@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 = {<p>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).</p>},
	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 = {<p>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.</p>},
	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}
}
