@article {940, title = {Polymicrogyria is Associated With Pathogenic Variants in PTEN.}, journal = {Ann Neurol}, volume = {88}, year = {2020}, month = {2020 12}, pages = {1153-1164}, abstract = {

OBJECTIVE: Congenital structural brain malformations have been described in patients with pathogenic phosphatase and tensin homologue (PTEN) variants, but the frequency of cortical malformations in patients with PTEN variants and their impact on clinical phenotype are not well understood. Our goal was to systematically characterize brain malformations in patients with PTEN variants and assess the relevance of their brain malformations to clinical presentation.

METHODS: We systematically searched a local radiology database for patients with PTEN variants who had available brain magnetic resonance imaging (MRI). The MRI scans were reviewed systematically for cortical abnormalities. We reviewed electroencephalogram (EEG) data and evaluated the electronic medical record for evidence of epilepsy and developmental delay.

RESULTS: In total, we identified 22 patients with PTEN pathogenic variants for which brain MRIs were available (age range 0.4-17 years). Twelve among these 22 patients (54\%) had polymicrogyria (PMG). Variants associated with PMG or atypical gyration encoded regions of the phosphatase or C2 domains of PTEN. Interestingly, epilepsy was present in only 2 of the 12 patients with PMG. We found a trend toward higher rates of global developmental delay (GDD), intellectual disability (ID), and motor delay in individuals with cortical abnormalities, although cohort size limited statistical significance.

INTERPRETATION: Malformations of cortical development, PMG in particular, represent an under-recognized phenotype associated with PTEN pathogenic variants and may have an association with cognitive and motor delays. Epilepsy was infrequent compared to the previously reported high risk of epilepsy in patients with PMG. ANN NEUROL 2020;88:1153-1164.

}, keywords = {Adolescent, Brain, Child, Child, Preschool, Comorbidity, Databases, Genetic, Developmental Disabilities, Electroencephalography, Female, Humans, Infant, Intellectual Disability, Magnetic Resonance Imaging, Male, Massachusetts, Neuroimaging, Polymicrogyria, PTEN Phosphohydrolase}, issn = {1531-8249}, doi = {10.1002/ana.25904}, author = {Shao, Diane D and Achkar, Christelle M and Lai, Abbe and Srivastava, Siddharth and Doan, Ryan N and Rodan, Lance H and Chen, Allen Y and Poduri, Annapurna and Yang, Edward and Walsh, Christopher A} } @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 {677, title = {Bi-allelic Variants in DYNC1I2 Cause Syndromic Microcephaly with Intellectual Disability, Cerebral Malformations, and Dysmorphic Facial Features.}, journal = {Am J Hum Genet}, volume = {104}, year = {2019}, month = {2019 Jun 06}, pages = {1073-1087}, abstract = {

Cargo transport along the cytoplasmic microtubular network is essential for neuronal function, and cytoplasmic dynein-1 is an established molecular motor that is critical for neurogenesis and homeostasis. We performed whole-exome sequencing, homozygosity mapping, and chromosomal microarray studies in five individuals from three independent pedigrees and identified likely-pathogenic variants in DYNC1I2 (Dynein Cytoplasmic 1 Intermediate Chain 2), encoding a component of the cytoplasmic dynein 1 complex. In a consanguineous Pakistani family with three affected individuals presenting with microcephaly, severe intellectual disability, simplification of cerebral gyration, corpus callosum hypoplasia, and dysmorphic facial features, we identified a homozygous splice donor site variant (GenBank: NM_001378.2:c.607+1G>A). We report two additional individuals who have similar neurodevelopmental deficits and craniofacial features and harbor deleterious variants; one individual bears a c.740A>G (p.Tyr247Cys) change in trans with a 374~kb deletion encompassing DYNC1I2, and an unrelated individual harbors the compound-heterozygous variants c.868C>T (p.Gln290) and c.740A>G (p.Tyr247Cys). Zebrafish larvae subjected to CRISPR-Cas9 gene disruption or transient suppression of dync1i2a displayed significantly altered craniofacial patterning with concomitant reduction in head size. We monitored cell death and cell cycle progression in dync1i2a zebrafish models and observed significantly increased apoptosis, likely due to prolonged mitosis caused by abnormal spindle morphology, and this finding offers initial insights into the cellular basis of microcephaly. Additionally, complementation studies in zebrafish demonstrate that p.Tyr247Cys attenuates gene function, consistent with protein structural analysis. Our genetic and functional data indicate that DYNC1I2 dysfunction probably causes an autosomal-recessive microcephaly syndrome and highlight further the critical roles of the dynein-1 complex in neurodevelopment.

}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2019.04.002}, author = {Ansar, Muhammad and Ullah, Farid and Paracha, Sohail A and Adams, Darius J and Lai, Abbe and Pais, Lynn and Iwaszkiewicz, Justyna and Millan, Francisca and Sarwar, Muhammad T and Agha, Zehra and Shah, Sayyed Fahim and Qaisar, Azhar Ali and Falconnet, Emilie and Zoete, Vincent and Ranza, Emmanuelle and Makrythanasis, Periklis and Santoni, Federico A and Ahmed, Jawad and Katsanis, Nicholas and Walsh, Christopher and Davis, Erica E and Antonarakis, Stylianos E} }