@article {687, title = {Aberrant Function of the C-Terminal Tail of HIST1H1E Accelerates Cellular Senescence and Causes Premature Aging.}, journal = {Am J Hum Genet}, volume = {105}, year = {2019}, month = {2019 Sep 05}, pages = {493-508}, abstract = {

Histones mediate dynamic packaging of nuclear DNA in chromatin, a process that is precisely controlled to guarantee efficient compaction of the genome and proper chromosomal segregation during cell division and to accomplish DNA replication, transcription, and repair. Due to the important structural and regulatory roles played by histones, it is not surprising that histone functional dysregulation or aberrant levels of histones can have severe consequences for multiple cellular processes and ultimately might affect development or contribute to cell transformation. Recently, germline frameshift mutations involving the C-terminal tail of HIST1H1E, which is a widely expressed member of the linker histone family and facilitates higher-order chromatin folding, have been causally linked to an as-yet poorly defined syndrome that includes intellectual disability. We report that these mutations result in stable proteins that reside in the nucleus, bind to chromatin, disrupt proper compaction of DNA, and are associated with a specific methylation pattern. Cells expressing these mutant proteins have a dramatically reduced proliferation rate and competence, hardly enter into the S phase, and undergo accelerated senescence. Remarkably, clinical assessment of a relatively large cohort of subjects sharing these mutations revealed a premature aging phenotype as a previously unrecognized feature of the disorder. Our findings identify a direct link between aberrant chromatin remodeling, cellular senescence, and accelerated aging.

}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2019.07.007}, author = {Flex, Elisabetta and Martinelli, Simone and Van Dijck, Anke and Ciolfi, Andrea and Cecchetti, Serena and Coluzzi, Elisa and Pannone, Luca and Andreoli, Cristina and Radio, Francesca Clementina and Pizzi, Simone and Carpentieri, Giovanna and Bruselles, Alessandro and Catanzaro, Giuseppina and Pedace, Lucia and Miele, Evelina and Carcarino, Elena and Ge, Xiaoyan and Chijiwa, Chieko and Lewis, M E Suzanne and Meuwissen, Marije and Kenis, Sandra and Van der Aa, Nathalie and Larson, Austin and Brown, Kathleen and Wasserstein, Melissa P and Skotko, Brian G and Begtrup, Amber and Person, Richard and Karayiorgou, Maria and Roos, J Louw and Van Gassen, Koen L and Koopmans, Marije and Bijlsma, Emilia K and Santen, Gijs W E and Barge-Schaapveld, Daniela Q C M and Ruivenkamp, Claudia A L and Hoffer, Mariette J V and Lalani, Seema R and Streff, Haley and Craigen, William J and Graham, Brett H and van den Elzen, Annette P M and Kamphuis, Daan J and {\~O}unap, Katrin and Reinson, Karit and Pajusalu, Sander and Wojcik, Monica H and Viberti, Clara and Di Gaetano, Cornelia and Bertini, Enrico and Petrucci, Simona and De Luca, Alessandro and Rota, Rossella and Ferretti, Elisabetta and Matullo, Giuseppe and Dallapiccola, Bruno and Sgura, Antonella and Walkiewicz, Magdalena and Kooy, R Frank and Tartaglia, Marco} } @article {543, title = {Functional Dysregulation of CDC42 Causes Diverse Developmental Phenotypes.}, journal = {Am J Hum Genet}, volume = {102}, year = {2018}, month = {2018 Feb 01}, pages = {309-320}, abstract = {

Exome sequencing has markedly enhanced the discovery of genes implicated in Mendelian disorders, particularly for individuals in whom a known clinical entity could not be assigned. This has led to the recognition that phenotypic heterogeneity resulting from allelic mutations occurs more commonly than previously appreciated. Here, we report that missense variants in CDC42, a gene encoding a small GTPase functioning as an intracellular signaling node, underlie a clinically heterogeneous group of phenotypes characterized by variable growth dysregulation, facial dysmorphism, and neurodevelopmental, immunological, and hematological anomalies, including a phenotype resembling Noonan syndrome, a developmental disorder caused by dysregulated RAS signaling. In silico, in~vitro, and in~vivo analyses demonstrate that mutations variably perturb CDC42 function by altering the switch between the active and inactive states of the GTPase and/or affecting CDC42 interaction with effectors, and differentially disturb cellular and developmental processes. These findings reveal the remarkably variable impact that dominantly acting CDC42 mutations have on cell function and development, creating challenges in syndrome definition, and exemplify the importance of functional profiling for syndrome recognition and delineation.

}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2017.12.015}, author = {Martinelli, Simone and Krumbach, Oliver H F and Pantaleoni, Francesca and Coppola, Simona and Amin, Ehsan and Pannone, Luca and Nouri, Kazem and Farina, Luciapia and Dvorsky, Radovan and Lepri, Francesca and Buchholzer, Marcel and Konopatzki, Raphael and Walsh, Laurence and Payne, Katelyn and Pierpont, Mary Ella and Vergano, Samantha Schrier and Langley, Katherine G and Larsen, Douglas and Farwell, Kelly D and Tang, Sha and Mroske, Cameron and Gallotta, Ivan and Di Schiavi, Elia and Della Monica, Matteo and Lugli, Licia and Rossi, Cesare and Seri, Marco and Cocchi, Guido and Henderson, Lindsay and Baskin, Berivan and Alders, Marielle and Mendoza-Londono, Roberto and Dupuis, Lucie and Nickerson, Deborah A and Chong, Jessica X and Meeks, Naomi and Brown, Kathleen and Causey, Tahnee and Cho, Megan T and Demuth, Stephanie and Digilio, Maria Cristina and Gelb, Bruce D and Bamshad, Michael J and Zenker, Martin and Ahmadian, Mohammad Reza and Hennekam, Raoul C and Tartaglia, Marco and Mirzaa, Ghayda M} } @article {453, title = {High Rate of Recurrent De Novo Mutations in Developmental and Epileptic Encephalopathies.}, journal = {Am J Hum Genet}, volume = {101}, year = {2017}, month = {2017 Nov 02}, pages = {664-685}, abstract = {

Developmental and epileptic encephalopathy (DEE) is a group of conditions characterized by the co-occurrence of epilepsy and intellectual disability (ID), typically with developmental plateauing or regression associated with frequent epileptiform activity. The cause of DEE remains unknown in the majority of cases. We performed whole-genome sequencing (WGS) in 197 individuals with unexplained DEE and pharmaco-resistant seizures and in their unaffected parents. We focused our attention on de novo mutations (DNMs) and identified candidate genes containing such variants. We sought to identify additional subjects with DNMs in these genes by performing targeted sequencing in another series of individuals with DEE and by mining various sequencing datasets. We also performed meta-analyses to document enrichment of DNMs in candidate genes by leveraging our WGS dataset with those of several DEE and ID series. By combining these strategies, we were able to provide a causal link between DEE and the following genes: NTRK2, GABRB2, CLTC, DHDDS, NUS1, RAB11A, GABBR2, and SNAP25. Overall, we established a molecular diagnosis in 63/197 (32\%) individuals in our WGS series. The main cause of DEE in these individuals was de novo point mutations (53/63 solved cases), followed by inherited mutations (6/63 solved cases) and de novo CNVs (4/63 solved cases). De novo missense variants explained a larger proportion of individuals in our series than in other series that were primarily ascertained because of ID. Moreover, these DNMs were more frequently recurrent than those identified in ID series. These observations indicate that the genetic landscape of DEE might be different from that of ID without epilepsy.

}, keywords = {Brain Diseases, Child, Child, Preschool, Epilepsy, Female, Genome, Human, Genome-Wide Association Study, Humans, Intellectual Disability, Male, Mutation, Recurrence, Seizures}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2017.09.008}, author = {Hamdan, Fadi F and Myers, Candace T and Cossette, Patrick and Lemay, Philippe and Spiegelman, Dan and Laporte, Alexandre Dionne and Nassif, Christina and Diallo, Ousmane and Monlong, Jean and Cadieux-Dion, Maxime and Dobrzeniecka, Sylvia and Meloche, Caroline and Retterer, Kyle and Cho, Megan T and Rosenfeld, Jill A and Bi, Weimin and Massicotte, Christine and Miguet, Marguerite and Brunga, Ledia and Regan, Brigid M and Mo, Kelly and Tam, Cory and Schneider, Amy and Hollingsworth, Georgie and FitzPatrick, David R and Donaldson, Alan and Canham, Natalie and Blair, Edward and Kerr, Bronwyn and Fry, Andrew E and Thomas, Rhys H and Shelagh, Joss and Hurst, Jane A and Brittain, Helen and Blyth, Moira and Lebel, Robert Roger and Gerkes, Erica H and Davis-Keppen, Laura and Stein, Quinn and Chung, Wendy K and Dorison, Sara J and Benke, Paul J and Fassi, Emily and Corsten-Janssen, Nicole and Kamsteeg, Erik-Jan and Mau-Them, Frederic T and Bruel, Ange-Line and Verloes, Alain and {\~O}unap, Katrin and Wojcik, Monica H and Albert, Dara V F and Venkateswaran, Sunita and Ware, Tyson and Jones, Dean and Liu, Yu-Chi and Mohammad, Shekeeb S and Bizargity, Peyman and Bacino, Carlos A and Leuzzi, Vincenzo and Martinelli, Simone and Dallapiccola, Bruno and Tartaglia, Marco and Blumkin, Lubov and Wierenga, Klaas J and Purcarin, Gabriela and O{\textquoteright}Byrne, James J and Stockler, Sylvia and Lehman, Anna and Keren, Boris and Nougues, Marie-Christine and Mignot, Cyril and Auvin, St{\'e}phane and Nava, Caroline and Hiatt, Susan M and Bebin, Martina and Shao, Yunru and Scaglia, Fernando and Lalani, Seema R and Frye, Richard E and Jarjour, Imad T and Jacques, St{\'e}phanie and Boucher, Renee-Myriam and Riou, Emilie and Srour, Myriam and Carmant, Lionel and Lortie, Anne and Major, Philippe and Diadori, Paola and Dubeau, Fran{\c c}ois and D{\textquoteright}Anjou, Guy and Bourque, Guillaume and Berkovic, Samuel F and Sadleir, Lynette G and Campeau, Philippe M and Kibar, Zoha and Lafreni{\`e}re, Ronald G and Girard, Simon L and Mercimek-Mahmutoglu, Saadet and Boelman, Cyrus and Rouleau, Guy A and Scheffer, Ingrid E and Mefford, Heather C and Andrade, Danielle M and Rossignol, Elsa and Minassian, Berge A and Michaud, Jacques L} } @article {147, title = {Activating Mutations Affecting the Dbl Homology Domain of SOS2 Cause Noonan Syndrome.}, journal = {Hum Mutat}, volume = {36}, year = {2015}, month = {2015 Nov}, pages = {1080-7}, abstract = {

The RASopathies constitute a family of autosomal-dominant disorders whose major features include facial dysmorphism, cardiac defects, reduced postnatal growth, variable cognitive deficits, ectodermal and skeletal anomalies, and susceptibility to certain malignancies. Noonan syndrome (NS), the commonest RASopathy, is genetically heterogeneous and caused by functional dysregulation of signal transducers and regulatory proteins with roles in the RAS/extracellular signal-regulated kinase (ERK) signal transduction pathway. Mutations in known disease genes account for approximately 80\% of affected individuals. Here, we report that missense mutations altering Son of Sevenless, Drosophila, homolog 2 (SOS2), which encodes a RAS guanine nucleotide exchange factor, occur in a small percentage of subjects with NS. Four missense mutations were identified in five unrelated sporadic cases and families transmitting NS. Disease-causing mutations affected three conserved residues located in the Dbl homology (DH) domain, of which two are directly involved in the intramolecular binding network maintaining SOS2 in its autoinhibited conformation. All mutations were found to promote enhanced signaling from RAS to ERK. Similar to NS-causing SOS1 mutations, the phenotype associated with SOS2 defects is characterized by normal development and growth, as well as marked ectodermal involvement. Unlike SOS1 mutations, however, those in SOS2 are restricted to the DH domain.

}, keywords = {Adolescent, Adult, Alleles, Amino Acid Substitution, Child, DNA Mutational Analysis, Exome, Facies, Female, Genetic Association Studies, Genotype, Humans, Male, Models, Molecular, Mutation, Noonan Syndrome, Phenotype, Protein Conformation, Protein Interaction Domains and Motifs, Son of Sevenless Proteins, Young Adult}, issn = {1098-1004}, doi = {10.1002/humu.22834}, author = {Cordeddu, Viviana and Yin, Jiani C and Gunnarsson, Cecilia and Virtanen, Carl and Drunat, S{\'e}verine and Lepri, Francesca and De Luca, Alessandro and Rossi, Cesare and Ciolfi, Andrea and Pugh, Trevor J and Bruselles, Alessandro and Priest, James R and Pennacchio, Len A and Lu, Zhibin and Danesh, Arnavaz and Quevedo, Rene and Hamid, Alaa and Martinelli, Simone and Pantaleoni, Francesca and Gnazzo, Maria and Daniele, Paola and Lissewski, Christina and Bocchinfuso, Gianfranco and Stella, Lorenzo and Odent, Sylvie and Philip, Nicole and Faivre, Laurence and Vlckova, Marketa and Seemanova, Eva and Digilio, Cristina and Zenker, Martin and Zampino, Giuseppe and Verloes, Alain and Dallapiccola, Bruno and Roberts, Amy E and Cav{\'e}, H{\'e}l{\`e}ne and Gelb, Bruce D and Neel, Benjamin G and Tartaglia, Marco} }