@article {670, title = {CTCF variants in 39 individuals with a variable neurodevelopmental disorder broaden the mutational and clinical spectrum.}, journal = {Genet Med}, volume = {21}, year = {2019}, month = {2019 12}, pages = {2723-2733}, abstract = {

PURPOSE: Pathogenic variants in the chromatin organizer CTCF were previously reported in seven individuals with a neurodevelopmental disorder (NDD).

METHODS: Through international collaboration we collected data from 39 subjects with variants in CTCF. We performed transcriptome analysis on RNA from blood samples and utilized Drosophila melanogaster to investigate the impact of Ctcf dosage alteration on nervous system development and function.

RESULTS: The individuals in our cohort carried 2 deletions, 8 likely gene-disruptive, 2 splice-site, and 20 different missense variants, most of them de novo. Two cases were familial. The associated phenotype was of variable severity extending from mild developmental delay or normal IQ to severe intellectual disability. Feeding difficulties and behavioral abnormalities were common, and variable other findings including growth restriction and cardiac defects were observed. RNA-sequencing in five individuals identified 3828 deregulated genes enriched for known NDD genes and biological processes such as transcriptional regulation. Ctcf dosage alteration in Drosophila resulted in impaired gross neurological functioning and learning and memory deficits.

CONCLUSION: We significantly broaden the mutational and clinical spectrum ofCTCF-associated NDDs. Our data shed light onto the functional role of CTCF by identifying deregulated genes and show that Ctcf alterations result in nervous system defects in Drosophila.

}, issn = {1530-0366}, doi = {10.1038/s41436-019-0585-z}, author = {Konrad, Enrico D H and Nardini, Niels and Caliebe, Almuth and Nagel, Inga and Young, Dana and Horvath, Gabriella and Santoro, Stephanie L and Shuss, Christine and Ziegler, Alban and Bonneau, Dominique and Kempers, Marlies and Pfundt, Rolph and Legius, Eric and Bouman, Arjan and Stuurman, Kyra E and {\~O}unap, Katrin and Pajusalu, Sander and Wojcik, Monica H and Vasileiou, Georgia and Le Guyader, Gwena{\"e}l and Schnelle, Hege M and Berland, Siren and Zonneveld-Huijssoon, Evelien and Kersten, Simone and Gupta, Aditi and Blackburn, Patrick R and Ellingson, Marissa S and Ferber, Matthew J and Dhamija, Radhika and Klee, Eric W and McEntagart, Meriel and Lichtenbelt, Klaske D and Kenney, Amy and Vergano, Samantha A and Abou Jamra, Rami and Platzer, Konrad and Ella Pierpont, Mary and Khattar, Divya and Hopkin, Robert J and Martin, Richard J and Jongmans, Marjolijn C J and Chang, Vivian Y and Martinez-Agosto, Julian A and Kuismin, Outi and Kurki, Mitja I and Pietil{\"a}inen, Olli and Palotie, Aarno and Maarup, Timothy J and Johnson, Diana S and Venborg Pedersen, Katja and Laulund, Lone W and Lynch, Sally A and Blyth, Moira and Prescott, Katrina and Canham, Natalie and Ibitoye, Rita and Brilstra, Eva H and Shinawi, Marwan and Fassi, Emily and Sticht, Heinrich and Gregor, Anne and Van Esch, Hilde and Zweier, Christiane} } @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 {719, title = {Loss of SMPD4 Causes a Developmental Disorder Characterized by Microcephaly and Congenital Arthrogryposis.}, journal = {Am J Hum Genet}, volume = {105}, year = {2019}, month = {2019 Oct 03}, pages = {689-705}, abstract = {

Sphingomyelinases generate ceramide from sphingomyelin as a second messenger in intracellular signaling pathways involved in cell proliferation, differentiation, or apoptosis. Children from 12 unrelated families presented with microcephaly, simplified gyral pattern of the cortex, hypomyelination, cerebellar hypoplasia, congenital arthrogryposis, and early fetal/postnatal demise. Genomic analysis revealed bi-allelic loss-of-function variants in SMPD4, coding for the neutral sphingomyelinase-3 (nSMase-3/SMPD4). Overexpression of human Myc-tagged SMPD4 showed localization both to the outer nuclear envelope and the ER and additionally revealed interactions with several nuclear pore complex proteins by proteomics analysis. Fibroblasts from affected individuals showed ER cisternae abnormalities, suspected for increased autophagy, and were more susceptible to apoptosis under stress conditions, while treatment with siSMPD4 caused delayed cell cycle progression. Our data show that SMPD4 links homeostasis of membrane sphingolipids to cell fate by regulating the cross-talk between the ER and the outer nuclear envelope, while its loss reveals a pathogenic mechanism in microcephaly.

}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2019.08.006}, author = {Magini, Pamela and Smits, Daphne J and Vandervore, Laura and Schot, Rachel and Columbaro, Marta and Kasteleijn, Esmee and van der Ent, Mees and Palombo, Flavia and Lequin, Maarten H and Dremmen, Marjolein and de Wit, Marie Claire Y and Severino, Mariasavina and Divizia, Maria Teresa and Striano, Pasquale and Ordonez-Herrera, Natalia and Alhashem, Amal and Al Fares, Ahmed and Al Ghamdi, Malak and Rolfs, Arndt and Bauer, Peter and Demmers, Jeroen and Verheijen, Frans W and Wilke, Martina and van Slegtenhorst, Marjon and van der Spek, Peter J and Seri, Marco and Jansen, Anna C and Stottmann, Rolf W and Hufnagel, Robert B and Hopkin, Robert J and Aljeaid, Deema and Wiszniewski, Wojciech and Gawlinski, Pawel and Laure-Kamionowska, Milena and Alkuraya, Fowzan S and Akleh, Hanah and Stanley, Valentina and Musaev, Damir and Gleeson, Joseph G and Zaki, Maha S and Brunetti-Pierri, Nicola and Cappuccio, Gerarda and Davidov, Bella and Basel-Salmon, Lina and Bazak, Lily and Shahar, Noa Ruhrman and Bertoli-Avella, Aida and Mirzaa, Ghayda M and Dobyns, William B and Pippucci, Tommaso and Fornerod, Maarten and Mancini, Grazia M S} } @article {597, title = {Novel parent-of-origin-specific differentially methylated loci on chromosome 16.}, journal = {Clin Epigenetics}, volume = {11}, year = {2019}, month = {2019 04 08}, pages = {60}, abstract = {

BACKGROUND: Congenital malformations associated with maternal uniparental disomy of chromosome 16, upd(16)mat, resemble those observed in newborns with the lethal developmental lung disease, alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV). Interestingly, ACDMPV-causative deletions, involving FOXF1 or its lung-specific upstream enhancer at 16q24.1, arise almost exclusively on the maternally inherited chromosome 16. Given the phenotypic similarities between upd(16)mat and ACDMPV, together with parental allelic bias in ACDMPV, we hypothesized that there may be unknown imprinted loci mapping to chromosome 16 that become functionally unmasked by chromosomal structural variants.

RESULTS: To identify parent-of-origin biased DNA methylation, we performed high-resolution bisulfite sequencing of chromosome 16 on peripheral blood and cultured skin fibroblasts from individuals with maternal or paternal upd(16) as well as lung tissue from patients with ACDMPV-causative 16q24.1 deletions and a normal control. We identified 22 differentially methylated regions (DMRs) with >= 5 consecutive CpG methylation sites and varying tissue-specificity, including the known DMRs associated with the established imprinted gene ZNF597 and DMRs supporting maternal methylation of PRR25, thought to be paternally expressed in lymphoblastoid cells. Lastly, we found evidence of paternal methylation on 16q24.1 near LINC01082 mapping to the FOXF1 enhancer.

CONCLUSIONS: Using high-resolution bisulfite sequencing to evaluate DNA methylation across chromosome 16, we found evidence for novel candidate imprinted loci on chromosome 16 that would not be evident in array-based assays and could contribute to the birth defects observed in patients with upd(16)mat or in ACDMPV.

}, issn = {1868-7083}, doi = {10.1186/s13148-019-0655-8}, author = {Schulze, Katharina V and Szafranski, Przemyslaw and Lesmana, Harry and Hopkin, Robert J and Hamvas, Aaron and Wambach, Jennifer A and Shinawi, Marwan and Zapata, Gladys and Carvalho, Claudia M B and Liu, Qian and Karolak, Justyna A and Lupski, James R and Hanchard, Neil A and Stankiewicz, Pawe{\l}} } @article {685, title = {Redefining the Etiologic Landscape of Cerebellar Malformations.}, journal = {Am J Hum Genet}, volume = {105}, year = {2019}, month = {2019 Sep 05}, pages = {606-615}, abstract = {

Cerebellar malformations are diverse congenital anomalies frequently associated with developmental disability. Although genetic and prenatal non-genetic causes have been described, no systematic analysis has been performed. Here, we present a large-exome sequencing study of Dandy-Walker malformation (DWM) and cerebellar hypoplasia (CBLH). We performed exome sequencing in 282 individuals from 100 families with DWM or CBLH, and we established a molecular diagnosis in 36 of 100 families, with a significantly higher yield for CBLH (51\%) than for DWM (16\%). The 41 variants impact 27 neurodevelopmental-disorder-associated genes, thus demonstrating that CBLH and DWM are often features of monogenic neurodevelopmental disorders. Though only seven monogenic causes (19\%) were identified in more than one individual, neuroimaging review of 131 additional individuals confirmed cerebellar abnormalities in 23 of 27 genetic disorders (85\%). Prenatal risk factors were frequently found among individuals without a genetic diagnosis (30 of 64 individuals [47\%]). Single-cell RNA sequencing of prenatal human cerebellar tissue revealed gene enrichment in neuronal and vascular cell types; this suggests that defective vasculogenesis may disrupt cerebellar development. Further, de novo gain-of-function variants in PDGFRB, a tyrosine kinase receptor essential for vascular progenitor signaling, were associated with CBLH, and this discovery links genetic and non-genetic etiologies. Our results suggest that genetic defects impact specific cerebellar cell types and implicate abnormal vascular development as a mechanism for cerebellar malformations. We also confirmed a major contribution for non-genetic prenatal factors in individuals with cerebellar abnormalities, substantially influencing diagnostic evaluation and counseling regarding recurrence risk and prognosis.

}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2019.07.019}, author = {Aldinger, Kimberly A and Timms, Andrew E and Thomson, Zachary and Mirzaa, Ghayda M and Bennett, James T and Rosenberg, Alexander B and Roco, Charles M and Hirano, Matthew and Abidi, Fatima and Haldipur, Parthiv and Cheng, Chi V and Collins, Sarah and Park, Kaylee and Zeiger, Jordan and Overmann, Lynne M and Alkuraya, Fowzan S and Biesecker, Leslie G and Braddock, Stephen R and Cathey, Sara and Cho, Megan T and Chung, Brian H Y and Everman, David B and Zarate, Yuri A and Jones, Julie R and Schwartz, Charles E and Goldstein, Amy and Hopkin, Robert J and Krantz, Ian D and Ladda, Roger L and Leppig, Kathleen A and McGillivray, Barbara C and Sell, Susan and Wusik, Katherine and Gleeson, Joseph G and Nickerson, Deborah A and Bamshad, Michael J and Gerrelli, Dianne and Lisgo, Steven N and Seelig, Georg and Ishak, Gisele E and Barkovich, A James and Curry, Cynthia J and Glass, Ian A and Millen, Kathleen J and Doherty, Dan and Dobyns, William B} } @article {251, title = {Clinical utility of whole-exome sequencing in rare diseases: Galactosialidosis.}, journal = {Eur J Med Genet}, volume = {57}, year = {2014}, month = {2014 Jul}, pages = {339-344}, abstract = {

Rare genetic disorders can go undiagnosed for years as the entire spectrum of phenotypic variation is not well characterized given the reduced number of patients reported in the literature and the low frequency at which these occur. Moreover, the current paradigm for clinical diagnostics defines disease diagnosis by a specified spectrum of phenotypic findings; when such parameters are either missing, or other findings not usually observed are seen, the phenotype driven approach to diagnosis may result in a specific etiological diagnosis not even being considered within the differential diagnosis. The novel implementation of genomic sequencing approaches to investigate rare genetic disorders is allowing not only the discovery of new genes, but also the phenotypic expansion of known Mendelian genetic disorders. Here we report the detailed clinical assessment of a patient with a rare genetic disorder with undefined molecular diagnosis. We applied whole-exome sequencing to this patient and unaffected parents in order to identify the molecular cause of her disorder. We identified compound heterozygous mutations in the CTSA gene, responsible for causing galactosialidosis; the molecular diagnosis was further confirmed by biochemical studies. This report expands on the clinical spectrum of this rare lysosomal disorder and exemplifies how genomic approaches are further elucidating the characterization and understanding of genetic diseases.

}, keywords = {Adult, Cathepsin A, Exome, Female, Humans, Lysosomal Storage Diseases, Mutation, Rare Diseases, Sequence Analysis, DNA, Young Adult}, issn = {1878-0849}, doi = {10.1016/j.ejmg.2014.04.005}, author = {Prada, Carlos E and Gonzaga-Jauregui, Claudia and Tannenbaum, Rebecca and Penney, Samantha and Lupski, James R and Hopkin, Robert J and Sutton, V Reid} }