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.

• MeSH
• alely MeSH
• genotyp MeSH
• lidé MeSH
• mentální retardace * diagnóza   genetika   MeSH
• sekvenování exomu MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Nuclear deubiquitinase BAP1 (BRCA1-associated protein 1) is a core component of multiprotein complexes that promote transcription by reversing the ubiquitination of histone 2A (H2A). BAP1 is a tumor suppressor whose germline loss-of-function variants predispose to cancer. To our knowledge, there are very rare examples of different germline variants in the same gene causing either a neurodevelopmental disorder (NDD) or a tumor predisposition syndrome. Here, we report a series of 11 de novo germline heterozygous missense BAP1 variants associated with a rare syndromic NDD. Functional analysis showed that most of the variants cannot rescue the consequences of BAP1 inactivation, suggesting a loss-of-function mechanism. In T cells isolated from two affected children, H2A deubiquitination was impaired. In matching peripheral blood mononuclear cells, histone H3 K27 acetylation ChIP-seq indicated that these BAP1 variants induced genome-wide chromatin state alterations, with enrichment for regulatory regions surrounding genes of the ubiquitin-proteasome system (UPS). Altogether, these results define a clinical syndrome caused by rare germline missense BAP1 variants that alter chromatin remodeling through abnormal histone ubiquitination and lead to transcriptional dysregulation of developmental genes.

• MeSH
• chromatin chemie   imunologie   MeSH
• dítě MeSH
• faktor C1 hostitelské buňky genetika   imunologie   MeSH
• heterozygot MeSH
• histony genetika   imunologie   MeSH
• kojenec MeSH
• lidé MeSH
• missense mutace * MeSH
• mladiství MeSH
• mutace ztráty funkce * MeSH
• nádorové supresorové proteiny nedostatek   genetika   imunologie   MeSH
• neurovývojové poruchy genetika   imunologie   patologie   MeSH
• předškolní dítě MeSH
• proteasomový endopeptidasový komplex genetika   imunologie   MeSH
• protein BRCA1 genetika   imunologie   MeSH
• regulace genové exprese MeSH
• restrukturace chromatinu genetika   imunologie   MeSH
• rodina MeSH
• T-lymfocyty imunologie   patologie   MeSH
• thiolesterasa ubikvitinu nedostatek   genetika   imunologie   MeSH
• ubikvitin genetika   imunologie   MeSH
• ubikvitinace MeSH
• ubikvitinligasy genetika   imunologie   MeSH
• zárodečné mutace * MeSH
• Check Tag
• dítě MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

The collapsin response mediator protein (CRMP) family proteins are intracellular mediators of neurotrophic factors regulating neurite structure/spine formation and are essential for dendrite patterning and directional axonal pathfinding during brain developmental processes. Among this family, CRMP5/DPYSL5 plays a significant role in neuronal migration, axonal guidance, dendrite outgrowth, and synapse formation by interacting with microtubules. Here, we report the identification of missense mutations in DPYSL5 in nine individuals with brain malformations, including corpus callosum agenesis and/or posterior fossa abnormalities, associated with variable degrees of intellectual disability. A recurrent de novo p.Glu41Lys variant was found in eight unrelated patients, and a p.Gly47Arg variant was identified in one individual from the first family reported with Ritscher-Schinzel syndrome. Functional analyses of the two missense mutations revealed impaired dendritic outgrowth processes in young developing hippocampal primary neuronal cultures. We further demonstrated that these mutations, both located in the same loop on the surface of DPYSL5 monomers and oligomers, reduced the interaction of DPYSL5 with neuronal cytoskeleton-associated proteins MAP2 and βIII-tubulin. Our findings collectively indicate that the p.Glu41Lys and p.Gly47Arg variants impair DPYSL5 function on dendritic outgrowth regulation by preventing the formation of the ternary complex with MAP2 and βIII-tubulin, ultimately leading to abnormal brain development. This study adds DPYSL5 to the list of genes implicated in brain malformation and in neurodevelopmental disorders.

• MeSH
• ageneze corpus callosum diagnostické zobrazování   genetika   MeSH
• dítě MeSH
• dospělí MeSH
• hydrolasy chemie   genetika   MeSH
• lidé MeSH
• mentální retardace diagnostické zobrazování   genetika   MeSH
• missense mutace genetika   MeSH
• mladý dospělý MeSH
• molekulární modely MeSH
• mozeček abnormality   diagnostické zobrazování   MeSH
• neurovývojové poruchy diagnostické zobrazování   genetika   MeSH
• předškolní dítě MeSH
• proteiny asociované s mikrotubuly chemie   genetika   metabolismus   MeSH
• tubulin metabolismus   MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

Congenital heart disease is the most common type of birth defect, accounting for one-third of all congenital anomalies. Using whole-exome sequencing of 2718 patients with congenital heart disease and a search in GeneMatcher, we identified 30 patients from 21 unrelated families of different ancestries with biallelic phospholipase D1 (PLD1) variants who presented predominantly with congenital cardiac valve defects. We also associated recessive PLD1 variants with isolated neonatal cardiomyopathy. Furthermore, we established that p.I668F is a founder variant among Ashkenazi Jews (allele frequency of ~2%) and describe the phenotypic spectrum of PLD1-associated congenital heart defects. PLD1 missense variants were overrepresented in regions of the protein critical for catalytic activity, and, correspondingly, we observed a strong reduction in enzymatic activity for most of the mutant proteins in an enzymatic assay. Finally, we demonstrate that PLD1 inhibition decreased endothelial-mesenchymal transition, an established pivotal early step in valvulogenesis. In conclusion, our study provides a more detailed understanding of disease mechanisms and phenotypic expression associated with PLD1 loss of function.

• MeSH
• alely * MeSH
• fosfolipasa D * genetika   metabolismus   MeSH
• lidé MeSH
• mutace ztráty funkce * MeSH
• nemoci srdečních chlopní * enzymologie   genetika   MeSH
• vrozené srdeční vady * enzymologie   genetika   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH