Institute of Reproductive and Child Health, Ministry of Health Key Laboratory of Reproductive Health, Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Center, Beijing, China.
Departments of Molecular and Cellular Biology and Medicine, Baylor College of Medicine, Houston, TX 77030, USA.
Mol Genet Metab. 2018 May;124(1):94-100. doi: 10.1016/j.ymgme.2018.03.005. Epub 2018 Mar 18.
Neural tube defects (NTDs) are considered to be a complex genetic disorder, although the identity of the genetic factors remains largely unknown. Mouse model studies suggest a multifactorial oligogenic pattern of inheritance for NTDs, yet evidence from published human studies is surprisingly absent. In the present study, targeted next-generation sequencing was performed to screen for DNA variants in the entire coding regions and intron-exon boundaries of targeted genes using DNA samples from 510 NTD cases. These candidate genes were PCP genes, including VANGL1, VANGL2, CELSR1, SCRIB, DVL2, DVL3 and PTK7. Candidate variants were validated using Sanger sequencing. A total of 397 single nucleotide variants(SNVs) were identified with a mean depth of approximately 570×. Of these identified SNVs, 74 were predicted to affect protein function and had a minor allele frequency of <0.01 or unknown. Among these 74 missense SNVs, 10 were identified from six NTD cases that carried two mutated genes. Of the six NTD cases, three spina bifida cases and one anencephaly case carried digenic variants in the CELSR1 and SCRIB gene; one anencephaly case carried variants in the CELSR1 and DVL3 gene; and one spina bifida case carried variants in the PTK7 and SCRIB genes. Three cases that parental samples were available were confirmed to be compound heterozygous. None of the digenic variants were found in the 1000 genome database. The findings imply that genetic variation might interact in a digenic fashion to generate the visible NTD phenotypes and emphasize the importance of these genetic interactions in the development of NTDs in humans.
神经管缺陷（NTDs）被认为是一种复杂的遗传疾病，尽管其遗传因素的性质仍知之甚少。小鼠模型研究表明，NTDs 的遗传模式具有多因素的寡基因遗传特征，但发表的人类研究证据却出人意料地缺乏。在本研究中，使用来自 510 例 NTD 病例的 DNA 样本，通过靶向下一代测序对整个编码区和靶向基因的内含子-外显子边界的 DNA 变体进行了筛选。这些候选基因是 PCP 基因，包括 VANGL1、VANGL2、CELSR1、SCRIB、DVL2、DVL3 和 PTK7。使用 Sanger 测序对候选变体进行了验证。总共鉴定出 397 个单核苷酸变异（SNV），平均深度约为 570×。在这些鉴定出的 SNVs 中，有 74 个被预测会影响蛋白质功能，其次要等位基因频率<0.01 或未知。在这 74 个错义 SNVs 中，有 10 个是从携带两个突变基因的 6 个 NTD 病例中发现的。在这 6 个 NTD 病例中，3 例脊柱裂病例和 1 例无脑畸形病例携带 CELSR1 和 SCRIB 基因的双基因变异；1 例无脑畸形病例携带 CELSR1 和 DVL3 基因的变异；1 例脊柱裂病例携带 PTK7 和 SCRIB 基因的变异。有 3 个病例的父母样本可用，结果证实为复合杂合子。1000 基因组数据库中未发现双基因变异。这些发现表明遗传变异可能以双基因的方式相互作用，产生可见的 NTD 表型，并强调了这些遗传相互作用在人类 NTD 发生中的重要性。
