Somatic Mutations in TSC1 and TSC2 Cause Focal Cortical Dysplasia
Somatic Mutations in TSC1 and TSC2 Cause Focal Cortical Dysplasia
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DOI：
10.1016/j.ajhg.2017.01.030
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发表时间：
2017-03-02
影响因子：
9.8
通讯作者：
Lee, Jeong Ho
中科院分区：
文献类型：
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作者：
Lim, Jae Seok;Gopalappa, Ramu;Lee, Jeong Ho
局灶性皮质发育不良（FCD）是散发性难治性局灶性癫痫的主要原因，需要手术治疗。最近有报道称，MTOR的脑体细胞突变占FCDII型（FCDII）的15%-25%，其特征是皮层分层异常和神经元畸形。然而，缺乏MTOR突变的fcdii患者的遗传病因尚不清楚。在这里，我们对5个重要的mTOR通路基因——pik3ca、PIK3R2、AKT3、TSC1和tsc2进行了深度杂交捕获和扩增子测序（读取深度为100 x-20,012 x），方法是使用来自40名mTOR突变阴性的FCDII个体的成对脑和唾液样本。我们发现40个个体中有5个（12.5%）在TSC1中有脑体细胞突变（c.64C>T）。[2] [p]；[p])和TSC2 (c.4639G>A]。[Va11547I1e])，这些结果在两个不同的测序平台上是可重复的。所有确定的突变通过破坏TSC1TSC2复合物的形成或功能诱导mTOR通路的过度激活。此外，在子宫内，crispr - cas9介导的Tsc1或Tsc2基因组编辑诱导自发性行为癫痫发作，以及巨细胞神经元和皮质层发育异常。这些结果表明，TSC1和TSC2的脑体细胞突变导致FCD，并且在子宫内应用CRISPR-Cas9系统有助于生成脑体细胞突变的神经发育疾病模型。
Focal cortical dysplasia (FCD) is a major cause of the sporadic form of intractable focal epilepsies that require surgical treatment. It has recently been reported that brain somatic mutations in MTOR account for 15%-25% of FCD type II (FCDII), characterized by cortical dyslamination and dysmorphic neurons. However, the genetic etiologies of FCDII-affected individuals who lack the MTOR mutation remain unclear. Here, we performed deep hybrid capture and amplicon sequencing (read depth of 100 x-20,012 x) of five important mTOR pathway genes-PIK3CA, PIK3R2, AKT3, TSC1, and TSC2-by using paired brain and saliva samples from 40 FCDII individuals negative for MTOR mutations. We found that 5 of 40 individuals (12.5%) had brain somatic mutations in TSC1 (c.64C>T [p.Arg22Trp] and c.610C>T [p.Arg204Cys]) and TSC2 (c.4639G>A [p.Va11547I1e]), and these results were reproducible on two different sequencing platforms. All identified mutations induced hyperactivation of the mTOR pathway by disrupting the formation or function of the TSC1TSC2 complex. Furthermore, in utero CRISPR-Cas9-mediated genome editing of Tsc1 or Tsc2 induced the development of spontaneous behavioral seizures, as well as cytomegalic neurons and cortical dyslamination. These results show that brain somatic mutations in TSC1 and TSC2 cause FCD and that in utero application of the CRISPR-Cas9 system is useful for generating neurodevelopmental disease models of somatic mutations in the brain.