@article {930, title = {Posterior Neocortex-Specific Regulation of Neuronal Migration by CEP85L Identifies Maternal Centriole-Dependent Activation of CDK5.}, journal = {Neuron}, volume = {106}, year = {2020}, month = {2020 04 22}, pages = {246-255.e6}, abstract = {

Genes mutated in human neuronal migration disorders encode tubulin proteins and a variety of tubulin-binding and -regulating proteins, but it is very poorly understood how these proteins function together to coordinate migration. Additionally, the way in which regional differences in neocortical migration are controlled is completely unknown. Here we describe a new syndrome with remarkably region-specific effects on neuronal migration in the posterior cortex, reflecting de novo variants in CEP85L. We show that CEP85L is required cell autonomously in~vivo and in~vitro for migration, that it localizes to the maternal centriole, and that it forms a complex with many other proteins required for migration, including CDK5, LIS1, NDE1, KIF2A, and DYNC1H1. Loss of CEP85L disrupts CDK5 localization and activation, leading to centrosome disorganization and disrupted microtubule cytoskeleton organization. Together, our findings suggest that CEP85L highlights a complex that controls CDK5 activity to promote neuronal migration.

}, keywords = {Cell Movement, Centrioles, Child, Child, Preschool, Cyclin-Dependent Kinase 5, Cytoskeletal Proteins, Female, Humans, Lissencephaly, Male, Microtubules, Neocortex, Nerve Tissue Proteins, Neurons, Oncogene Proteins, Fusion, Young Adult}, issn = {1097-4199}, doi = {10.1016/j.neuron.2020.01.030}, author = {Kodani, Andrew and Kenny, Connor and Lai, Abbe and Gonzalez, Dilenny M and Stronge, Edward and Sejourne, Gabrielle M and Isacco, Laura and Partlow, Jennifer N and O{\textquoteright}Donnell, Anne and McWalter, Kirsty and Byrne, Alicia B and Barkovich, A James and Yang, Edward and Hill, R Sean and Gawlinski, Pawel and Wiszniewski, Wojciech and Cohen, Julie S and Fatemi, S Ali and Baranano, Kristin W and Sahin, Mustafa and Vossler, David G and Yuskaitis, Christopher J and Walsh, Christopher A} } @article {746, title = {Regulation of human cerebral cortical development by EXOC7 and EXOC8, components of the exocyst complex, and roles in neural progenitor cell proliferation and survival.}, journal = {Genet Med}, volume = {22}, year = {2020}, month = {2020 06}, pages = {1040-1050}, abstract = {

PURPOSE: The exocyst complex is a conserved protein complex that mediates fusion of intracellular vesicles to the plasma membrane and is implicated in processes including cell polarity, cell migration, ciliogenesis, cytokinesis, autophagy, and fusion of secretory vesicles. The essential role of these genes in human genetic disorders, however, is unknown.

METHODS: We performed homozygosity mapping and exome sequencing of consanguineous families with recessively inherited brain development disorders. We modeled an EXOC7 splice variant in vitro and examined EXOC7 messenger RNA (mRNA) expression in developing mouse and human cortex. We modeled exoc7 loss-of-function in a zebrafish knockout.

RESULTS: We report variants in exocyst complex members, EXOC7 and EXOC8, in a novel disorder of cerebral cortex development. In EXOC7, we identified four independent partial loss-of-function (LOF) variants in a recessively inherited disorder characterized by brain atrophy, seizures, and developmental delay, and in severe cases, microcephaly and infantile death. In EXOC8, we found a homozygous truncating variant in a family with a similar clinical disorder. We modeled exoc7 deficiency in zebrafish and found the absence of exoc7 causes microcephaly.

CONCLUSION: Our results highlight the essential role of the exocyst pathway in normal cortical development and how its perturbation causes complex brain disorders.

}, keywords = {Animals, Brain Diseases, Cell Proliferation, Homozygote, Humans, Mice, Microcephaly, Zebrafish}, issn = {1530-0366}, doi = {10.1038/s41436-020-0758-9}, author = {Coulter, Michael E and Musaev, Damir and DeGennaro, Ellen M and Zhang, Xiaochang and Henke, Katrin and James, Kiely N and Smith, Richard S and Hill, R Sean and Partlow, Jennifer N and Kamumbu, A Stacy and Hatem, Nicole and Barkovich, A James and Aziza, Jacqueline and Chassaing, Nicolas and Zaki, MAH S and Sultan, Tipu and Burglen, Lydie and Rajab, Anna and Al-Gazali, Lihadh and Mochida, Ganeshwaran H and Harris, Matthew P and Gleeson, Joseph G and Walsh, Christopher A} } @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 {148, title = {An siRNA-based functional genomics screen for the~identification of regulators of ciliogenesis and ciliopathy~genes.}, journal = {Nat Cell Biol}, volume = {17}, year = {2015}, month = {2015 Aug}, pages = {1074-1087}, abstract = {

Defects in primary cilium biogenesis underlie the ciliopathies, a growing group of genetic disorders. We describe a whole-genome siRNA-based reverse genetics screen for defects in biogenesis and/or maintenance of the primary cilium, obtaining a global resource. We identify 112 candidate ciliogenesis and ciliopathy genes, including 44 components of the ubiquitin-proteasome system, 12 G-protein-coupled receptors, and 3 pre-mRNA processing factors (PRPF6, PRPF8 and PRPF31) mutated in autosomal dominant retinitis pigmentosa. The PRPFs localize to the connecting cilium, and PRPF8- and PRPF31-mutated cells have ciliary defects. Combining the screen with exome sequencing data identified recessive mutations in PIBF1, also known as CEP90, and C21orf2, also known as LRRC76, as causes of the ciliopathies Joubert and Jeune syndromes. Biochemical approaches place C21orf2 within key ciliopathy-associated protein modules, offering an explanation for the skeletal and retinal involvement observed in individuals with C21orf2 variants. Our global, unbiased approaches provide insights into ciliogenesis complexity and identify roles for unanticipated pathways in human genetic disease.

}, keywords = {Abnormalities, Multiple, Animals, Caenorhabditis elegans, Cerebellar Diseases, Cerebellum, Cilia, Ciliary Motility Disorders, Databases, Genetic, Ellis-Van Creveld Syndrome, Eye Abnormalities, Genetic Markers, Genetic Predisposition to Disease, Genetic Testing, Genome-Wide Association Study, Genomics, HEK293 Cells, High-Throughput Nucleotide Sequencing, Humans, Kidney Diseases, Cystic, Membrane Proteins, Mice, Inbred C57BL, Mice, Knockout, Mutation, Phenotype, Photoreceptor Cells, Pregnancy Proteins, Proteins, Reproducibility of Results, Retina, RNA Interference, Suppressor Factors, Immunologic, Transfection, Zebrafish}, issn = {1476-4679}, doi = {10.1038/ncb3201}, author = {Wheway, Gabrielle and Schmidts, Miriam and Mans, Dorus A and Szymanska, Katarzyna and Nguyen, Thanh-Minh T and Racher, Hilary and Phelps, Ian G and Toedt, Grischa and Kennedy, Julie and Wunderlich, Kirsten A and Sorusch, Nasrin and Abdelhamed, Zakia A and Natarajan, Subaashini and Herridge, Warren and van Reeuwijk, Jeroen and Horn, Nicola and Boldt, Karsten and Parry, David A and Letteboer, Stef J F and Roosing, Susanne and Adams, Matthew and Bell, Sandra M and Bond, Jacquelyn and Higgins, Julie and Morrison, Ewan E and Tomlinson, Darren C and Slaats, Gisela G and van Dam, Teunis J P and Huang, Lijia and Kessler, Kristin and Giessl, Andreas and Logan, Clare V and Boyle, Evan A and Shendure, Jay and Anazi, Shamsa and Aldahmesh, Mohammed and Al Hazzaa, Selwa and Hegele, Robert A and Ober, Carole and Frosk, Patrick and Mhanni, Aizeddin A and Chodirker, Bernard N and Chudley, Albert E and Lamont, Ryan and Bernier, Francois P and Beaulieu, Chandree L and Gordon, Paul and Pon, Richard T and Donahue, Clem and Barkovich, A James and Wolf, Louis and Toomes, Carmel and Thiel, Christian T and Boycott, Kym M and McKibbin, Martin and Inglehearn, Chris F and Stewart, Fiona and Omran, Heymut and Huynen, Martijn A and Sergouniotis, Panagiotis I and Alkuraya, Fowzan S and Parboosingh, Jillian S and Innes, A Micheil and Willoughby, Colin E and Giles, Rachel H and Webster, Andrew R and Ueffing, Marius and Blacque, Oliver and Gleeson, Joseph G and Wolfrum, Uwe and Beales, Philip L and Gibson, Toby and Doherty, Dan and Mitchison, Hannah M and Roepman, Ronald and Johnson, Colin A} } @article {226, title = {Somatic mutations in cerebral cortical malformations.}, journal = {N Engl J Med}, volume = {371}, year = {2014}, month = {2014 Aug 21}, pages = {733-43}, abstract = {

BACKGROUND: Although there is increasing recognition of the role of somatic mutations in genetic disorders, the prevalence of somatic mutations in neurodevelopmental disease and the optimal techniques to detect somatic mosaicism have not been systematically evaluated.

METHODS: Using a customized panel of known and candidate genes associated with brain malformations, we applied targeted high-coverage sequencing (depth, >=200{\texttimes}) to leukocyte-derived DNA samples from 158 persons with brain malformations, including the double-cortex syndrome (subcortical band heterotopia, 30 persons), polymicrogyria with megalencephaly (20), periventricular nodular heterotopia (61), and pachygyria (47). We validated candidate mutations with the use of Sanger sequencing and, for variants present at unequal read depths, subcloning followed by colony sequencing.

RESULTS: Validated, causal mutations were found in 27 persons (17\%; range, 10 to 30\% for each phenotype). Mutations were somatic in 8 of the 27 (30\%), predominantly in persons with the double-cortex syndrome (in whom we found mutations in DCX and LIS1), persons with periventricular nodular heterotopia (FLNA), and persons with pachygyria (TUBB2B). Of the somatic mutations we detected, 5 (63\%) were undetectable with the use of traditional Sanger sequencing but were validated through subcloning and subsequent sequencing of the subcloned DNA. We found potentially causal mutations in the candidate genes DYNC1H1, KIF5C, and other kinesin genes in persons with pachygyria.

CONCLUSIONS: Targeted sequencing was found to be useful for detecting somatic mutations in patients with brain malformations. High-coverage sequencing panels provide an important complement to whole-exome and whole-genome sequencing in the evaluation of somatic mutations in neuropsychiatric disease. (Funded by the National Institute of Neurological Disorders and Stroke and others.).

}, keywords = {Cerebral Cortex, Classical Lissencephalies and Subcortical Band Heterotopias, DNA Mutational Analysis, Humans, Lissencephaly, Magnetic Resonance Imaging, Malformations of Cortical Development, Mutation, Periventricular Nodular Heterotopia}, issn = {1533-4406}, doi = {10.1056/NEJMoa1314432}, author = {Jamuar, Saumya S and Lam, Anh-Thu N and Kircher, Martin and D{\textquoteright}Gama, Alissa M and Wang, Jian and Barry, Brenda J and Zhang, Xiaochang and Hill, Robert Sean and Partlow, Jennifer N and Rozzo, Aldo and Servattalab, Sarah and Mehta, Bhaven K and Topcu, Meral and Amrom, Dina and Andermann, Eva and Dan, Bernard and Parrini, Elena and Guerrini, Renzo and Scheffer, Ingrid E and Berkovic, Samuel F and Leventer, Richard J and Shen, Yiping and Wu, Bai Lin and Barkovich, A James and Sahin, Mustafa and Chang, Bernard S and Bamshad, Michael and Nickerson, Deborah A and Shendure, Jay and Poduri, Annapurna and Yu, Timothy W and Walsh, Christopher A} }