@article {1008, title = {SPEN haploinsufficiency causes a neurodevelopmental disorder overlapping proximal 1p36 deletion syndrome with an episignature of X chromosomes in females.}, journal = {Am J Hum Genet}, volume = {108}, year = {2021}, month = {2021 03 04}, pages = {502-516}, abstract = {

Deletion 1p36 (del1p36) syndrome is the most common human disorder resulting from a terminal autosomal deletion. This condition is molecularly and clinically heterogeneous. Deletions involving two non-overlapping regions, known as the distal (telomeric) and proximal (centromeric) critical regions, are sufficient to cause the majority of the recurrent clinical features, although with different facial features and dysmorphisms. SPEN encodes a transcriptional repressor commonly deleted in proximal del1p36 syndrome and is located centromeric to the proximal 1p36 critical region. Here, we used clinical data from 34 individuals with truncating variants in SPEN to define a neurodevelopmental disorder presenting with features that overlap considerably with those of proximal del1p36 syndrome. The clinical profile of this disease includes developmental delay/intellectual disability, autism spectrum disorder, anxiety, aggressive behavior, attention deficit disorder, hypotonia, brain and spine anomalies, congenital heart defects, high/narrow palate, facial dysmorphisms, and obesity/increased BMI, especially in females. SPEN also emerges as a relevant gene for del1p36 syndrome by co-expression analyses. Finally, we show that haploinsufficiency of SPEN is associated with a distinctive DNA methylation episignature of the X chromosome in affected females, providing further evidence of a specific contribution of the protein to the epigenetic control of this chromosome, and a paradigm of an X chromosome-specific episignature that classifies syndromic traits. We conclude that SPEN is required for multiple developmental processes and SPEN haploinsufficiency is a major contributor to a disorder associated with deletions centromeric to the previously established 1p36 critical regions.

}, keywords = {Adolescent, Autism Spectrum Disorder, Child, Child, Preschool, Chromosome Deletion, Chromosome Disorders, Chromosomes, Human, Pair 1, Chromosomes, Human, X, DNA Methylation, DNA-Binding Proteins, Epigenesis, Genetic, Female, Haploinsufficiency, Humans, Intellectual Disability, Male, Neurodevelopmental Disorders, Phenotype, RNA-Binding Proteins, Young Adult}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2021.01.015}, author = {Radio, Francesca Clementina and Pang, Kaifang and Ciolfi, Andrea and Levy, Michael A and Hernandez-Garcia, Andres and Pedace, Lucia and Pantaleoni, Francesca and Liu, Zhandong and de Boer, Elke and Jackson, Adam and Bruselles, Alessandro and McConkey, Haley and Stellacci, Emilia and Lo Cicero, Stefania and Motta, Marialetizia and Carrozzo, Rosalba and Dentici, Maria Lisa and McWalter, Kirsty and Desai, Megha and Monaghan, Kristin G and Telegrafi, Aida and Philippe, Christophe and Vitobello, Antonio and Au, Margaret and Grand, Katheryn and Sanchez-Lara, Pedro A and Baez, Joanne and Lindstrom, Kristin and Kulch, Peggy and Sebastian, Jessica and Madan-Khetarpal, Suneeta and Roadhouse, Chelsea and MacKenzie, Jennifer J and Monteleone, Berrin and Saunders, Carol J and Jean Cuevas, July K and Cross, Laura and Zhou, Dihong and Hartley, Taila and Sawyer, Sarah L and Monteiro, Fabiola Paoli and Secches, Tania Vertemati and Kok, Fernando and Schultz-Rogers, Laura E and Macke, Erica L and Morava, Eva and Klee, Eric W and Kemppainen, Jennifer and Iascone, Maria and Selicorni, Angelo and Tenconi, Romano and Amor, David J and Pais, Lynn and Gallacher, Lyndon and Turnpenny, Peter D and Stals, Karen and Ellard, Sian and Cabet, Sara and Lesca, Gaetan and Pascal, Joset and Steindl, Katharina and Ravid, Sarit and Weiss, Karin and Castle, Alison M R and Carter, Melissa T and Kalsner, Louisa and de Vries, Bert B A and van Bon, Bregje W and Wevers, Marijke R and Pfundt, Rolph and Stegmann, Alexander P A and Kerr, Bronwyn and Kingston, Helen M and Chandler, Kate E and Sheehan, Willow and Elias, Abdallah F and Shinde, Deepali N and Towne, Meghan C and Robin, Nathaniel H and Goodloe, Dana and Vanderver, Adeline and Sherbini, Omar and Bluske, Krista and Hagelstrom, R Tanner and Zanus, Caterina and Faletra, Flavio and Musante, Luciana and Kurtz-Nelson, Evangeline C and Earl, Rachel K and Anderlid, Britt-Marie and Morin, Gilles and van Slegtenhorst, Marjon and Diderich, Karin E M and Brooks, Alice S and Gribnau, Joost and Boers, Ruben G and Finestra, Teresa Robert and Carter, Lauren B and Rauch, Anita and Gasparini, Paolo and Boycott, Kym M and Barakat, Tahsin Stefan and GrAHm, John M and Faivre, Laurence and Banka, Siddharth and Wang, Tianyun and Eichler, Evan E and Priolo, Manuela and Dallapiccola, Bruno and Vissers, Lisenka E L M and Sadikovic, Bekim and Scott, Daryl A and Holder, Jimmy Lloyd and Tartaglia, Marco} } @article {786, title = {Further delineation of the clinical spectrum of KAT6B disorders and allelic series of pathogenic variants.}, journal = {Genet Med}, volume = {22}, year = {2020}, month = {2020 08}, pages = {1338-1347}, abstract = {

PURPOSE: Genitopatellar syndrome and Say-Barber-Biesecker-Young-Simpson syndrome are caused by variants in the KAT6B gene and are part of a broad clinical spectrum called KAT6B disorders, whose variable expressivity is increasingly being recognized.

METHODS: We herein present the phenotypes of 32 previously unreported individuals with a molecularly confirmed diagnosis of a KAT6B disorder, report 24 new pathogenic KAT6B variants, and review phenotypic information available on all published individuals with this condition. We also suggest a classification of clinical subtypes within the KAT6B disorder spectrum.

RESULTS: We demonstrate that cerebral anomalies, optic nerve hypoplasia, neurobehavioral difficulties, and distal limb anomalies other than long thumbs and great toes, such as polydactyly, are more frequently observed than initially reported. Intestinal malrotation and its serious consequences can be present in affected individuals. Additionally, we identified four children with Pierre Robin sequence, four individuals who had increased nuchal translucency/cystic hygroma prenatally, and two fetuses with severe renal anomalies leading to renal failure. We also report an individual in which a pathogenic variant was inherited from a mildly affected parent.

CONCLUSION: Our work provides a comprehensive review and expansion of the genotypic and phenotypic spectrum of KAT6B disorders that will assist clinicians in the assessment, counseling, and management of affected individuals.

}, keywords = {Blepharophimosis, Exons, Histone Acetyltransferases, Humans, Intellectual Disability, Mutation}, issn = {1530-0366}, doi = {10.1038/s41436-020-0811-8}, author = {Zhang, Li Xin and Lemire, Gabrielle and Gonzaga-Jauregui, Claudia and Molidperee, Sirinart and Galaz-Montoya, Carolina and Liu, David S and Verloes, Alain and Shillington, Amelle G and Izumi, Kosuke and Ritter, Alyssa L and Keena, Beth and Zackai, Elaine and Li, Dong and Bhoj, Elizabeth and Tarpinian, Jennifer M and Bedoukian, Emma and Kukolich, Mary K and Innes, A Micheil and Ediae, Grace U and Sawyer, Sarah L and Nair, Karippoth Mohandas and Soumya, Para Chottil and Subbaraman, Kinattinkara R and Probst, Frank J and Bassetti, Jennifer A and Sutton, Reid V and Gibbs, Richard A and Brown, Chester and Boone, Philip M and Holm, Ingrid A and Tartaglia, Marco and Ferrero, Giovanni Battista and Niceta, Marcello and Dentici, Maria Lisa and Radio, Francesca Clementina and Keren, Boris and Wells, Constance F and Coubes, Christine and Laquerri{\`e}re, Annie and Aziza, Jacqueline and Dubucs, Charlotte and Nampoothiri, Sheela and Mowat, David and Patel, Millan S and Bracho, Ana and Cammarata-Scalisi, Francisco and Gezdirici, Alper and Fern{\'a}ndez-Ja{\'e}n, Alberto and Hauser, Natalie and Zarate, Yuri A and Bosanko, Katherine A and Dieterich, Klaus and Carey, John C and Chong, Jessica X and Nickerson, Deborah A and Bamshad, Michael J and Lee, Brendan H and Yang, Xiang-Jiao and Lupski, James R and Campeau, Philippe M} } @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 {697, title = {De Novo Variants Disturbing the Transactivation Capacity of POU3F3 Cause a Characteristic Neurodevelopmental Disorder.}, journal = {Am J Hum Genet}, volume = {105}, year = {2019}, month = {2019 Aug 01}, pages = {403-412}, abstract = {

POU3F3, also referred to as Brain-1, is a well-known transcription factor involved in the development of the central nervous system, but it has not previously been associated with a neurodevelopmental disorder. Here, we report the identification of 19 individuals with heterozygous POU3F3 disruptions, most of which are de novo variants. All individuals had developmental delays and/or intellectual disability and impairments in speech and language skills. Thirteen individuals had characteristic low-set, prominent, and/or cupped ears. Brain abnormalities were observed in seven of eleven MRI reports. POU3F3 is an intronless gene, insensitive to nonsense-mediated decay, and 13 individuals carried protein-truncating variants. All truncating variants that we tested in cellular models led to aberrant subcellular localization of the encoded protein. Luciferase assays demonstrated negative effects of these alleles on transcriptional activation of a reporter with a FOXP2-derived binding motif. In addition to the loss-of-function variants, five individuals had missense variants that clustered at specific positions within the functional domains, and one small in-frame deletion was identified. Two missense variants showed reduced transactivation capacity in our assays, whereas one variant displayed gain-of-function effects, suggesting a distinct pathophysiological mechanism. In bioluminescence resonance energy transfer (BRET) interaction assays, all the truncated POU3F3 versions that we tested had significantly impaired dimerization capacities, whereas all missense variants showed unaffected dimerization with wild-type POU3F3. Taken together, our identification and functional cell-based analyses of pathogenic variants in POU3F3, coupled with a clinical characterization, implicate disruptions of this gene in a characteristic neurodevelopmental disorder.

}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2019.06.007}, author = {Snijders Blok, Lot and Kleefstra, Tjitske and Venselaar, Hanka and Maas, Saskia and Kroes, Hester Y and Lachmeijer, Augusta M A and van Gassen, Koen L I and Firth, Helen V and Tomkins, Susan and Bodek, Simon and {\~O}unap, Katrin and Wojcik, Monica H and Cunniff, Christopher and Bergstrom, Katherine and Powis, Z{\"o}e and Tang, Sha and Shinde, Deepali N and Au, Catherine and Iglesias, Alejandro D and Izumi, Kosuke and Leonard, Jacqueline and Abou Tayoun, Ahmad and Baker, Samuel W and Tartaglia, Marco and Niceta, Marcello and Dentici, Maria Lisa and Okamoto, Nobuhiko and Miyake, Noriko and Matsumoto, Naomichi and Vitobello, Antonio and Faivre, Laurence and Philippe, Christophe and Gilissen, Christian and Wiel, Laurens and Pfundt, Rolph and Deriziotis, Pelagia and Brunner, Han G and Fisher, Simon E} } @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 {422, title = {Mutations in Fibronectin Cause a Subtype of Spondylometaphyseal Dysplasia with "Corner Fractures".}, journal = {Am J Hum Genet}, volume = {101}, year = {2017}, month = {2017 Nov 02}, pages = {815-823}, abstract = {

Fibronectin is a master organizer of extracellular matrices (ECMs) and promotes the assembly of collagens, fibrillin-1, and other proteins. It is also known to play roles in skeletal tissues through its secretion by osteoblasts, chondrocytes, and mesenchymal cells. Spondylometaphyseal dysplasias (SMDs) comprise a diverse group of skeletal dysplasias and often manifest as short stature, growth-plate irregularities, and vertebral anomalies, such as scoliosis. By comparing the exomes of individuals with SMD with the radiographic appearance of "corner fractures" at metaphyses, we identified three individuals with fibronectin (FN1) variants affecting highly conserved residues. Furthermore, using matching tools and the SkelDys emailing list, we identified other individuals with de novo~FN1 variants and a similar phenotype. The severe scoliosis in most individuals and rare developmental coxa vara distinguish individuals with FN1 mutations from those with classical Sutcliffe-type SMD. To study functional consequences of these FN1 mutations on the protein level, we introduced three disease-associated missense variants (p.Cys87Phe [c.260G>T], p.Tyr240Asp [c.718T>G], and p.Cys260Gly [c.778T>G]) into a recombinant secreted N-terminal 70~kDa fragment (rF70K) and the full-length fibronectin (rFN). The wild-type rF70K and rFN were secreted into the culture medium, whereas all mutant proteins were either not secreted or secreted at significantly lower amounts. Immunofluorescence analysis demonstrated increased intracellular retention of the mutant proteins. In summary, FN1 mutations that cause defective fibronectin secretion are found in SMD, and we thus provide additional evidence for a critical function of fibronectin in cartilage and bone.

}, keywords = {Adolescent, Adult, Bone and Bones, Bone Diseases, Developmental, Cartilage, Child, Child, Preschool, Exome, Female, Fibronectins, Fractures, Bone, Humans, Male, Mutation, Osteochondrodysplasias, Phenotype, Scoliosis}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2017.09.019}, author = {Lee, Chae Syng and Fu, He and Baratang, Nissan and Rousseau, Justine and Kumra, Heena and Sutton, V Reid and Niceta, Marcello and Ciolfi, Andrea and Yamamoto, Guilherme and Bertola, D{\'e}bora and Marcelis, Carlo L and Lugtenberg, Dorien and Bartuli, Andrea and Kim, Choel and Hoover-Fong, Julie and Sobreira, Nara and Pauli, Richard and Bacino, Carlos and Krakow, Deborah and Parboosingh, Jillian and Yap, Patrick and Kariminejad, Ariana and McDonald, Marie T and Aracena, Mariana I and Lausch, Ekkehart and Unger, Sheila and Superti-Furga, Andrea and Lu, James T and Cohn, Dan H and Tartaglia, Marco and Lee, Brendan H and Reinhardt, Dieter P and Campeau, Philippe M} } @article {70, title = {Recessive Inactivating Mutations in TBCK, Encoding a Rab GTPase-Activating Protein, Cause Severe Infantile Syndromic Encephalopathy.}, journal = {Am J Hum Genet}, volume = {98}, year = {2016}, month = {2016 Apr 07}, pages = {772-81}, abstract = {

Infantile encephalopathies are a group of clinically and biologically heterogeneous disorders for which the genetic basis remains largely unknown. Here, we report a syndromic neonatal encephalopathy characterized by profound developmental disability, severe hypotonia, seizures, diminished respiratory drive requiring mechanical ventilation, brain atrophy, dysgenesis of the corpus callosum, cerebellar vermis hypoplasia, and facial dysmorphism. Biallelic inactivating mutations in TBCK (TBC1-domain-containing kinase) were independently identified by whole-exome sequencing as the cause of this condition in four unrelated families. Matching these families was facilitated by the sharing of phenotypic profiles and WES data in a recently released web-based tool (Geno2MP) that links phenotypic information to rare variants in families with Mendelian traits. TBCK is a putative GTPase-activating protein (GAP) for small GTPases of the Rab family and has been shown to control cell growth and proliferation, actin-cytoskeleton dynamics, and mTOR signaling. Two of the three mutations (c.376C>T [p.Arg126(*)] and c.1363A>T [p.Lys455(*)]) are predicted to truncate the protein, and loss of the major TBCK isoform was confirmed in primary fibroblasts from one affected individual. The third mutation, c.1532G>A (p.Arg511His), alters a conserved residue within the TBC1 domain. Structural analysis implicated Arg511 as a required residue for Rab-GAP function, and in~silico homology modeling predicted impaired GAP function in the corresponding mutant. These results suggest that loss of Rab-GAP activity is the underlying mechanism of disease. In contrast to other disorders caused by dysregulated mTOR signaling associated with focal or global brain overgrowth, impaired TBCK function results in progressive loss of brain volume.

}, keywords = {Adolescent, Alleles, Amino Acid Sequence, Brain Diseases, Child, Child, Preschool, Corpus Callosum, Female, GTPase-Activating Proteins, Humans, Magnetic Resonance Imaging, Male, Molecular Sequence Data, Mutation, Pedigree, Protein Conformation, Protein-Serine-Threonine Kinases, Signal Transduction, TOR Serine-Threonine Kinases}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.01.016}, author = {Chong, Jessica X and Caputo, Viviana and Phelps, Ian G and Stella, Lorenzo and Worgan, Lisa and Dempsey, Jennifer C and Nguyen, Alina and Leuzzi, Vincenzo and Webster, Richard and Pizzuti, Antonio and Marvin, Colby T and Ishak, Gisele E and Ardern-Holmes, Simone and Richmond, Zara and Bamshad, Michael J and Ortiz-Gonzalez, Xilma R and Tartaglia, Marco and Chopra, Maya and Doherty, Dan} } @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} }