Cost of exome analysis in patients with intellectual disability: a micro-costing study in a French setting.

Background: With the development of next generation sequencing technologies in France, exome sequencing (ES) has recently emerged as an opportunity to improve the diagnosis rate of patients presenting an intellectual disability (ID). To help French policy makers determine an adequate tariff for ES, we aimed to assess the unit cost per ES diagnostic test for ID from the preparation of the pre-analytical step until the report writing step and to identify its main cost drivers.

Methods: A micro-costing bottom-up approach was conducted for the year 2018 in a French setting as part of the DISSEQ study, a cost-effectiveness study funded by the Ministry of Health and performed in collaboration with the GAD (Génétique des Anomalies du Développement), a genetic team from the Dijon University Hospital, and a public sequencing platform, the Centre National de Recherche en Génomique Humaine (CNRGH).

Further clinical and molecular characterization of an XLID syndrome associated with BRWD3 variants, a gene implicated in the leukemia-related JAK-STAT pathway.

Background: Since the first description of a BRWD3-associated nonsydromic intellectual disability (ID) disorder in 2007, 21 additional families have been reported in the literature.

Methods: Using exome sequencing (ES) and international data sharing, we identified 14 additional unrelated individuals with pathogenic BRWD3 variants (12 males and 2 females, including one with skewed X-inactivation). We reviewed the 31 previously published cases in the literature with clinical data available, and describe the collective phenotypes of 43 males and 2 females, with 33 different BRWD3 variants.

mutations in the X-linked gene cause intellectual disability with pigmentary mosaicism and storage disorder-like features.

Introduction: Pigmentary mosaicism (PM) manifests by pigmentation anomalies along Blaschko's lines and represents a clue toward the molecular diagnosis of syndromic intellectual disability (ID). Together with new insights on the role for lysosomal signalling in embryonic stem cell differentiation, mutations in the X-linked transcription factor 3 () have recently been reported in five patients. Functional analysis suggested these mutations to result in ectopic nuclear gain of functions.

Second-tier trio exome sequencing after negative solo clinical exome sequencing: an efficient strategy to increase diagnostic yield and decipher molecular bases in undiagnosed developmental disorders.

Developmental disorders (DD), characterized by malformations/dysmorphism and/or intellectual disability, affecting around 3% of worldwide population, are mostly linked to genetic anomalies. Despite clinical exome sequencing (cES) centered on genes involved in human genetic disorders, the majority of patients affected by DD remain undiagnosed after solo-cES. Trio-based strategy is expected to facilitate variant selection thanks to rapid parental segregation.

Whole-exome sequencing identifies the first French MODY 6 family with a new mutation in the NEUROD1 gene.

Aim: The aim of the present study was to identify the affected gene in a French family with maturity-onset diabetes of the young (MODY) using whole-exome sequencing (WES).

Methods: WES was performed in one patient with MODY, and candidate variants were confirmed in members of the immediate family by Sanger sequencing.

Results: In the proband, a new heterozygous missense mutation (c.

A novel homozygous KCNQ3 loss-of-function variant causes non-syndromic intellectual disability and neonatal-onset pharmacodependent epilepsy.

Objective: Heterozygous variants in or, more rarely, genes are responsible for early-onset developmental/epileptic disorders characterized by heterogeneous clinical presentation and course, genetic transmission, and prognosis. While familial forms mostly include benign epilepsies with seizures starting in the neonatal or early-infantile period, de novo variants in or have been described in sporadic cases of early-onset encephalopathy (EOEE) with pharmacoresistant seizures, various age-related pathological EEG patterns, and moderate/severe developmental impairment. All pathogenic variants in or occur in heterozygosity.

Variant recurrence in neurodevelopmental disorders: the use of publicly available genomic data identifies clinically relevant pathogenic missense variants.

Purpose: Next-generation sequencing has revealed the major impact of de novo variants (DNVs) in developmental disorders (DD) such as intellectual disability, autism, and epilepsy. However, a substantial fraction of these predicted pathogenic DNVs remains challenging to distinguish from background DNVs, notably the missense variants acting via nonhaploinsufficient mechanisms on specific amino acid residues. We hypothesized that the detection of the same missense variation in at least two unrelated individuals presenting with a similar phenotype could be a powerful approach to reveal novel pathogenic variants.

Secondary actionable findings identified by exome sequencing: expected impact on the organisation of care from the study of 700 consecutive tests.

With exome/genome sequencing (ES/GS) integrated into the practice of medicine, there is some potential for reporting incidental/secondary findings (IFs/SFs). The issue of IFs/SFs has been studied extensively over the last 4 years. In order to evaluate their implications in care organisation, we retrospectively evaluated, in a cohort of 700 consecutive probands, the frequency and burden of introducing the search for variants in a maximum list of 244 medically actionable genes (genes that predispose carriers to a preventable or treatable disease in childhood/adulthood and genes for genetic counselling issues).

Lysosomal Signaling Licenses Embryonic Stem Cell Differentiation via Inactivation of Tfe3.

Self-renewal and differentiation of pluripotent murine embryonic stem cells (ESCs) is regulated by extrinsic signaling pathways. It is less clear whether cellular metabolism instructs developmental progression. In an unbiased genome-wide CRISPR/Cas9 screen, we identified components of a conserved amino-acid-sensing pathway as critical drivers of ESC differentiation.

De novo truncating variants in the intronless IRF2BPL are responsible for developmental epileptic encephalopathy.

Purpose: Developmental and epileptic encephalopathies (DEEs) are severe clinical conditions characterized by stagnation or decline of cognitive and behavioral abilities preceded, accompanied or followed by seizures. Because DEEs are clinically and genetically heterogeneous, next-generation sequencing, especially exome sequencing (ES), is becoming a first-tier strategy to identify the molecular etiologies of these disorders.

Methods: We combined ES analysis and international data sharing.

Recessive loss of function PIGN alleles, including an intragenic deletion with founder effect in La Réunion Island, in patients with Fryns syndrome.

Fryns syndrome (FS) is a multiple malformations syndrome with major features of congenital diaphragmatic hernia, pulmonary hypoplasia, craniofacial dysmorphic features, distal digit hypoplasia, and a range of other lower frequency malformations. FS is typically lethal in the fetal or neonatal period. Inheritance is presumed autosomal recessive.

Clinical whole-exome sequencing for the diagnosis of rare disorders with congenital anomalies and/or intellectual disability: substantial interest of prospective annual reanalysis.

PurposeCongenital anomalies and intellectual disability (CA/ID) are a major diagnostic challenge in medical genetics-50% of patients still have no molecular diagnosis after a long and stressful diagnostic "odyssey." Solo clinical whole-exome sequencing (WES) was applied in our genetics center to improve diagnosis in patients with CA/ID.MethodsThis retrospective study examined 416 consecutive tests performed over 3 years to demonstrate the effectiveness of periodically reanalyzing WES data.

Reducing diagnostic turnaround times of exome sequencing for families requiring timely diagnoses.

Background And Objective: 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.

Molecular diagnosis of PIK3CA-related overgrowth spectrum (PROS) in 162 patients and recommendations for genetic testing.

Purpose: Postzygotic activating mutations of PIK3CA cause a wide range of mosaic disorders collectively referred to as PIK3CA-related overgrowth spectrum (PROS). We describe the diagnostic yield and characteristics of PIK3CA sequencing in PROS.

Methods: We performed ultradeep next-generation sequencing (NGS) of PIK3CA in various tissues from 162 patients referred to our clinical laboratory and assessed diagnostic yield by phenotype and tissue tested.

Autosomal-Recessive Mutations in AP3B2, Adaptor-Related Protein Complex 3 Beta 2 Subunit, Cause an Early-Onset Epileptic Encephalopathy with Optic Atrophy.

Early-onset epileptic encephalopathy (EOEE) represents a heterogeneous group of severe disorders characterized by seizures, interictal epileptiform activity with a disorganized electroencephalography background, developmental regression or retardation, and onset before 1 year of age. Among a cohort of 57 individuals with epileptic encephalopathy, we ascertained two unrelated affected individuals with EOEE associated with developmental impairment and autosomal-recessive variants in AP3B2 by means of whole-exome sequencing. The targeted sequencing of AP3B2 in 86 unrelated individuals with EOEE led to the identification of an additional family.

Autosomal recessive variations of TBX6, from congenital scoliosis to spondylocostal dysostosis.

Proximal 16p11.2 microdeletions are recurrent microdeletions with an overall prevalence of 0.03%.