Loss-of-function variants in CUL3 cause a syndromic neurodevelopmental disorder

Purpose De novovariants inCUL3(Cullin-3 ubiquitin ligase) have been strongly associated with neurodevelopmental disorders (NDDs), but no large case series have been reported so far. Here we aimed to collect sporadic cases carrying rare variants inCUL3,describe the genotype-phenotype correlation, and investigate the underlying pathogenic mechanism.MethodsGenetic data and detailed clinical records were collected via multi-center collaboration. Dysmorphic facial features were analyzed using GestaltMatcher. Variant effects on CUL3 protein stability were assessed using patient-derived T-cells.ResultsWe assembled a cohort of 35 individuals with heterozygousCUL3variants presenting a syndromic NDD characterized by intellectual disability with or without autistic features. Of these, 33 have loss-of-function (LoF) and two have missense variants.CUL3LoF variants in patients may affect protein stability leading to perturbations in protein homeostasis, as evidenced by decreased ubiquitin-protein conjugatesin vitro. Specifically, we show that cyclin E1 (CCNE1) and 4E-BP1 (EIF4EBP1), two prominent substrates of CUL3, fail to be targeted for proteasomal degradation in patient-derived cells.ConclusionOur study further refines the clinical and mutational spectrum ofCUL3-associated NDDs, expands the spectrum of cullin RING E3 ligase-associated neuropsychiatric disorders, and suggests haploinsufficiency via LoF variants is the predominant pathogenic mechanism

Genetic landscape of a large cohort of Primary Ovarian Insufficiency : New genes and pathways and implications for personalized medicine

Background Primary Ovarian Insufficiency (POI), a public health problem, affects 1-3.7% of women under 40 yield-ing infertility and a shorter lifespan. Most causes are unknown. Recently, genetic causes were identified, mostly in single families. We studied an unprecedented large cohort of POI to unravel its molecular pathophysiology.Methods 375 patients with 70 families were studied using targeted (88 genes) or whole exome sequencing with pathogenic/likely-pathogenic variant selection. Mitomycin-induced chromosome breakages were studied in patients' lymphocytes if necessary. Findings A high-yield of 29.3% supports a clinical genetic diagnosis of POI. In addition, we found strong evidence of pathogenicity for nine genes not previously related to a Mendelian phenotype or POI: ELAVL2, NLRP11, CENPE, SPATA33, CCDC150, CCDC185, including DNA repair genes: C17orf53(HROB), HELQ, SWI5 yielding high chromo-somal fragility. We confirmed the causal role of BRCA2, FANCM, BNC1, ERCC6, MSH4, BMPR1A, BMPR1B, BMPR2, ESR2, CAV1, SPIDR, RCBTB1 and ATG7 previously reported in isolated patients/families. In 8.5% of cases, POI is the only symptom of a multi-organ genetic disease. New pathways were identified: NF-kB, post-translational regulation, and mitophagy (mitochondrial autophagy), providing future therapeutic targets. Three new genes have been shown to affect the age of natural menopause supporting a genetic link.Interpretation We have developed high-performance genetic diagnostic of POI, dissecting the molecular pathogene-sis of POI and enabling personalized medicine to i) prevent/cure comorbidities for tumour/cancer susceptibility genes that could affect life-expectancy (37.4% of cases), or for genetically-revealed syndromic POI (8.5% of cases), ii) predict residual ovarian reserve (60.5% of cases). Genetic diagnosis could help to identify patients who may benefit from the promising in vitro activation-IVA technique in the near future, greatly improving its success in treating infertility.Funding Universite? Paris Saclay, Agence Nationale de Biome?decine.Copyright (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)Peer reviewe

A Solve-RD ClinVar-based reanalysis of 1522 index cases from ERN-ITHACA reveals common pitfalls and misinterpretations in exome sequencing

Purpose Within the Solve-RD project (https://solve-rd.eu/), the European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies aimed to investigate whether a reanalysis of exomes from unsolved cases based on ClinVar annotations could establish additional diagnoses. We present the results of the “ClinVar low-hanging fruit” reanalysis, reasons for the failure of previous analyses, and lessons learned. Methods Data from the first 3576 exomes (1522 probands and 2054 relatives) collected from European Reference Network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies was reanalyzed by the Solve-RD consortium by evaluating for the presence of single-nucleotide variant, and small insertions and deletions already reported as (likely) pathogenic in ClinVar. Variants were filtered according to frequency, genotype, and mode of inheritance and reinterpreted. Results We identified causal variants in 59 cases (3.9%), 50 of them also raised by other approaches and 9 leading to new diagnoses, highlighting interpretation challenges: variants in genes not known to be involved in human disease at the time of the first analysis, misleading genotypes, or variants undetected by local pipelines (variants in off-target regions, low quality filters, low allelic balance, or high frequency). Conclusion The “ClinVar low-hanging fruit” analysis represents an effective, fast, and easy approach to recover causal variants from exome sequencing data, herewith contributing to the reduction of the diagnostic deadlock

Coupling DGT passive samplers and multi-collector ICP-MS: a new tool to measure Pb and Zn isotopes composition in dilute aqueous solutions

International audienceUsing zinc (Zn) and lead (Pb) isotopes is a powerful tool to track metal pollution in environment. In this study we have developed the coupling between DGT passive samplers and multi-collector ICP-MS to measure Pb and Zn isotopic ratios in dilute aqueous solutions. The benefits of this coupling are multiple: the use of DGT device allows achieving an isotopic composition of natural water integrated over time and to pre-concentrate metals in situ. This development will greatly facilitate the field collection of samples and their preparations in cleanroom prior to their isotopic analyses. To test the capability of DGT samplers a series of experiments was achieved in cleanroom and in experimental pilot simulating a water flow. These tests have shown that there is no fractionation of Pb isotopes due to the use of DGT within the reported precision of MC-ICPMS measurements. For Zn, the diffusion process through a membrane, inherent to the use of DGT device, induces a fractionation between the isotopic composition obtained by the DGT and the natural composition. However, this bias can be easily corrected by using a simple relation independent of the time of exposure and the thickness of diffusion layer. The coupling DGT passive samplers and multi-collector ICP-MS is suitable to determine the Pb and Zn isotopic compositions in natural waters and offers new perspectives to track the anthropic pollutions in the hydrosphere

Analysis of Enzyme Activity and Cellular Function for the N80S and S480F Asparagine Synthetase Variants Expressed in a Child with Asparagine Synthetase Deficiency

Asparagine Synthetase Deficiency (ASNSD) is a disease caused by mutations in asparagine synthetase (ASNS). Newborns exhibit microcephaly, intractable epileptic-like seizures, progressive brain atrophy, and axial hypotonia. ASNSD results in global developmental delays and premature death. The present report describes a 9-year-old child who is a compound heterozygote with ASNS mutations c.1439C > T and c.239A > G leading to variants p.S480F and p.N80S, respectively. When grown in a complete culture medium, primary fibroblasts from the child contained ASNS mRNA and protein levels similar to an unrelated wild-type fibroblast cell line. When the child’s fibroblasts were cultured for up to 72 h in a medium lacking asparagine, proliferation was reduced by about 50%. Purification of ASNS proteins harboring either the S480F or the N80S substitution had reduced enzymatic activity by 80% and 50%, respectively. Ectopic expression of either variant in ASNS-null Jensen rat sarcoma (JRS) cells did not support proliferation in the absence of medium-supplied asparagine, whereas expression of wild-type enzyme completely restored growth. These studies add to the list of pathogenic ASNS variants and use enzyme activity and protein expression in ASNS-null cells to expand our knowledge of the biological impact of mutations in the ASNS gene

Pontocerebellar Hypoplasia Type 1D: A Case Report and Comprehensive Literature Review

Pontocerebellar hypoplasia (PCH) is an autosomal recessive, neurodegenerative disorder with multiple subtypes leading to severe neurodevelopmental disabilities. PCH type 1 D is linked to alterations in the EXOSC9 gene. EXOSC9 is a component of the RNA exosome, an evolutionarily conserved ribonuclease complex essential for RNA degradation and processing. The clinical phenotype is characterized by cerebellar and pontine hypoplasia associated with motor neuronopathy. To date, nine patients have been reported in the literature with PCH1D. We report the case of an infant with PCH type 1D due to two variants in the EXOCS9 gene (NM_001034194.1: c.41T>C-p.Leu14Pro) and a novel variant (c.643C>T-p.Arg212*). This report thoroughly reviews the literature PCH1D and highlights the crucial role of the exosome in cellular homeostasis

Origin of French 14th to 16th century Alabaster Artwork from Ile-de-France assessed through multi-isotope Archaeometry (S, O, Sr)

The trade roads of Medieval and Renaissance gypsum and anhydrite alabaster (CaSO4.2H2O and CaSO4) have so far been investigated mainly by art historians based on iconographic or stylistic comparisons. Unlikely to marble artwork, only few studies have so far addressed the mineralogical, geochemical and isotopic fingerprints of raw alabaster compared to those of alabaster sculptures [1-3]. A pilot study of isotope fingerprinting on French alabaster sculptures [4] has shown that sulphur and oxygen isotopes of gypsum can be used in combination with 87Sr/86Sr ratios to trace alabaster artwork back to the historical quarries from which the raw material was extracted. Samples of medieval and renaissance sculpture fragments of different provenance (Burgundy, Lorraine, Languedoc, Pyrenees) could be successfully and unambiguously linked to the ancient gypsum quarries from France (Jura, Alps, Provence, Burgundy, Lorraine), Spain (Aragon and Catalonia), England (Nottingham). Indeed the isotopic signatures of the different historical exploitations show high intra-group homogeneity and strong inter-group contrasts, main condition for forensic work on artwork provenance. Furthermore, the chosen analytical techniques (continuous flow IRMS, TIMS) permit the use of microsamples in the low mg range ensuring that damage to sculptures is minimal. The Louvre Museum currently undertakes an art-historical study on the provenance of its alabaster artwork of the Ile de France region and more generally of the North of France from the 14th to the 16th century and has included isotope characterization as a means to better constrain the hypotheses on alabaster trade during this period. The Louvre samples are completed by related alabaster artwork provided by the Cleveland Museum of Art and from the towns of Calais and Cluny. The data base of French historical raw alabaster is further extended, notably for the Burgundy region. Here we present first results on S, O and Sr isotope fingerprints of the Ile-de-France statuary and its relations with French, Spanish and English alabaster exploitations

Methylmalonyl-CoA Epimerase Deficiency Mimicking Propionic Aciduria

International audienc

Anthropometric data and parent’s level at 2 years of age.

<p>SD: Standard deviation</p><p>Anthropometric data and parent’s level at 2 years of age.</p