At a glance
ClinicalIndex Comparison RecordStandardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.
Etude Pilote Des différentes stratégies de séquençage Haut débit du génome Pour le Diagnostic génétique Des Patients Atteints de déficience Intellectuelle
In Brief
A clinical study evaluating Whole Genome Sequencing for Intellectual Disability. Completed, enrolled 3,825 participants across 14 sites.
Signals
Detailed Summary
Introduction : Intellectual Disability (ID) is the most common cause of referral in the pediatric genetic centers and is characterized by an extreme genetic heterogeneity corresponding to a myriad of rare diseases that complicates the identification of ID's. Overall today in France, for non-syndromic ID affected patients, the Fra-X detection, the chromosomal microarray analysis and Gene Panel Strategy of 44 ID selected genes leads to a global diagnostic yield for 1/3 patients leaving 2/3 of patients still with no diagnosis. The advent, and burst, of Next Generation Sequencing (NGS) technologies has clearly revolutionized the approaches to diagnosis and research in the field of rare diseases at an international. That's why the main hypothesis of DEFIDIAG is that Whole Genome Sequencing (WGS) could allow to improve the diagnostic performance and cost-effectiveness for French patients with ID. Objective : The main objective of this study is to compare ther percentage of genetic causal diagnosis identified in ID patients by performing trio WGS analysis vs the use of the current French reference strategy (ACPA, X-Fra, DI 44). Methods and design : This is a prospective study. The investigators expect to include 1275 index case with his/her 2 biological unaffected parents.
Study Details
Timeline
Arms & Interventions
Each included patient will be his own control; he will benefit from the two main strategies compared, in parallel. The diagnostic yield of Whole Genome Sequencing using a simplex strategy (WGSs) will be also investigated in parallel to the two main strategies but only in a randomized subgroup of the overall population coming for a first genetic advice. The results of the different strategies will be interpreted blindly, each participating laboratory being in charge for a given investigation center, either of 1) the trio or 2) the 44GPS (part of the reference strategy) and, for the randomized sub-population of the overall population coming for a first genetic advice, simplex analyses. Fra-X and chromosomal microarray analysis corresponding to the reference strategy will follow the routine circuit, which is mainly independent from the WGS circuit.
Interventions
The analysis will follow a consensus protocol that contains 3 obligatory steps: first of all, de novo variants (SNV, CNV and others SV) will be examined in the whole genome data set; then, a SNV/CNV/other SV analysis will be performed under a AR or X linked Mendelian mode hypothesis in the whole genomic regions of a OMIM extended list (that contains all genes already involved in human genetic diseases). Finally, analysis will focus on inherited pathogenic variants under an AD mode hypothesis (analysis of variations already reported as pathogenic in clinVar or HGMD pro; CNV or truncating variation in OMIM genes, etc). When these 3 steps analysis is completed then variants of interest identified at each step will be recorded until examination by a specific multidisciplinary meeting.