，引入了一个提前终止密码子。我们的结果支持提前终止密码子触发的NMD。在进行咨询和基因检测时，应注意潜在可变剪接位点的位置。TG升高提示在FXIII缺乏患者进行替代治疗时应注意血栓形成的风险。
BackgroundCoagulation factor XIII (FXIII) plays an essential role in maintaining hemostasis by crosslinking fibrin. Deficiency in FXIII affects clot stability and increases the risk of severe bleeding. Congenital FXIII deficiency is a rare disease. Recently, we identified a Chinese family with FXIII deficiency and investigated the pathogenesis of congenital FXIII deficiency, contributing non-coding pathogenic variants.MethodsWe performed common tests, coding sequencing by targeted next-generation sequencing (NGS), whole-genome sequencing and splice-sites prediction algorithms. The pathogenesis was investigated via minigene and nonsense-mediated mRNA decay (NMD) by experiments in vitro.ResultsThe proband is homozygote for a novel deep intronic c.799-12G > A mutation in theF13A1gene. Through direct sequencing of the minigenes mRNA, we found 10 bases of intron 6 insert in the mRNA of mutant minigenes mRNA. The relative expression of EGFP-F13A1 was higher by suppression of NMD in vitro. Furthermore, we found the proband with enhanced thrombin generation (TG).ConclusionWe reported a novel deep intronic c.799-12G > A mutation ofF13A1which produced a new acceptor site and frame shifting during translation introducing a premature termination codon. Our results support the premature termination codon triggered NMD. We need to pay attention to the position of potential alterable splicing sites while counselling and genetic test. The finding of enhanced TG indicated that we should be aware of the risk of thrombosis in patients with FXIII deficiency during replacement therapy.