PDF(Pubmed)
Abstract：
Purpose: Patients with rare or ultra-rare genetic diseases, which affect 350 million people worldwide, may experience a diagnostic odyssey. High-throughput sequencing leads to an etiological diagnosis in up to 50% of individuals with heterogeneous neurodevelopmental or malformation disorders. There is a growing interest in additional omics technologies in translational research settings to examine the remaining unsolved cases. Methods: We gathered 30 individuals with malformation syndromes and/or severe neurodevelopmental disorders with negative trio exome sequencing and array comparative genomic hybridization results through a multicenter project. We applied short-read genome sequencing, total RNA sequencing, and DNA methylation analysis, in that order, as complementary translational research tools for a molecular diagnosis. Results: The cohort was mainly composed of pediatric individuals with a median age of 13.7 years (4 years and 6 months to 35 years and 1 month). Genome sequencing alone identified at least one variant with a high level of evidence of pathogenicity in 8/30 individuals (26.7%) and at least a candidate disease-causing variant in 7/30 other individuals (23.3%). RNA-seq data in 23 individuals allowed two additional individuals (8.7%) to be diagnosed, confirming the implication of two pathogenic variants (8.7%), and excluding one candidate variant (4.3%). Finally, DNA methylation analysis confirmed one diagnosis identified by genome sequencing (Kabuki syndrome) and identified an episignature compatible with a BAFopathy in a patient with a clinical diagnosis of Coffin-Siris with negative genome and RNA-seq results in blood. Conclusion: Overall, our integrated genome, transcriptome, and DNA methylation analysis solved 10/30 (33.3%) cases and identified a strong candidate gene in 4/30 (13.3%) of the patients with rare neurodevelopmental disorders and negative exome sequencing results.
摘要：
目的：罕见或超罕见遗传病患者，影响了全球3.5亿人，可能会经历一次诊断性的冒险。高通量测序导致多达50％的异质性神经发育或畸形障碍个体的病因诊断。在翻译研究环境中，对其他组学技术的兴趣越来越大，以检查其余未解决的病例。方法：我们通过多中心项目收集了30例畸形综合征和/或严重神经发育障碍患者，其三外显子组测序和阵列比较基因组杂交结果为阴性。我们应用了短阅读基因组测序，总RNA测序，和DNA甲基化分析，按照这个顺序,作为分子诊断的补充翻译研究工具。结果：该队列主要由中位年龄为13.7岁（4岁6个月至35岁1个月）的儿科个体组成。单独的基因组测序在8/30个体中鉴定出至少一种具有高水平致病性证据的变异(26.7%),在其他7/30个体中鉴定出至少一种候选致病变异(23.3%)。23名个体的RNA-seq数据允许另外两名个体(8.7%)被诊断出来，确认两种致病变异的含义（8.7％），并不包括一个候选变体(4.3%)。最后,DNA甲基化分析证实了通过基因组测序（Kabuki综合征）鉴定的一种诊断，并在临床诊断为Coffin-Siris的患者中鉴定了与BAFopathy相容的表观特征，血液中具有阴性基因组和RNA-seq结果。结论：总体而言，我们整合的基因组，转录组，DNA甲基化分析解决了10/30（33.3％）的病例，并在4/30（13.3％）的罕见神经发育障碍患者中确定了一个强候选基因，外显子组测序结果为阴性。
