@article {974, title = {Variants in GNAI1 cause a syndrome associated with variable features including developmental delay, seizures, and hypotonia.}, journal = {Genet Med}, volume = {23}, year = {2021}, month = {2021 05}, pages = {881-887}, abstract = {

PURPOSE: Neurodevelopmental disorders (NDDs) encompass a spectrum of genetically heterogeneous disorders with features that commonly include developmental delay, intellectual disability, and autism spectrum disorders. We sought to delineate the molecular and phenotypic spectrum of a novel neurodevelopmental disorder caused by variants in the GNAI1 gene.

METHODS: Through large cohort trio-based exome sequencing and international data-sharing, we identified 24 unrelated individuals with NDD phenotypes and a variant in GNAI1, which encodes the inhibitory Gαi1 subunit of heterotrimeric G-proteins. We collected detailed genotype and phenotype information for each affected individual.

RESULTS: We identified 16 unique variants in GNAI1 in 24 affected individuals; 23 occurred de novo and 1 was inherited from a mosaic parent. Most affected individuals have a severe neurodevelopmental disorder. Core features include global developmental delay, intellectual disability, hypotonia, and epilepsy.

CONCLUSION: This collaboration establishes GNAI1 variants as a cause of NDDs. GNAI1-related NDD is most often characterized by severe to profound delays, hypotonia, epilepsy that ranges from self-limiting to intractable, behavior problems, and variable mild dysmorphic features.

}, keywords = {Child, Developmental Disabilities, Humans, Intellectual Disability, Muscle Hypotonia, Neurodevelopmental Disorders, Seizures, Whole Exome Sequencing}, issn = {1530-0366}, doi = {10.1038/s41436-020-01076-8}, author = {Muir, Alison M and Gardner, Jennifer F and van Jaarsveld, Richard H and de Lange, Iris M and van der Smagt, Jasper J and Wilson, Golder N and Dubbs, Holly and Goldberg, Ethan M and Zitano, Lia and Bupp, Caleb and Martinez, Jose and Srour, Myriam and Accogli, Andrea and Alhakeem, Afnan and Meltzer, Meira and Gropman, Andrea and Brewer, Carole and Caswell, Richard C and Montgomery, Tara and McKenna, Caoimhe and McKee, Shane and Powell, Corinna and Vasudevan, Pradeep C and Brady, Angela F and Joss, Shelagh and Tysoe, Carolyn and Noh, Grace and Tarnopolsky, Mark and Brady, Lauren and Zafar, Muhammad and Schrier Vergano, Samantha A and Murray, Brianna and Sawyer, Lindsey and Hainline, Bryan E and Sapp, Katherine and DeMarzo, Danielle and Huismann, Darcy J and Wentzensen, Ingrid M and Schnur, Rhonda E and Monaghan, Kristin G and Juusola, Jane and Rhodes, Lindsay and Dobyns, William B and Lecoquierre, Francois and Goldenberg, Alice and Polster, Tilman and Axer-Schaefer, Susanne and Platzer, Konrad and Kl{\"o}ckner, Chiara and Hoffman, Trevor L and MacArthur, Daniel G and O{\textquoteright}Leary, Melanie C and VanNoy, Grace E and England, Eleina and Varghese, Vinod C and Mefford, Heather C} } @article {574, title = {Biallelic mutations in valyl-tRNA synthetase gene VARS are associated with a progressive neurodevelopmental epileptic encephalopathy.}, journal = {Nat Commun}, volume = {10}, year = {2019}, month = {2019 02 12}, pages = {707}, abstract = {

Aminoacyl-tRNA synthetases (ARSs) function to transfer amino acids to cognate tRNA molecules, which are required for protein translation. To date, biallelic mutations in 31 ARS genes are known to cause recessive, early-onset severe multi-organ diseases. VARS encodes the only known valine cytoplasmic-localized aminoacyl-tRNA synthetase. Here, we report seven patients from five unrelated families with five different biallelic missense variants in VARS. Subjects present with a range of global developmental delay, epileptic encephalopathy and primary or progressive microcephaly. Longitudinal assessment demonstrates progressive cortical atrophy and white matter volume loss. Variants map to the VARS tRNA binding domain and adjacent to the anticodon domain, and disrupt highly conserved residues. Patient primary cells show intact VARS protein but reduced enzymatic activity, suggesting partial loss of function. The implication of VARS in pediatric neurodegeneration broadens the spectrum of human diseases due to mutations in tRNA synthetase genes.

}, keywords = {Alleles, Anticodon, Child, Child, Preschool, Disease Progression, Epilepsy, Female, Genetic Predisposition to Disease, Humans, Longitudinal Studies, Loss of Function Mutation, Male, Microcephaly, Models, Molecular, Mutation, Neurodevelopmental Disorders, Pedigree, Protein Biosynthesis, Protein Interaction Domains and Motifs, RNA, Transfer, Valine-tRNA Ligase, Whole Exome Sequencing, Whole Genome Sequencing}, issn = {2041-1723}, doi = {10.1038/s41467-018-07067-3}, author = {Friedman, Jennifer and Smith, Desiree E and Issa, Mahmoud Y and Stanley, Valentina and Wang, Rengang and Mendes, Marisa I and Wright, Meredith S and Wigby, Kristen and Hildreth, Amber and Crawford, John R and Koehler, Alanna E and Chowdhury, Shimul and Nahas, Shareef and Zhai, Liting and Xu, Zhiwen and Lo, Wing-Sze and James, Kiely N and Musaev, Damir and Accogli, Andrea and Guerrero, Kether and Tran, Luan T and Omar, Tarek E I and Ben-Omran, Tawfeg and Dimmock, David and Kingsmore, Stephen F and Salomons, Gajja S and Zaki, Maha S and Bernard, Genevi{\`e}ve and Gleeson, Joseph G} } @article {717, title = {De Novo Pathogenic Variants in N-cadherin Cause a Syndromic Neurodevelopmental Disorder with Corpus Collosum, Axon, Cardiac, Ocular, and Genital Defects.}, journal = {Am J Hum Genet}, volume = {105}, year = {2019}, month = {2019 Oct 03}, pages = {854-868}, abstract = {

Cadherins constitute a family of transmembrane proteins that mediate calcium-dependent cell-cell adhesion. The extracellular domain of cadherins consists of extracellular cadherin (EC) domains, separated by calcium binding sites. The EC interacts with other cadherin molecules in cis and in trans to mechanically hold apposing cell surfaces together. CDH2 encodes N-cadherin, whose essential roles in neural development include neuronal migration and axon pathfinding. However, CDH2 has not yet been linked to a Mendelian neurodevelopmental disorder. Here, we report de novo heterozygous pathogenic variants (seven missense, two frameshift) in CDH2 in nine individuals with a syndromic neurodevelopmental disorder characterized by global developmental delay and/or intellectual disability, variable axon pathfinding defects (corpus callosum agenesis or hypoplasia, mirror movements, Duane anomaly), and ocular, cardiac, and genital anomalies. All seven missense variants (c.1057G>A [p.Asp353Asn]; c.1789G>A [p.Asp597Asn]; c.1789G>T [p.Asp597Tyr]; c.1802A>C [p.Asn601Thr]; c.1839C>G [p.Cys613Trp]; c.1880A>G [p.Asp627Gly]; c.2027A>G [p.Tyr676Cys]) result in substitution of highly conserved residues, and six of seven cluster within EC domains 4 and 5. Four of the substitutions affect the calcium-binding site in the EC4-EC5 interdomain. We show that cells expressing these variants in the EC4-EC5 domains have a defect in cell-cell adhesion; this defect includes impaired binding in trans with N-cadherin-WT expressed on apposing cells. The two frameshift variants (c.2563_2564delCT [p.Leu855Valfs4]; c.2564_2567dupTGTT [p.Leu856Phefs5]) are predicted to lead to a truncated cytoplasmic domain. Our study demonstrates that de novo heterozygous variants in CDH2 impair the adhesive activity of N-cadherin, resulting in a multisystemic developmental disorder, that could be named ACOG syndrome (agenesis of corpus callosum, axon pathfinding, cardiac, ocular, and genital defects).

}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2019.09.005}, author = {Accogli, Andrea and Calabretta, Sara and St-Onge, Judith and Boudrahem-Addour, Nassima and Dionne-Laporte, Alexandre and Joset, Pascal and Azzarello-Burri, Silvia and Rauch, Anita and Krier, Joel and Fieg, Elizabeth and Pallais, Juan C and McConkie-Rosell, Allyn and McDonald, Marie and Freedman, Sharon F and Rivi{\`e}re, Jean-Baptiste and Lafond-Lapalme, Jo{\"e}l and Simpson, Brittany N and Hopkin, Robert J and Trimouille, Aur{\'e}lien and Van-Gils, Julien and Begtrup, Amber and McWalter, Kirsty and Delphine, Heron and Keren, Boris and Genevi{\`e}ve, David and Argilli, Emanuela and Sherr, Elliott H and Severino, Mariasavina and Rouleau, Guy A and Yam, Patricia T and Charron, Fr{\'e}d{\'e}ric and Srour, Myriam} } @article {678, title = {Heterozygous Variants in KMT2E Cause a Spectrum of Neurodevelopmental Disorders and Epilepsy.}, journal = {Am J Hum Genet}, volume = {104}, year = {2019}, month = {2019 Jun 06}, pages = {1210-1222}, abstract = {

We delineate a KMT2E-related neurodevelopmental disorder on the basis of 38 individuals in 36 families. This study includes 31 distinct heterozygous variants in KMT2E (28 ascertained from Matchmaker Exchange and three previously reported), and four individuals with chromosome 7q22.2-22.23 microdeletions encompassing KMT2E (one previously reported). Almost all variants occurred de novo, and most were truncating. Most affected individuals with protein-truncating variants presented with mild intellectual disability. One-quarter of individuals met criteria for autism. Additional common features include macrocephaly, hypotonia, functional gastrointestinal abnormalities, and a subtle facial gestalt. Epilepsy was present in about one-fifth of individuals with truncating variants and was responsive to treatment with anti-epileptic medications in almost all. More than 70\% of the individuals were male, and expressivity was variable by sex; epilepsy was more common in females and autism more common in males. The four individuals with microdeletions encompassing KMT2E generally presented similarly to those with truncating variants, but the degree of developmental delay was greater. The group of four individuals with missense variants in KMT2E presented with the most severe developmental delays. Epilepsy was present in all individuals with missense variants, often manifesting as treatment-resistant infantile epileptic encephalopathy. Microcephaly was also common in this group. Haploinsufficiency versus gain-of-function or dominant-negative effects specific to these missense variants in KMT2E might explain this divergence in phenotype, but requires independent validation. Disruptive variants in KMT2E are an under-recognized cause of neurodevelopmental abnormalities.

}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2019.03.021}, author = {O{\textquoteright}Donnell-Luria, Anne H and Pais, Lynn S and Faundes, V{\'\i}ctor and Wood, Jordan C and Sveden, Abigail and Luria, Victor and Abou Jamra, Rami and Accogli, Andrea and Amburgey, Kimberly and Anderlid, Britt Marie and Azzarello-Burri, Silvia and Basinger, Alice A and Bianchini, Claudia and Bird, Lynne M and Buchert, Rebecca and Carr{\'e}, Wilfrid and Ceulemans, Sophia and Charles, Perrine and Cox, Helen and Culliton, Lisa and Curr{\`o}, Aurora and Demurger, Florence and Dowling, James J and Duban-Bedu, Benedicte and Dubourg, Christ{\`e}le and Eiset, Saga Elise and Escobar, Luis F and Ferrarini, Alessandra and Haack, Tobias B and Hashim, Mona and Heide, Solveig and Helbig, Katherine L and Helbig, Ingo and Heredia, Raul and H{\'e}ron, Delphine and Isidor, Bertrand and Jonasson, Amy R and Joset, Pascal and Keren, Boris and Kok, Fernando and Kroes, Hester Y and Lavillaureix, Alino{\"e} and Lu, Xin and Maas, Saskia M and Maegawa, Gustavo H B and Marcelis, Carlo L M and Mark, Paul R and Masruha, Marcelo R and McLaughlin, Heather M and McWalter, Kirsty and Melchinger, Esther U and Mercimek-Andrews, Saadet and Nava, Caroline and Pendziwiat, Manuela and Person, Richard and Ramelli, Gian Paolo and Ramos, Luiza L P and Rauch, Anita and Reavey, Caitlin and Renieri, Alessandra and Rie{\ss}, Angelika and Sanchez-Valle, Amarilis and Sattar, Shifteh and Saunders, Carol and Schwarz, Niklas and Smol, Thomas and Srour, Myriam and Steindl, Katharina and Syrbe, Steffen and Taylor, Jenny C and Telegrafi, Aida and Thiffault, Isabelle and Trauner, Doris A and van der Linden, Helio and van Koningsbruggen, Silvana and Villard, Laurent and Vogel, Ida and Vogt, Julie and Weber, Yvonne G and Wentzensen, Ingrid M and Widjaja, Elysa and Zak, Jaroslav and Baxter, Samantha and Banka, Siddharth and Rodan, Lance H} }