Bourchany Aurélie, Thauvin-Robinet Christel, Lehalle Daphné, Bruel Ange-Line, Masurel-Paulet Alice, Jean Nolwenn, Nambot Sophie, Willems Marjorie, Lambert Laetitia, El Chehadeh-Djebbar Salima, Schaefer Elise, Jaquette Aurélia, St-Onge Judith, Poe Charlotte, Jouan Thibaud, Chevarin Martin, Callier Patrick, Mosca-Boidron Anne-Laure, Laurent Nicole, Lefebvre Mathilde, Huet Frédéric, Houcinat Nada, Moutton Sébastien, Philippe Christophe, Tran-Mau-Them Frédéric, Vitobello Antonio, Kuentz Paul, Duffourd Yannis, Rivière Jean-Baptiste, Thevenon Julien, Faivre Laurence
Département de Pédiatrie 1, Hôpital d'Enfants, CHU Dijon et Université de Bourgogne, Dijon, France; Equipe Génétique des Anomalies du Développement, INSERM UMR1231, Université de Bourgogne-Franche Comté, Dijon, France.
Equipe Génétique des Anomalies du Développement, INSERM UMR1231, Université de Bourgogne-Franche Comté, Dijon, France; Centre de Génétique et Centre de Référence Anomalies du Développement et Syndromes Malformatifs, FHU TRANSLAD, Hôpital d'Enfants, CHU Dijon et Université de Bourgogne, Dijon, France.
Eur J Med Genet. 2017 Nov;60(11):595-604. doi: 10.1016/j.ejmg.2017.08.011. Epub 2017 Aug 12.
Whole-exome sequencing (WES) has now entered medical practice with powerful applications in the diagnosis of rare Mendelian disorders. Although the usefulness and cost-effectiveness of WES have been widely demonstrated, it is essential to reduce the diagnostic turnaround time to make WES a first-line procedure. Since 2011, the automation of laboratory procedures and advances in sequencing chemistry have made it possible to carry out diagnostic whole genome sequencing from the blood sample to molecular diagnosis of suspected genetic disorders within 50 h. Taking advantage of these advances, the main objective of the study was to improve turnaround times for sequencing results.
WES was proposed to 29 patients with severe undiagnosed disorders with developmental abnormalities and faced with medical situations requiring rapid diagnosis. Each family gave consent. The extracted DNA was sequenced on a NextSeq500 (Illumina) instrument. Data were analyzed following standard procedures. Variants were interpreted using in-house software. Each rare variant affecting protein sequences with clinical relevance was tested for familial segregation.
The diagnostic rate was 45% (13/29), with a mean turnaround time of 40 days from reception of the specimen to delivery of results to the referring physician. Besides permitting genetic counseling, the rapid diagnosis for positive families led to two pre-natal diagnoses and two inclusions in clinical trials.
This pilot study demonstrated the feasibility of rapid diagnostic WES in our primary genetics center. It reduced the diagnostic odyssey and helped provide support to families.
全外显子组测序（WES）现已应用于医学实践，在罕见孟德尔疾病的诊断中具有强大的应用价值。尽管WES的实用性和成本效益已得到广泛证明，但缩短诊断周转时间以使WES成为一线诊断程序至关重要。自2011年以来，实验室程序的自动化和测序技术的进步使得在50小时内从血液样本进行诊断性全基因组测序并得出疑似遗传疾病的分子诊断结果成为可能。利用这些进展，本研究的主要目的是缩短测序结果的周转时间。
对29例患有严重未确诊发育异常疾病且面临需要快速诊断的医疗情况的患者进行WES检测。每个家庭均签署了知情同意书。提取的DNA在NextSeq500（Illumina）仪器上进行测序。数据按照标准程序进行分析。变异位点使用内部软件进行解读。对每个影响蛋白质序列且具有临床相关性的罕见变异进行家系分离检测。
诊断率为45%（13/29），从接收标本到向转诊医生提供结果的平均周转时间为40天。除了能够进行遗传咨询外，对检测结果呈阳性的家庭进行的快速诊断还促成了两例产前诊断以及两例患者纳入临床试验。
这项初步研究证明了在我们的初级遗传学中心进行快速诊断性WES的可行性。它减少了诊断过程中的漫长摸索，并有助于为家庭提供支持。
