101
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Biallelic mutations in human DCC cause developmental split-brain syndrome. Nat Genet 2017; 49:606-612. [PMID: 28250456 PMCID: PMC5374027 DOI: 10.1038/ng.3804] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 02/03/2017] [Indexed: 12/14/2022]
Abstract
Motor, sensory, and integrative activities of the brain are coordinated by a series of midline-bridging neuronal commissures whose development is tightly regulated. Here we report a new human syndrome in which these commissures are widely disrupted, thus causing clinical manifestations of horizontal gaze palsy, scoliosis, and intellectual disability. Affected individuals were found to possess biallelic loss-of-function mutations in the gene encoding the axon-guidance receptor 'deleted in colorectal carcinoma' (DCC), which has been implicated in congenital mirror movements when it is mutated in the heterozygous state but whose biallelic loss-of-function human phenotype has not been reported. Structural MRI and diffusion tractography demonstrated broad disorganization of white-matter tracts throughout the human central nervous system (CNS), including loss of all commissural tracts at multiple levels of the neuraxis. Combined with data from animal models, these findings show that DCC is a master regulator of midline crossing and development of white-matter projections throughout the human CNS.
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102
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Macia MS, Halbritter J, Delous M, Bredrup C, Gutter A, Filhol E, Mellgren AE, Leh S, Bizet A, Braun DA, Gee HY, Silbermann F, Henry C, Krug P, Bole-Feysot C, Nitschké P, Joly D, Nicoud P, Paget A, Haugland H, Brackmann D, Ahmet N, Sandford R, Cengiz N, Knappskog PM, Boman H, Linghu B, Yang F, Oakeley EJ, Saint Mézard P, Sailer AW, Johansson S, Rødahl E, Saunier S, Hildebrandt F, Benmerah A. Mutations in MAPKBP1 Cause Juvenile or Late-Onset Cilia-Independent Nephronophthisis. Am J Hum Genet 2017; 100:323-333. [PMID: 28089251 DOI: 10.1016/j.ajhg.2016.12.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 12/08/2016] [Indexed: 11/26/2022] Open
Abstract
Nephronophthisis (NPH), an autosomal-recessive tubulointerstitial nephritis, is the most common cause of hereditary end-stage renal disease in the first three decades of life. Since most NPH gene products (NPHP) function at the primary cilium, NPH is classified as a ciliopathy. We identified mutations in a candidate gene in eight individuals from five families presenting late-onset NPH with massive renal fibrosis. This gene encodes MAPKBP1, a poorly characterized scaffolding protein for JNK signaling. Immunofluorescence analyses showed that MAPKBP1 is not present at the primary cilium and that fibroblasts from affected individuals did not display ciliogenesis defects, indicating that MAPKBP1 may represent a new family of NPHP not involved in cilia-associated functions. Instead, MAPKBP1 is recruited to mitotic spindle poles (MSPs) during the early phases of mitosis where it colocalizes with its paralog WDR62, which plays a key role at MSP. Detected mutations compromise recruitment of MAPKBP1 to the MSP and/or its interaction with JNK2 or WDR62. Additionally, we show increased DNA damage response signaling in fibroblasts from affected individuals and upon knockdown of Mapkbp1 in murine cell lines, a phenotype previously associated with NPH. In conclusion, we identified mutations in MAPKBP1 as a genetic cause of juvenile or late-onset and cilia-independent NPH.
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103
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Lee J. Malformations of cortical development: genetic mechanisms and diagnostic approach. KOREAN JOURNAL OF PEDIATRICS 2017; 60:1-9. [PMID: 28203254 PMCID: PMC5309318 DOI: 10.3345/kjp.2017.60.1.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 11/20/2015] [Accepted: 12/16/2015] [Indexed: 01/09/2023]
Abstract
Malformations of cortical development are rare congenital anomalies of the cerebral cortex, wherein patients present with intractable epilepsy and various degrees of developmental delay. Cases show a spectrum of anomalous cortical formations with diverse anatomic and morphological abnormalities, a variety of genetic causes, and different clinical presentations. Brain magnetic resonance imaging has been of great help in determining the exact morphologies of cortical malformations. The hypothetical mechanisms of malformation include interruptions during the formation of cerebral cortex in the form of viral infection, genetic causes, and vascular events. Recent remarkable developments in genetic analysis methods have improved our understanding of these pathological mechanisms. The present review will discuss normal cortical development, the current proposed malformation classifications, and the diagnostic approach for malformations of cortical development.
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Affiliation(s)
- Jeehun Lee
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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104
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Jiang C, Gai N, Zou Y, Zheng Y, Ma R, Wei X, Liang D, Wu L. WDR73 missense mutation causes infantile onset intellectual disability and cerebellar hypoplasia in a consanguineous family. Clin Chim Acta 2017; 464:24-29. [DOI: 10.1016/j.cca.2016.10.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 10/26/2016] [Accepted: 10/26/2016] [Indexed: 12/22/2022]
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105
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Lim NR, Yeap YYC, Ang CS, Williamson NA, Bogoyevitch MA, Quinn LM, Ng DCH. Aurora A phosphorylation of WD40-repeat protein 62 in mitotic spindle regulation. Cell Cycle 2016; 15:413-24. [PMID: 26713495 DOI: 10.1080/15384101.2015.1127472] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Mitotic spindle organization is regulated by centrosomal kinases that potentiate recruitment of spindle-associated proteins required for normal mitotic progress including the microcephaly protein WD40-repeat protein 62 (WDR62). WDR62 functions underlie normal brain development as autosomal recessive mutations and wdr62 loss cause microcephaly. Here we investigate the signaling interactions between WDR62 and the mitotic kinase Aurora A (AURKA) that has been recently shown to cooperate to control brain size in mice. The spindle recruitment of WDR62 is closely correlated with increased levels of AURKA following mitotic entry. We showed that depletion of TPX2 attenuated WDR62 localization at spindle poles indicating that TPX2 co-activation of AURKA is required to recruit WDR62 to the spindle. We demonstrated that AURKA activity contributed to the mitotic phosphorylation of WDR62 residues Ser49 and Thr50 and phosphorylation of WDR62 N-terminal residues was required for spindle organization and metaphase chromosome alignment. Our analysis of several MCPH-associated WDR62 mutants (V65M, R438H and V1314RfsX18) that are mislocalized in mitosis revealed that their interactions and phosphorylation by AURKA was substantially reduced consistent with the notion that AURKA is a key determinant of WDR62 spindle recruitment. Thus, our study highlights the role of AURKA signaling in the spatiotemporal control of WDR62 at spindle poles where it maintains spindle organization.
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Affiliation(s)
- Nicholas R Lim
- a Department of Biochemistry and Molecular Biology , University of Melbourne , Victoria , Australia.,b Bio21 Molecular Science and Biotechnology Institute, University of Melbourne , Victoria , Australia
| | - Yvonne Y C Yeap
- a Department of Biochemistry and Molecular Biology , University of Melbourne , Victoria , Australia.,d School of Biomedical Sciences, University of Queensland , St Lucia , Australia
| | - Ching-Seng Ang
- b Bio21 Molecular Science and Biotechnology Institute, University of Melbourne , Victoria , Australia
| | - Nicholas A Williamson
- b Bio21 Molecular Science and Biotechnology Institute, University of Melbourne , Victoria , Australia
| | - Marie A Bogoyevitch
- a Department of Biochemistry and Molecular Biology , University of Melbourne , Victoria , Australia.,b Bio21 Molecular Science and Biotechnology Institute, University of Melbourne , Victoria , Australia
| | - Leonie M Quinn
- c Department of Anatomy and Neuroscience , University of Melbourne , Victoria , Australia
| | - Dominic C H Ng
- a Department of Biochemistry and Molecular Biology , University of Melbourne , Victoria , Australia.,d School of Biomedical Sciences, University of Queensland , St Lucia , Australia
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106
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Wang J, Lin ZJ, Liu L, Xu HQ, Shi YW, Yi YH, He N, Liao WP. Epilepsy-associated genes. Seizure 2016; 44:11-20. [PMID: 28007376 DOI: 10.1016/j.seizure.2016.11.030] [Citation(s) in RCA: 275] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/03/2016] [Accepted: 11/30/2016] [Indexed: 10/20/2022] Open
Abstract
Development in genetic technology has led to the identification of an increasing number of genes associated with epilepsy. These discoveries will both provide the basis for including genetic tests in clinical practice and improve diagnosis and treatment of epilepsy. By searching through several databases (OMIM, HGMD, and EpilepsyGene) and recent publications on PubMed, we found 977 genes that are associated with epilepsy. We classified these genes into 4 categories according to the manifestation of epilepsy in phenotypes. We found 84 genes that are considered as epilepsy genes: genes that cause epilepsies or syndromes with epilepsy as the core symptom. 73 genes were listed as neurodevelopment-associated genes: genes associated with both brain-development malformations and epilepsy. Several genes (536) were epilepsy-related: genes associated with both physical or other systemic abnormalities and epilepsy or seizures. We found 284 additional genes putatively associated with epilepsy; this requires further verification. These integrated data will provide new insights useful for both including genetic tests in the clinical practice and evaluating the results of genetic tests. We also summarized the epilepsy-associated genes according to their function, with the goal to better characterize the association between genes and epilepsies and to further understand the mechanisms underlying epilepsy.
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Affiliation(s)
- Jie Wang
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China; Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Zhi-Jian Lin
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China; Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Liu Liu
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China; Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Hai-Qing Xu
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China; Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China; Department of Neurology, Affiliated Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Yi-Wu Shi
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China; Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Yong-Hong Yi
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China; Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Na He
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China; Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China.
| | - Wei-Ping Liao
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou 510260, China; Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China.
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107
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Desikan RS, Barkovich AJ. Malformations of cortical development. Ann Neurol 2016; 80:797-810. [PMID: 27862206 PMCID: PMC5177533 DOI: 10.1002/ana.24793] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 09/26/2016] [Accepted: 09/26/2016] [Indexed: 01/05/2023]
Abstract
Malformations of cortical development (MCDs) compose a diverse range of disorders that are common causes of neurodevelopmental delay and epilepsy. With improved imaging and genetic methodologies, the underlying molecular and pathobiological characteristics of several MCDs have been recently elucidated. In this review, we discuss genetic and molecular alterations that disrupt normal cortical development, with emphasis on recent discoveries, and provide detailed radiological features of the most common and important MCDs. Ann Neurol 2016;80:797-810.
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Affiliation(s)
- Rahul S. Desikan
- Neuroradiology Section, Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA
| | - A. James Barkovich
- Neuroradiology Section, Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA
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108
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Regional selection of the brain size regulating gene CASC5 provides new insight into human brain evolution. Hum Genet 2016; 136:193-204. [PMID: 27878434 DOI: 10.1007/s00439-016-1748-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Accepted: 11/15/2016] [Indexed: 12/25/2022]
Abstract
Human evolution is marked by a continued enlargement of the brain. Previous studies on human brain evolution focused on identifying sequence divergences of brain size regulating genes between humans and nonhuman primates. However, the evolutionary pattern of the brain size regulating genes during recent human evolution is largely unknown. We conducted a comprehensive analysis of the brain size regulating gene CASC5 and found that in recent human evolution, CASC5 has accumulated many modern human specific amino acid changes, including two fixed changes and six polymorphic changes. Among human populations, 4 of the 6 amino acid polymorphic sites have high frequencies of derived alleles in East Asians, but are rare in Europeans and Africans. We proved that this between-population allelic divergence was caused by regional Darwinian positive selection in East Asians. Further analysis of brain image data of Han Chinese showed significant associations of the amino acid polymorphic sites with gray matter volume. Hence, CASC5 may contribute to the morphological and structural changes of the human brain during recent evolution. The observed between-population divergence of CASC5 variants was driven by natural selection that tends to favor a larger gray matter volume in East Asians.
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109
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Jayaraman D, Kodani A, Gonzalez DM, Mancias JD, Mochida GH, Vagnoni C, Johnson J, Krogan N, Harper JW, Reiter JF, Yu TW, Bae BI, Walsh CA. Microcephaly Proteins Wdr62 and Aspm Define a Mother Centriole Complex Regulating Centriole Biogenesis, Apical Complex, and Cell Fate. Neuron 2016; 92:813-828. [PMID: 27974163 DOI: 10.1016/j.neuron.2016.09.056] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Revised: 06/13/2016] [Accepted: 09/19/2016] [Indexed: 01/11/2023]
Abstract
Mutations in several genes encoding centrosomal proteins dramatically decrease the size of the human brain. We show that Aspm (abnormal spindle-like, microcephaly-associated) and Wdr62 (WD repeat-containing protein 62) interact genetically to control brain size, with mice lacking Wdr62, Aspm, or both showing gene dose-related centriole duplication defects that parallel the severity of the microcephaly and increased ectopic basal progenitors, suggesting premature delamination from the ventricular zone. Wdr62 and Aspm localize to the proximal end of the mother centriole and interact physically, with Wdr62 required for Aspm localization, and both proteins, as well as microcephaly protein Cep63, required to localize CENPJ/CPAP/Sas-4, a final common target. Unexpectedly, Aspm and Wdr62 are required for normal apical complex localization and apical epithelial structure, providing a plausible unifying mechanism for the premature delamination and precocious differentiation of progenitors. Together, our results reveal links among centrioles, apical proteins, and cell fate, and illuminate how alterations in these interactions can dynamically regulate brain size.
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Affiliation(s)
- Divya Jayaraman
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA; Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA; Harvard-MIT MD-PhD Program, Harvard Medical School, Boston, MA 02115, USA
| | - Andrew Kodani
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Dilenny M Gonzalez
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Joseph D Mancias
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Division of Genomic Stability and DNA Repair, Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Ganeshwaran H Mochida
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Pediatric Neurology Unit, Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Cristiana Vagnoni
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK
| | - Jeffrey Johnson
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Nevan Krogan
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - J Wade Harper
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Jeremy F Reiter
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Timothy W Yu
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Program in Medical and Population Genetics, Broad Institute of MIT and Harvard University, Cambridge, MA 02142, USA.
| | - Byoung-Il Bae
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
| | - Christopher A Walsh
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA; Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Program in Medical and Population Genetics, Broad Institute of MIT and Harvard University, Cambridge, MA 02142, USA; Department of Neurology, Harvard Medical School, Boston, MA 02115, USA.
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110
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Abstract
Centrosomes are complex structures, which are embedded into the opposite poles of the mitotic spindle of most animals, acting as microtubule organizing centres. Surprisingly, in several biological systems, such as flies, chicken, or human cells, centrosomes are not essential for cell division. Nonetheless, they ensure faithful chromosome segregation. Moreover, mis-functioning centrosomes can act in a dominant-negative manner, resulting in erroneous mitotic progression. Here, I review the mechanisms by which centrosomes contribute to proper spindle organization and faithful chromosome segregation under physiological conditions and discuss how errors in centrosome function impair transmission of the genomic material in a pathological setting.
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111
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Telencephalic Flexure and Malformations of the Lateral Cerebral (Sylvian) Fissure. Pediatr Neurol 2016; 63:23-38. [PMID: 27590993 DOI: 10.1016/j.pediatrneurol.2016.05.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Accepted: 05/04/2016] [Indexed: 11/20/2022]
Abstract
After sagittal division of the prosencephalon at 4.5 weeks of gestation, the early fetal cerebral hemisphere bends or rotates posteroventrally from seven weeks of gestation. The posterior pole of the telencephalon thus becomes not the occipital but the temporal lobe as the telencephalic flexure forms the operculum and finally the lateral cerebral or Sylvian fissure. The ventral part is infolded to become the insula. The frontal and temporal lips of the Sylvian fissure, as well as the insula, all derive from the ventral margin of the primitive telencephalon, hence may be influenced by genetic mutations with a ventrodorsal gradient of expression. The telencephalic flexure also contributes to a shift of the hippocampus from a dorsal to a ventral position, the early rostral pole of the hippocampus becoming caudal and dorsal becoming ventral. The occipital horn is the most recent recess of the lateral ventricle, hence most vulnerable to anatomic variations that affect the calcarine fissure. Many major malformations include lack of telencephalic flexure (holoprosencephaly, extreme micrencephaly) or dysplastic Sylvian fissure (lissencephalies, hemimegalencephaly, schizencephaly). Although fissures and sulci are genetically programmed, mechanical forces of growth and volume expansion are proposed to be mainly extrinsic (including ventricles) for fissures and intrinsic for sulci. In fetal hydrocephalus, the telencephalic flexure is less affected because ventricular dilatation occurs later in gestation. Flexures can be detected prenatally by ultrasound and fetal magnetic resonance imaging and should be described neuropathologically in cerebral malformations.
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112
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Kim JH, Shinde D, Reijnders M, Hauser N, Belmonte R, Wilson G, Bosch D, Bubulya P, Shashi V, Petrovski S, Stone J, Park E, Veltman J, Sinnema M, Stumpel C, Draaisma J, Nicolai J, Yntema H, Lindstrom K, de Vries B, Jewett T, Santoro S, Vogt J, Bachman K, Seeley A, Krokosky A, Turner C, Rohena L, Hempel M, Kortüm F, Lessel D, Neu A, Strom T, Wieczorek D, Bramswig N, Laccone F, Behunova J, Rehder H, Gordon C, Rio M, Romana S, Tang S, El-Khechen D, Cho M, McWalter K, Douglas G, Baskin B, Begtrup A, Funari T, Schoch K, Stegmann A, Stevens S, Zhang DE, Traver D, Yao X, MacArthur D, Brunner H, Mancini G, Myers R, Owen L, Lim ST, Stachura D, Vissers L, Ahn EY, Vissers LELM, Ahn EYE. De Novo Mutations in SON Disrupt RNA Splicing of Genes Essential for Brain Development and Metabolism, Causing an Intellectual-Disability Syndrome. Am J Hum Genet 2016; 99:711-719. [PMID: 27545680 PMCID: PMC5011044 DOI: 10.1016/j.ajhg.2016.06.029] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 06/24/2016] [Indexed: 12/01/2022] Open
Abstract
The overall understanding of the molecular etiologies of intellectual disability (ID) and developmental delay (DD) is increasing as next-generation sequencing technologies identify genetic variants in individuals with such disorders. However, detailed analyses conclusively confirming these variants, as well as the underlying molecular mechanisms explaining the diseases, are often lacking. Here, we report on an ID syndrome caused by de novo heterozygous loss-of-function (LoF) mutations in SON. The syndrome is characterized by ID and/or DD, malformations of the cerebral cortex, epilepsy, vision problems, musculoskeletal abnormalities, and congenital malformations. Knockdown of son in zebrafish resulted in severe malformation of the spine, brain, and eyes. Importantly, analyses of RNA from affected individuals revealed that genes critical for neuronal migration and cortex organization (TUBG1, FLNA, PNKP, WDR62, PSMD3, and HDAC6) and metabolism (PCK2, PFKL, IDH2, ACY1, and ADA) are significantly downregulated because of the accumulation of mis-spliced transcripts resulting from erroneous SON-mediated RNA splicing. Our data highlight SON as a master regulator governing neurodevelopment and demonstrate the importance of SON-mediated RNA splicing in human development.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Lisenka E L M Vissers
- Department of Human Genetics, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands.
| | - Eun-Young Erin Ahn
- Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA; Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA.
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113
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Stark AE. The genetic epidemiology of the form of microcephaly ascribed to mutation at the WDR62 locus. ANNALS OF TRANSLATIONAL MEDICINE 2016; 4:281. [PMID: 27570775 DOI: 10.21037/atm.2016.07.08] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The disorder associated with mutation in the WDR62 gene MCPH2 is taken as the prototype of a condition which has a recessive mode of inheritance. The mutant homozygote has relatively lower fitness defined by the selection coefficient. Formulae which relate the incidence of the disorder to the mutation rate and the gene frequency in equilibrium when some degree of inbreeding occurs in the population are given.
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Affiliation(s)
- Alan Edmund Stark
- School of Mathematics and Statistics, F07, University of Sydney, NSW, Australia
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114
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The function of sperm-associated antigen 6 in neuronal proliferation and differentiation. J Mol Histol 2016; 47:531-540. [PMID: 27566703 DOI: 10.1007/s10735-016-9694-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 08/18/2016] [Indexed: 12/11/2022]
Abstract
Sperm-associated antigen 6 (SPAG6) is initially found in human testis and is essential for sperm motility and male fertility. Later studies indicate that it also express in the chick Central Nervous System and human embryonic stem cells. However, the function of Spag6 in cortical development is still largely unclear. Using in utero electroporation, we showed that overexpression of Spag6 induced the transfected cells excluded from the proliferation zone of the mouse cortex. Ki67 Co-labeling and BrdU incorporation experiment suggested that overexpression of Spag6 inhibited proliferation of neural progenitor cells. Furthermore, we demonstrated that Spag6-overexpressing cells preferred to differentiated into neurons, which could be labeled by Brn2, rather than GFAP positive astrocytes. Taken together, our data indicate that Spag6 plays an essential role in the process of neuronal proliferation and differentiation.
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115
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Betizeau M, Dehay C. From stem cells to comparative corticogenesis: a bridge too far? Stem Cell Investig 2016; 3:39. [PMID: 27668246 DOI: 10.21037/sci.2016.08.02] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 08/03/2016] [Indexed: 11/06/2022]
Abstract
It has been hypothesized that the higher number of neurons in human cortex compared to the chimpanzee and other primate species is key to high cognitive function. Are human cortical precursors endowed with specific properties that drive greater neuronal expansion than in other non-human primates? Otani et al. 2016 addressed this issue taking advantage of comparative in vitro corticogenesis models based on human, chimpanzee and macaque pluripotent stem cells. Clonal analysis revealed a heterochrony of early developmental events possibly leading to a relatively higher expansion of human cortical precursor population. In absence of evidence going beyond putative correlation, the claim that stem cell models of cortical development indicate mechanism of cortical size regulation needs to be further examined notably with respect to in vivo observations of cortical precursor lineages.
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Affiliation(s)
- Marion Betizeau
- Institute of Neuroinformatics, University of Zurich and ETH Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Colette Dehay
- Univ Lyon, Universite Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500 Bron, France
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116
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Basit S, Al-Harbi KM, Alhijji SAM, Albalawi AM, Alharby E, Eldardear A, Samman MI. CIT, a gene involved in neurogenic cytokinesis, is mutated in human primary microcephaly. Hum Genet 2016; 135:1199-207. [DOI: 10.1007/s00439-016-1724-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Accepted: 08/09/2016] [Indexed: 12/22/2022]
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117
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Hori A, Toda T. Regulation of centriolar satellite integrity and its physiology. Cell Mol Life Sci 2016; 74:213-229. [PMID: 27484406 PMCID: PMC5219025 DOI: 10.1007/s00018-016-2315-x] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 07/14/2016] [Accepted: 07/21/2016] [Indexed: 01/01/2023]
Abstract
Centriolar satellites comprise cytoplasmic granules that are located around the centrosome. Their molecular identification was first reported more than a quarter of a century ago. These particles are not static in the cell but instead constantly move around the centrosome. Over the last decade, significant advances in their molecular compositions and biological functions have been achieved due to comprehensive proteomics and genomics, super-resolution microscopy analyses and elegant genetic manipulations. Centriolar satellites play pivotal roles in centrosome assembly and primary cilium formation through the delivery of centriolar/centrosomal components from the cytoplasm to the centrosome. Their importance is further underscored by the fact that mutations in genes encoding satellite components and regulators lead to various human disorders such as ciliopathies. Moreover, the most recent findings highlight dynamic structural remodelling in response to internal and external cues and unexpected positive feedback control that is exerted from the centrosome for centriolar satellite integrity.
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Affiliation(s)
- Akiko Hori
- Lincoln's Inn Fields Laboratory, The Francis Crick Institute, 44 Lincoln's Inn Fields, London, WC2A 3LY, UK.,Developmental Biomedical Science, Graduate School of Biological Sciences, Nara Institute of Science and Technology (NAIST), 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan
| | - Takashi Toda
- Lincoln's Inn Fields Laboratory, The Francis Crick Institute, 44 Lincoln's Inn Fields, London, WC2A 3LY, UK. .,Department of Molecular Biotechnology, Hiroshima Research Center for Healthy Aging (HiHA), Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, 739-8530, Japan.
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118
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Witteveen JS, Willemsen MH, Dombroski TCD, van Bakel NHM, Nillesen WM, van Hulten JA, Jansen EJR, Verkaik D, Veenstra-Knol HE, van Ravenswaaij-Arts CMA, Wassink-Ruiter JSK, Vincent M, David A, Le Caignec C, Schieving J, Gilissen C, Foulds N, Rump P, Strom T, Cremer K, Zink AM, Engels H, de Munnik SA, Visser JE, Brunner HG, Martens GJM, Pfundt R, Kleefstra T, Kolk SM. Haploinsufficiency of MeCP2-interacting transcriptional co-repressor SIN3A causes mild intellectual disability by affecting the development of cortical integrity. Nat Genet 2016; 48:877-87. [PMID: 27399968 DOI: 10.1038/ng.3619] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 06/15/2016] [Indexed: 12/13/2022]
Abstract
Numerous genes are associated with neurodevelopmental disorders such as intellectual disability and autism spectrum disorder (ASD), but their dysfunction is often poorly characterized. Here we identified dominant mutations in the gene encoding the transcriptional repressor and MeCP2 interactor switch-insensitive 3 family member A (SIN3A; chromosome 15q24.2) in individuals who, in addition to mild intellectual disability and ASD, share striking features, including facial dysmorphisms, microcephaly and short stature. This phenotype is highly related to that of individuals with atypical 15q24 microdeletions, linking SIN3A to this microdeletion syndrome. Brain magnetic resonance imaging showed subtle abnormalities, including corpus callosum hypoplasia and ventriculomegaly. Intriguingly, in vivo functional knockdown of Sin3a led to reduced cortical neurogenesis, altered neuronal identity and aberrant corticocortical projections in the developing mouse brain. Together, our data establish that haploinsufficiency of SIN3A is associated with mild syndromic intellectual disability and that SIN3A can be considered to be a key transcriptional regulator of cortical brain development.
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Affiliation(s)
- Josefine S Witteveen
- Department of Molecular Animal Physiology, Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, the Netherlands
| | - Marjolein H Willemsen
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behavior, Nijmegen, the Netherlands
| | - Thaís C D Dombroski
- Department of Molecular Animal Physiology, Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, the Netherlands
| | - Nick H M van Bakel
- Department of Molecular Animal Physiology, Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, the Netherlands
| | - Willy M Nillesen
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behavior, Nijmegen, the Netherlands
| | - Josephus A van Hulten
- Department of Molecular Animal Physiology, Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, the Netherlands
| | - Eric J R Jansen
- Department of Molecular Animal Physiology, Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, the Netherlands
| | - Dave Verkaik
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behavior, Nijmegen, the Netherlands
| | - Hermine E Veenstra-Knol
- Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | | | | | - Marie Vincent
- Centre Hospitalier Universitaire de Nantes, Service de Génétique Médicale, Nantes, France
| | - Albert David
- Centre Hospitalier Universitaire de Nantes, Service de Génétique Médicale, Nantes, France
| | - Cedric Le Caignec
- Centre Hospitalier Universitaire de Nantes, Service de Génétique Médicale, Nantes, France.,Laboratoire de Physiopathologie de la Résorption Osseuse et Thérapie des Tumeurs Osseuses Primitives, Faculté de Médecine, INSERM UMRS 957, Nantes, France
| | - Jolanda Schieving
- Department of Neurology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Christian Gilissen
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behavior, Nijmegen, the Netherlands
| | - Nicola Foulds
- Wessex Clinical Genetics Services, University Hospital Southampton National Health Service Foundation Trust, Princess Anne Hospital, Southampton, UK.,Department of Human Genetics and Genomic Medicine, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Patrick Rump
- Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Tim Strom
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany.,Institute of Human Genetics, Technische Universität München, Munich, Germany
| | - Kirsten Cremer
- Institute of Human Genetics, University of Bonn, Bonn, Germany
| | | | - Hartmut Engels
- Institute of Human Genetics, University of Bonn, Bonn, Germany
| | - Sonja A de Munnik
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behavior, Nijmegen, the Netherlands
| | - Jasper E Visser
- Department of Molecular Animal Physiology, Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, the Netherlands.,Department of Neurology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands.,Department of Neurology, Amphia Hospital Breda, Berda, the Netherlands
| | - Han G Brunner
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behavior, Nijmegen, the Netherlands
| | - Gerard J M Martens
- Department of Molecular Animal Physiology, Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, the Netherlands
| | - Rolph Pfundt
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behavior, Nijmegen, the Netherlands
| | - Tjitske Kleefstra
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behavior, Nijmegen, the Netherlands
| | - Sharon M Kolk
- Department of Molecular Animal Physiology, Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, the Netherlands
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119
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Nair P, Hamzeh AR, Mohamed M, Saif F, Tawfiq N, El Halik M, Al-Ali MT, Bastaki F. Microcephalic primordial dwarfism in an Emirati patient with PNKP mutation. Am J Med Genet A 2016; 170:2127-32. [PMID: 27232581 DOI: 10.1002/ajmg.a.37766] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 05/09/2016] [Indexed: 11/11/2022]
Abstract
Microcephaly is a rare neurological condition, both in isolation and when it occurs as part of a syndrome. One of the syndromic forms of microcephaly is microcephaly, seizures and developmental delay (MCSZ) (OMIM #613402), a rare autosomal recessive neurodevelopmental disorder with a range of phenotypic severity, and known to be caused by mutations in the polynucleotide kinase 3' phosphatase (PNKP) gene. The PNK protein is a key enzyme involved in the repair of single and double stranded DNA breaks, a process which is particularly important in the nervous system. We describe an Emirati patient who presented with microcephaly, short stature, uncontrollable tonic-clonic seizures, facial dysmorphism, and developmental delay, while at the same time showing evidence of brain atrophy and agenesis of the corpus callosum. We used whole exome sequencing to identify homozygosity for a missense c.1385G > C (p.Arg462Pro) mutation in PNKP in the patient and heterozygosity for this mutation in her consanguineous parents. The Arg 462 residue forms a part of the lid subdomain helix of the P-loop Kinase domain. Although our patient's phenotype resembled that of MCSZ, the short stature and evidence of brain atrophy distinguished it from other classic cases of the condition. The report raises the question of whether to consider this case as an atypical variant of MCSZ or as a novel form of microcephalic primordial dwarfism. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
| | | | - Madiha Mohamed
- Pediatric Department, Latifa Hospital, Dubai Health Authority, Dubai, UAE
| | - Fatima Saif
- Pediatric Department, Latifa Hospital, Dubai Health Authority, Dubai, UAE
| | - Nafisa Tawfiq
- Pediatric Department, Latifa Hospital, Dubai Health Authority, Dubai, UAE
| | - Majdi El Halik
- Pediatric Department, Latifa Hospital, Dubai Health Authority, Dubai, UAE
| | | | - Fatma Bastaki
- Pediatric Department, Latifa Hospital, Dubai Health Authority, Dubai, UAE
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120
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Fernández V, Llinares-Benadero C, Borrell V. Cerebral cortex expansion and folding: what have we learned? EMBO J 2016; 35:1021-44. [PMID: 27056680 PMCID: PMC4868950 DOI: 10.15252/embj.201593701] [Citation(s) in RCA: 222] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 02/23/2016] [Accepted: 03/17/2016] [Indexed: 01/22/2023] Open
Abstract
One of the most prominent features of the human brain is the fabulous size of the cerebral cortex and its intricate folding. Cortical folding takes place during embryonic development and is important to optimize the functional organization and wiring of the brain, as well as to allow fitting a large cortex in a limited cranial volume. Pathological alterations in size or folding of the human cortex lead to severe intellectual disability and intractable epilepsy. Hence, cortical expansion and folding are viewed as key processes in mammalian brain development and evolution, ultimately leading to increased intellectual performance and, eventually, to the emergence of human cognition. Here, we provide an overview and discuss some of the most significant advances in our understanding of cortical expansion and folding over the last decades. These include discoveries in multiple and diverse disciplines, from cellular and molecular mechanisms regulating cortical development and neurogenesis, genetic mechanisms defining the patterns of cortical folds, the biomechanics of cortical growth and buckling, lessons from human disease, and how genetic evolution steered cortical size and folding during mammalian evolution.
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Affiliation(s)
- Virginia Fernández
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas & Universidad Miguel Hernández, Sant Joan d'Alacant, Spain
| | - Cristina Llinares-Benadero
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas & Universidad Miguel Hernández, Sant Joan d'Alacant, Spain
| | - Víctor Borrell
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas & Universidad Miguel Hernández, Sant Joan d'Alacant, Spain
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121
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Xu D, Xu Z. Driving WDR62 to the pole. Cell Cycle 2016; 15:1180-1. [PMID: 27110649 DOI: 10.1080/15384101.2016.1154374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Affiliation(s)
- Dan Xu
- a State Key Laboratory of Molecular Developmental Biology; Institute of Genetics and Developmental Biology, Chinese Academy of Sciences ; 1 W Beichen Rd. Beijing , China.,b Institute of Life Sciences; Fuzhou University ; Fuzhou , China
| | - Zhiheng Xu
- a State Key Laboratory of Molecular Developmental Biology; Institute of Genetics and Developmental Biology, Chinese Academy of Sciences ; 1 W Beichen Rd. Beijing , China.,c Parkinson's disease center; Beijing Institute for Brain Disorders ; Beijing , China.,d The translational medical center for stem cell therapy; Shanghai East Hospital; Tongji University School of Medicine ; Shanghai , China
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122
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Lim NR, Yeap YYC, Zhao TT, Yip YY, Wong SC, Xu D, Ang CS, Williamson NA, Xu Z, Bogoyevitch MA, Ng DCH. Opposing roles for JNK and Aurora A in regulating the association of WDR62 with spindle microtubules. J Cell Sci 2016; 128:527-40. [PMID: 25501809 DOI: 10.1242/jcs.157537] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
WD40-repeat protein 62 (WDR62) is a spindle pole protein required for normal cell division and neuroprogenitor differentiation during brain development. Microcephaly-associated mutations in WDR62 lead to mitotic mislocalization, highlighting a crucial requirement for precise WDR62 spatiotemporal distribution, although the regulatory mechanisms are unknown. Here, we demonstrate that the WD40-repeat region of WDR62 is required for microtubule association, whereas the disordered C-terminal region regulates cell-cycle-dependent compartmentalization. In agreement with a functional requirement for the WDR62–JNK1 complex during neurogenesis, WDR62 specifically recruits JNK1 (also known as MAPK8), but not JNK2 (also known as MAPK9), to the spindle pole. However, JNK-mediated phosphorylation of WDR62 T1053 negatively regulated microtubule association, and loss of JNK signaling resulted in constitutive WDR62 localization to microtubules irrespective of cell cycle stage. In contrast, we identified that Aurora A kinase (AURKA) and WDR62 were in complex and that AURKA-mediated phosphorylation was required for the spindle localization of WDR62 during mitosis. Our studies highlight complex regulation of WDR62 localization, with opposing roles for JNK and AURKA in determining its spindle association.
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123
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Zhang F, Yu J, Yang T, Xu D, Chi Z, Xia Y, Xu Z. A Novel c-Jun N-terminal Kinase (JNK) Signaling Complex Involved in Neuronal Migration during Brain Development. J Biol Chem 2016; 291:11466-75. [PMID: 27026702 DOI: 10.1074/jbc.m116.716811] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Indexed: 12/23/2022] Open
Abstract
Disturbance of neuronal migration may cause various neurological disorders. Both the transforming growth factor-β (TGF-β) signaling and microcephaly-associated protein WDR62 are important for neuronal migration during brain development; however, the underlying molecular mechanisms involved remain unclear. We show here that knock-out or knockdown of Tak1 (TGFβ-activated kinase 1) and Jnk2 (c-Jun N-terminal kinase 2) perturbs neuronal migration during cortical development and that the migration defects incurred by knock-out and/or knockdown of Tβr2 (type II TGF-β receptor) or Tak1 can be partially rescued by expression of TAK1 and JNK2, respectively. Furthermore, TAK1 forms a protein complex with RAC1 and two scaffold proteins of the JNK pathway, the microcephaly-associated protein WDR62 and the RAC1-interacting protein POSH (plenty of Src homology). Components of the complex coordinate with each other in the regulation of TAK1 as well as JNK activities. We suggest that unique JNK protein complexes are involved in the diversified biological and pathological functions during brain development and pathogenesis of diseases.
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Affiliation(s)
- Feng Zhang
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, the University of Chinese Academy of Sciences, Beijing 100101, and
| | - Jingwen Yu
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101
| | - Tao Yang
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101
| | - Dan Xu
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101
| | - Zhixia Chi
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101
| | - Yanheng Xia
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, the University of Chinese Academy of Sciences, Beijing 100101, and
| | - Zhiheng Xu
- From the State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, the Translational Medical Center for Stem Cell Therapy, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, the Parkinson's Disease Center, Beijing Institute for Brain Disorders, Beijing 100101, China
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124
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Chavali PL, Chandrasekaran G, Barr AR, Tátrai P, Taylor C, Papachristou EK, Woods CG, Chavali S, Gergely F. A CEP215-HSET complex links centrosomes with spindle poles and drives centrosome clustering in cancer. Nat Commun 2016; 7:11005. [PMID: 26987684 PMCID: PMC4802056 DOI: 10.1038/ncomms11005] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 02/10/2016] [Indexed: 01/09/2023] Open
Abstract
Numerical centrosome aberrations underlie certain developmental abnormalities and may promote cancer. A cell maintains normal centrosome numbers by coupling centrosome duplication with segregation, which is achieved through sustained association of each centrosome with a mitotic spindle pole. Although the microcephaly- and primordial dwarfism-linked centrosomal protein CEP215 has been implicated in this process, the molecular mechanism responsible remains unclear. Here, using proteomic profiling, we identify the minus end-directed microtubule motor protein HSET as a direct binding partner of CEP215. Targeted deletion of the HSET-binding domain of CEP215 in vertebrate cells causes centrosome detachment and results in HSET depletion at centrosomes, a phenotype also observed in CEP215-deficient patient-derived cells. Moreover, in cancer cells with centrosome amplification, the CEP215-HSET complex promotes the clustering of extra centrosomes into pseudo-bipolar spindles, thereby ensuring viable cell division. Therefore, stabilization of the centrosome-spindle pole interface by the CEP215-HSET complex could promote survival of cancer cells containing supernumerary centrosomes.
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Affiliation(s)
- Pavithra L. Chavali
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Robinson Way, Cambridge CB2 0RE, UK
| | - Gayathri Chandrasekaran
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Robinson Way, Cambridge CB2 0RE, UK
| | - Alexis R. Barr
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Robinson Way, Cambridge CB2 0RE, UK
| | - Péter Tátrai
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Robinson Way, Cambridge CB2 0RE, UK
| | - Chris Taylor
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Robinson Way, Cambridge CB2 0RE, UK
| | - Evaggelia K. Papachristou
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Robinson Way, Cambridge CB2 0RE, UK
| | - C. Geoffrey Woods
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Sreenivas Chavali
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Fanni Gergely
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Robinson Way, Cambridge CB2 0RE, UK
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125
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Pervaiz N, Abbasi AA. Molecular evolution of WDR62, a gene that regulates neocorticogenesis. Meta Gene 2016; 9:1-9. [PMID: 27114917 PMCID: PMC4833054 DOI: 10.1016/j.mgene.2016.02.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 02/23/2016] [Indexed: 02/02/2023] Open
Abstract
Human brain evolution is characterized by dramatic expansion in cerebral cortex size. WDR62 (WD repeat domain 62) is one of the important gene in controlling human cortical development. Mutations in WDR62 lead to primary microcephaly, a neurodevelopmental disease characterized by three to four fold reduction in cerebral cortex size of affected individuals. This study analyzes comparative protein evolutionary rate to provide a useful insight into the molecular evolution of WDR62 and hence pinpointed human specific amino acid replacements. Comparative analysis of human WDR62 with two archaic humans (Neanderthals and Denisovans) and modern human populations revealed that five hominin specific amino acid residues (human specific amino acids shared with two archaic humans) might have been accumulated in the common ancestor of extinct archaic humans and modern humans about 550,000–765,000 years ago. Collectively, the data demonstrates an acceleration of WDR62 sequence evolution in hominin lineage and suggests that the ability of WDR62 protein to mediate the neurogenesis has been altered in the course of hominin evolution. We trace the evolutionary history of WDR62 and its putative paralogs. We identify accelerated sequence evolution in human WDR62. We pinpoint eight human specific amino acid sites that reside on the C-terminal. Out of eight, six sites are shared with archaic humans.
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Affiliation(s)
- Nashaiman Pervaiz
- National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan
| | - Amir Ali Abbasi
- National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan
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126
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Hettne KM, Thompson M, van Haagen HHHBM, van der Horst E, Kaliyaperumal R, Mina E, Tatum Z, Laros JFJ, van Mulligen EM, Schuemie M, Aten E, Li TS, Bruskiewich R, Good BM, Su AI, Kors JA, den Dunnen J, van Ommen GJB, Roos M, ‘t Hoen PA, Mons B, Schultes EA. The Implicitome: A Resource for Rationalizing Gene-Disease Associations. PLoS One 2016; 11:e0149621. [PMID: 26919047 PMCID: PMC4769089 DOI: 10.1371/journal.pone.0149621] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 02/03/2016] [Indexed: 11/19/2022] Open
Abstract
High-throughput experimental methods such as medical sequencing and genome-wide association studies (GWAS) identify increasingly large numbers of potential relations between genetic variants and diseases. Both biological complexity (millions of potential gene-disease associations) and the accelerating rate of data production necessitate computational approaches to prioritize and rationalize potential gene-disease relations. Here, we use concept profile technology to expose from the biomedical literature both explicitly stated gene-disease relations (the explicitome) and a much larger set of implied gene-disease associations (the implicitome). Implicit relations are largely unknown to, or are even unintended by the original authors, but they vastly extend the reach of existing biomedical knowledge for identification and interpretation of gene-disease associations. The implicitome can be used in conjunction with experimental data resources to rationalize both known and novel associations. We demonstrate the usefulness of the implicitome by rationalizing known and novel gene-disease associations, including those from GWAS. To facilitate the re-use of implicit gene-disease associations, we publish our data in compliance with FAIR Data Publishing recommendations [https://www.force11.org/group/fairgroup] using nanopublications. An online tool (http://knowledge.bio) is available to explore established and potential gene-disease associations in the context of other biomedical relations.
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Affiliation(s)
- Kristina M. Hettne
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
- * E-mail:
| | - Mark Thompson
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Eelke van der Horst
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Rajaram Kaliyaperumal
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Eleni Mina
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Zuotian Tatum
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Jeroen F. J. Laros
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Erik M. van Mulligen
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
- Department of Medical Informatics, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Martijn Schuemie
- Department of Medical Informatics, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Emmelien Aten
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Tong Shu Li
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, United States of America
| | | | - Benjamin M. Good
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, United States of America
| | - Andrew I. Su
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, United States of America
| | - Jan A. Kors
- Department of Medical Informatics, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Johan den Dunnen
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Gert-Jan B. van Ommen
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Marco Roos
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Peter A.C. ‘t Hoen
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Barend Mons
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
- Dutch Techcentre for Life Sciences, Utrecht, The Netherlands
| | - Erik A. Schultes
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
- Leiden Institute for Advanced Computer Science, Leiden, The Netherlands
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127
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Ramdas Nair A, Singh P, Salvador Garcia D, Rodriguez-Crespo D, Egger B, Cabernard C. The Microcephaly-Associated Protein Wdr62/CG7337 Is Required to Maintain Centrosome Asymmetry in Drosophila Neuroblasts. Cell Rep 2016; 14:1100-1113. [PMID: 26804909 DOI: 10.1016/j.celrep.2015.12.097] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 12/10/2015] [Accepted: 12/21/2015] [Indexed: 12/31/2022] Open
Abstract
Centrosome asymmetry has been implicated in stem cell fate maintenance in both flies and vertebrates, but the underlying molecular mechanisms are incompletely understood. Here, we report that loss of CG7337, the fly ortholog of WDR62, compromises interphase centrosome asymmetry in fly neural stem cells (neuroblasts). Wdr62 maintains an active interphase microtubule-organizing center (MTOC) by stabilizing microtubules (MTs), which are necessary for sustained recruitment of Polo/Plk1 to the pericentriolar matrix (PCM) and downregulation of Pericentrin-like protein (Plp). The loss of an active MTOC in wdr62 mutants compromises centrosome positioning, spindle orientation, and biased centrosome segregation. wdr62 mutant flies also have an ∼40% reduction in brain size as a result of cell-cycle delays. We propose that CG7337/Wdr62, a microtubule-associated protein, is required for the maintenance of interphase microtubules, thereby regulating centrosomal Polo and Plp levels. Independent of this function, Wdr62 is also required for the timely mitotic entry of neural stem cells.
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Affiliation(s)
- Anjana Ramdas Nair
- Biozentrum, University of Basel, Klingelbergstrasse 50-70, 4056 Basel, Switzerland
| | - Priyanka Singh
- Biozentrum, University of Basel, Klingelbergstrasse 50-70, 4056 Basel, Switzerland
| | | | - David Rodriguez-Crespo
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Boris Egger
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Clemens Cabernard
- Biozentrum, University of Basel, Klingelbergstrasse 50-70, 4056 Basel, Switzerland.
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128
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Jansen AC, Robitaille Y, Honavar M, Mullatti N, Leventer RJ, Andermann E, Andermann F, Squier W. The histopathology of polymicrogyria: a series of 71 brain autopsy studies. Dev Med Child Neurol 2016; 58:39-48. [PMID: 26179148 DOI: 10.1111/dmcn.12840] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/09/2015] [Indexed: 11/30/2022]
Abstract
AIM Polymicrogyria (PMG) is one of the most common forms of cortical malformation yet the mechanism of its development remains unknown. This study describes the histopathological aspects of PMG in a large series including a significant proportion of fetal cases. METHOD We have reviewed the neuropathology and medical records of 44 fetuses and 27 children and adults in whom the cortical architecture was focally or diffusely replaced by one or more festooning bands of neurons. RESULTS The pial surface of the brain overlying the polymicrogyric cortex was abnormal in almost 90% of cases irrespective of the aetiology. This accords with animal studies indicating the importance of the leptomeninges in cortical development. The aetiology of PMG was highly heterogeneous and there was no correlation between cortical layering patterns and aetiology. PMG was almost always associated with other brain malformations. INTERPRETATION The inclusion of many fetal cases has allowed us to examine the early developmental stages of PMG. The study indicates the significance of surface signals responsible for human corticogenesis and the complex interaction between genetic and environmental factors leading to this common endpoint of cortical maldevelopment.
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Affiliation(s)
- Anna C Jansen
- Pediatric Neurology Unit, Department of Pediatrics, UZ Brussel, Brussels, Belgium.,Department of Public Health, Vrije Universiteit Brussel, Brussels, Belgium
| | - Yves Robitaille
- Department of Pathology, Centre Hospitalier Universitaire Sainte-Justine, Université de Montreal, Montreal, QC, Canada
| | - Mrinalini Honavar
- Department of Clinical Neuropathology, King's College Hospital, Denmark Hill, London, UK.,Service of Anatomic Pathology, Hospital Pedro Hispano, Matosinhos, Portugal
| | - Nandini Mullatti
- Department of Clinical Neurophysiology, King's College Hospital, Denmark Hill, London, UK
| | - Richard J Leventer
- Department of Neurology, University Department of Pediatrics, Murdoch Children's Research Institute, Royal Children's Hospital, The University of Melbourne, Parkville, Vic., Australia
| | - Eva Andermann
- Neurogenetics Unit, Montreal Neurological Hospital and Institute, and Departments of Neurology & Neurosurgery and Human Genetics, McGill University, Montreal, QC, Canada
| | - Frederick Andermann
- Seizure Clinic, Montreal Neurological Hospital and Institute, and Departments of Neurology & Neurosurgery and Paediatrics, McGill University, Montreal, QC, Canada
| | - Waney Squier
- Department of Neuropathology, Oxford University John Radcliffe Hospital, Oxford, UK
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129
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Yigit G, Wieczorek D, Bögershausen N, Beleggia F, Möller-Hartmann C, Altmüller J, Thiele H, Nürnberg P, Wollnik B. A syndrome of microcephaly, short stature, polysyndactyly, and dental anomalies caused by a homozygous KATNB1 mutation. Am J Med Genet A 2015; 170:728-33. [PMID: 26640080 DOI: 10.1002/ajmg.a.37484] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 11/04/2015] [Indexed: 12/26/2022]
Abstract
Using whole-exome sequencing, we identified a homozygous acceptor splice-site mutation in intron 6 of the KATNB1 gene in a patient from a consanguineous Turkish family who presented with congenital microcephaly, lissencephaly, short stature, polysyndactyly, and dental abnormalities. cDNA analysis revealed complete loss of the natural acceptor splice-site resulting either in the usage of an alternative, exonic acceptor splice-site inducing a frame-shift and premature protein truncation or, to a minor extent, in complete skipping of exon 7. Both effects most likely lead to complete loss of KATNB1 function. Homozygous and compound heterozygous mutations in KATNB1 have very recently been described as a cause of microcephaly with brain malformations and seizures. We extend the KATNB1 associated phenotype by describing a syndrome characterized by primordial dwarfism, lissencephaly, polysyndactyly, and dental anomalies, which is caused by a homozygous truncating KATNB1 mutation.
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Affiliation(s)
- Gökhan Yigit
- Institute of Human Genetics, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Dagmar Wieczorek
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Essen, Germany
| | - Nina Bögershausen
- Institute of Human Genetics, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Filippo Beleggia
- Institute of Human Genetics, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Claudia Möller-Hartmann
- Department of Neuroradiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Janine Altmüller
- Institute of Human Genetics, University of Cologne, Cologne, Germany.,Cologne Center for Genomics (CCG), University of Cologne, Cologne, Germany
| | - Holger Thiele
- Cologne Center for Genomics (CCG), University of Cologne, Cologne, Germany
| | - Peter Nürnberg
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Cologne Center for Genomics (CCG), University of Cologne, Cologne, Germany
| | - Bernd Wollnik
- Institute of Human Genetics, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
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130
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Refining the phenotype associated with CASC5 mutation. Neurogenetics 2015; 17:71-8. [PMID: 26626498 DOI: 10.1007/s10048-015-0468-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 11/14/2015] [Indexed: 02/03/2023]
Abstract
Autosomal recessive primary microcephaly is a neurodevelopmental disorder characterized by congenitally reduced head circumference by at least two standard deviations (SD) below the mean for age and gender. It is associated with nonprogressive mental retardation of variable degree, minimal neurological deficit with no evidence of architectural anomalies of the brain. So far, 12 genetic loci (MCPH1-12) and corresponding genes have been identified. Most of these encode centrosomal proteins. CASC5 is one the most recently unravelled genes responsible for MCPH with mutations reported in three consanguineous families of Moroccan origin, all of whom harboured the same CASC5 homozygous mutation (c.6125G>A; p.Met2041Ile). Here, we report the identification, by whole exome sequencing, of the same missense mutation in a consanguineous Algerian family. All patients exhibited a similar clinical phenotype, including congenital microcephaly with head circumferences ranging from -3 to -4 standard deviations (SD) after age 5 years, moderate to severe cognitive impairment, short stature (adult height -3 SD), dysmorphic features included a sloping forehead, thick eyebrows, synophris and a low columella. Severe vermis hypoplasia and a large cyst of the posterior fossa were observed in one patient. Close microsatellite markers showed identical alleles in the Algerian the previously and Moroccan patients. This study confirms the involvement of CASC5 in autosomal recessive microcephaly and supports the hypothesis of a founder effect of the c.6125G>A mutation. In addition, this report refines the phenotype of this newly recognized form of primary microcephaly.
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131
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Yigit G, Rosin N, Wollnik B. Molekulare Grundlagen der autosomal-rezessiven primären Mikrozephalie. MED GENET-BERLIN 2015. [DOI: 10.1007/s11825-015-0068-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Zusammenfassung
Die primäre autosomal-rezessive Mikrozephalie (MCPH) ist eine genetisch sehr heterogene Erkrankung, die klinisch definiert wird durch das Vorliegen einer kongenitalen, nicht progressiven Mikrozephalie, einer mentalen Retardierung variablen Ausmaßes bei weitgehend normaler Körpergröße und das Fehlen von zusätzlichen Fehlbildungen und weiteren neurologischen Befunden. Bislang konnten Mutationen in 14 verschiedenen Genen identifiziert werden, deren Produkte auf zellulärer Ebene insbesondere bei Vorgängen der Zellteilung, der Zellzyklusregulierung und bei der Aktivierung von DNA-Reparaturmechanismen nach DNA-Schädigungen eine wichtige Rolle spielen. Darüber hinaus sind auch syndromale Formen der Mikrozephalie bekannt, zu denen u. a. das Seckel-Syndrom sowie der mikrozephale osteodysplastische primordiale Kleinwuchs Typ II (MOPD II) zählen.
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Affiliation(s)
- Gökhan Yigit
- Aff1 grid.411097.a 000000008852305X Institut für Humangenetik Uniklinik Köln Köln Deutschland
- Aff2 grid.411984.1 0000000104825331 Institut für Humangenetik Universitätsmedizin Göttingen Heinrich-Düker-Weg 12 37073 Göttingen Deutschland
| | - Nadine Rosin
- Aff1 grid.411097.a 000000008852305X Institut für Humangenetik Uniklinik Köln Köln Deutschland
- Aff2 grid.411984.1 0000000104825331 Institut für Humangenetik Universitätsmedizin Göttingen Heinrich-Düker-Weg 12 37073 Göttingen Deutschland
| | - Bernd Wollnik
- Aff1 grid.411097.a 000000008852305X Institut für Humangenetik Uniklinik Köln Köln Deutschland
- Aff2 grid.411984.1 0000000104825331 Institut für Humangenetik Universitätsmedizin Göttingen Heinrich-Düker-Weg 12 37073 Göttingen Deutschland
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132
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Homem CCF, Repic M, Knoblich JA. Proliferation control in neural stem and progenitor cells. Nat Rev Neurosci 2015; 16:647-59. [PMID: 26420377 DOI: 10.1038/nrn4021] [Citation(s) in RCA: 236] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Neural circuit function can be drastically affected by variations in the number of cells that are produced during development or by a reduction in adult cell number owing to disease. For this reason, unique cell cycle and cell growth control mechanisms operate in the developing and adult brain. In Drosophila melanogaster and in mammalian neural stem and progenitor cells, these mechanisms are intricately coordinated with the developmental age and the nutritional, metabolic and hormonal state of the animal. Defects in neural stem cell proliferation that result in the generation of incorrect cell numbers or defects in neural stem cell differentiation can cause microcephaly or megalencephaly.
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Affiliation(s)
- Catarina C F Homem
- Institute of Molecular Biotechnology, Dr. Bohr Gasse 3, 1030, Vienna, Austria.,Chronic Diseases Research Center, NOVA Medical School, Rua Camara Pestana, 6, 1150-082 Lisbon, Portugal
| | - Marko Repic
- Institute of Molecular Biotechnology, Dr. Bohr Gasse 3, 1030, Vienna, Austria
| | - Jürgen A Knoblich
- Institute of Molecular Biotechnology, Dr. Bohr Gasse 3, 1030, Vienna, Austria
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133
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Vulto-van Silfhout AT, Nakagawa T, Bahi-Buisson N, Haas SA, Hu H, Bienek M, Vissers LELM, Gilissen C, Tzschach A, Busche A, Müsebeck J, Rump P, Mathijssen IB, Avela K, Somer M, Doagu F, Philips AK, Rauch A, Baumer A, Voesenek K, Poirier K, Vigneron J, Amram D, Odent S, Nawara M, Obersztyn E, Lenart J, Charzewska A, Lebrun N, Fischer U, Nillesen WM, Yntema HG, Järvelä I, Ropers HH, de Vries BBA, Brunner HG, van Bokhoven H, Raymond FL, Willemsen MAAP, Chelly J, Xiong Y, Barkovich AJ, Kalscheuer VM, Kleefstra T, de Brouwer APM. Variants in CUL4B are associated with cerebral malformations. Hum Mutat 2015; 36:106-17. [PMID: 25385192 DOI: 10.1002/humu.22718] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 10/17/2014] [Indexed: 11/08/2022]
Abstract
Variants in cullin 4B (CUL4B) are a known cause of syndromic X-linked intellectual disability. Here, we describe an additional 25 patients from 11 families with variants in CUL4B. We identified nine different novel variants in these families and confirmed the pathogenicity of all nontruncating variants. Neuroimaging data, available for 15 patients, showed the presence of cerebral malformations in ten patients. The cerebral anomalies comprised malformations of cortical development (MCD), ventriculomegaly, and diminished white matter volume. The phenotypic heterogeneity of the cerebral malformations might result from the involvement of CUL-4B in various cellular pathways essential for normal brain development. Accordingly, we show that CUL-4B interacts with WDR62, a protein in which variants were previously identified in patients with microcephaly and a wide range of MCD. This interaction might contribute to the development of cerebral malformations in patients with variants in CUL4B.
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Affiliation(s)
- Anneke T Vulto-van Silfhout
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences and Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
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134
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Kodani A, Yu TW, Johnson JR, Jayaraman D, Johnson TL, Al-Gazali L, Sztriha L, Partlow JN, Kim H, Krup AL, Dammermann A, Krogan NJ, Walsh CA, Reiter JF. Centriolar satellites assemble centrosomal microcephaly proteins to recruit CDK2 and promote centriole duplication. eLife 2015; 4:e07519. [PMID: 26297806 PMCID: PMC4574112 DOI: 10.7554/elife.07519] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 08/21/2015] [Indexed: 12/23/2022] Open
Abstract
Primary microcephaly (MCPH) associated proteins CDK5RAP2, CEP152, WDR62 and CEP63 colocalize at the centrosome. We found that they interact to promote centriole duplication and form a hierarchy in which each is required to localize another to the centrosome, with CDK5RAP2 at the apex, and CEP152, WDR62 and CEP63 at sequentially lower positions. MCPH proteins interact with distinct centriolar satellite proteins; CDK5RAP2 interacts with SPAG5 and CEP72, CEP152 with CEP131, WDR62 with MOONRAKER, and CEP63 with CEP90 and CCDC14. These satellite proteins localize their cognate MCPH interactors to centrosomes and also promote centriole duplication. Consistent with a role for satellites in microcephaly, homozygous mutations in one satellite gene, CEP90, may cause MCPH. The satellite proteins, with the exception of CCDC14, and MCPH proteins promote centriole duplication by recruiting CDK2 to the centrosome. Thus, centriolar satellites build a MCPH complex critical for human neurodevelopment that promotes CDK2 centrosomal localization and centriole duplication.
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Affiliation(s)
- Andrew Kodani
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
| | - Timothy W Yu
- Howard Hughes Medical Institute, Boston Children's Hospital, Boston, United States
| | - Jeffrey R Johnson
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
| | - Divya Jayaraman
- Howard Hughes Medical Institute, Boston Children's Hospital, Boston, United States
| | - Tasha L Johnson
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
| | - Lihadh Al-Gazali
- Department of Paediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates
| | - Lāszló Sztriha
- Department of Paediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates
| | - Jennifer N Partlow
- Howard Hughes Medical Institute, Boston Children's Hospital, Boston, United States
| | - Hanjun Kim
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
| | - Alexis L Krup
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
| | | | - Nevan J Krogan
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
| | - Christopher A Walsh
- Howard Hughes Medical Institute, Boston Children's Hospital, Boston, United States
| | - Jeremy F Reiter
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
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135
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Stouffer MA, Golden JA, Francis F. Neuronal migration disorders: Focus on the cytoskeleton and epilepsy. Neurobiol Dis 2015; 92:18-45. [PMID: 26299390 DOI: 10.1016/j.nbd.2015.08.003] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 08/05/2015] [Accepted: 08/12/2015] [Indexed: 01/28/2023] Open
Abstract
A wide spectrum of focal, regional, or diffuse structural brain abnormalities, collectively known as malformations of cortical development (MCDs), frequently manifest with intellectual disability (ID), epilepsy, and/or autistic spectrum disorder (ASD). As the acronym suggests, MCDs are perturbations of the normal architecture of the cerebral cortex and hippocampus. The pathogenesis of these disorders remains incompletely understood; however, one area that has provided important insights has been the study of neuronal migration. The amalgamation of human genetics and experimental studies in animal models has led to the recognition that common genetic causes of neurodevelopmental disorders, including many severe epilepsy syndromes, are due to mutations in genes regulating the migration of newly born post-mitotic neurons. Neuronal migration genes often, though not exclusively, code for proteins involved in the function of the cytoskeleton. Other cellular processes, such as cell division and axon/dendrite formation, which similarly depend on cytoskeletal functions, may also be affected. We focus here on how the susceptibility of the highly organized neocortex and hippocampus may be due to their laminar organization, which involves the tight regulation, both temporally and spatially, of gene expression, specialized progenitor cells, the migration of neurons over large distances and a birthdate-specific layering of neurons. Perturbations in neuronal migration result in abnormal lamination, neuronal differentiation defects, abnormal cellular morphology and circuit formation. Ultimately this results in disorganized excitatory and inhibitory activity leading to the symptoms observed in individuals with these disorders.
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Affiliation(s)
- Melissa A Stouffer
- INSERM UMRS 839, Paris, France; Sorbonne Universités, Université Pierre et Marie Curie, Paris, France; Institut du Fer à Moulin, Paris, France
| | - Jeffrey A Golden
- Department of Pathology, Brigham & Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA
| | - Fiona Francis
- INSERM UMRS 839, Paris, France; Sorbonne Universités, Université Pierre et Marie Curie, Paris, France; Institut du Fer à Moulin, Paris, France.
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136
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David A, Liu F, Tibelius A, Vulprecht J, Wald D, Rothermel U, Ohana R, Seitel A, Metzger J, Ashery-Padan R, Meinzer HP, Gröne HJ, Izraeli S, Krämer A. Lack of centrioles and primary cilia in STIL(-/-) mouse embryos. Cell Cycle 2015; 13:2859-68. [PMID: 25486474 DOI: 10.4161/15384101.2014.946830] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Although most animal cells contain centrosomes, consisting of a pair of centrioles, their precise contribution to cell division and embryonic development is unclear. Genetic ablation of STIL, an essential component of the centriole replication machinery in mammalian cells, causes embryonic lethality in mice around mid gestation associated with defective Hedgehog signaling. Here, we describe, by focused ion beam scanning electron microscopy, that STIL(-/-) mouse embryos do not contain centrioles or primary cilia, suggesting that these organelles are not essential for mammalian development until mid gestation. We further show that the lack of primary cilia explains the absence of Hedgehog signaling in STIL(-/-) cells. Exogenous re-expression of STIL or STIL microcephaly mutants compatible with human survival, induced non-templated, de novo generation of centrioles in STIL(-/-) cells. Thus, while the abscence of centrioles is compatible with mammalian gastrulation, lack of centrioles and primary cilia impairs Hedgehog signaling and further embryonic development.
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Key Words
- CDK6, cyclin-dependent kinase 6
- CEP, centrosomal protein
- COILEDX, coiled-coil domain deletion
- E, embryonic day
- FIB/SEM, focused ion beam scanning electron microscopy
- MCPH, autosomal recessive primary microcephaly
- MEFs, mouse embryonic fibroblasts
- MTOC, microtubule organizing center
- PLK4, polo kinase 4
- SHH, sonic hedgehog
- STAN, STIL/ANA2
- STANX, STAN domain deletion
- STIL
- STIL, SCL/TAL1 interrupting locus
- centriole
- centrosome
- electron microscopy
- embryo
- microcephaly
- nm, nanometer
- siRNA, small interfering RNA
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Affiliation(s)
- Ahuvit David
- a Sheba Cancer Research Center and the Edmond and Lily Safra Children's Hospital; Sheba Medical Center ; Tel-Hashomer, Ramat Gan , Israel
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137
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Jouan L, Ouled Amar Bencheikh B, Daoud H, Dionne-Laporte A, Dobrzeniecka S, Spiegelman D, Rochefort D, Hince P, Szuto A, Lassonde M, Barbelanne M, Tsang WY, Dion PA, Théoret H, Rouleau GA. Exome sequencing identifies recessive CDK5RAP2 variants in patients with isolated agenesis of corpus callosum. Eur J Hum Genet 2015. [PMID: 26197979 DOI: 10.1038/ejhg.2015.156] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Agenesis of the corpus callosum (ACC) is a common brain malformation which can be observed either as an isolated condition or as part of numerous congenital syndromes. Therefore, cognitive and neurological involvements in patients with ACC are variable, from mild linguistic and behavioral impairments to more severe neurological deficits. To date, the underlying genetic causes of isolated ACC remains elusive and causative genes have yet to be identified. We performed exome sequencing on three acallosal siblings from the same non-consanguineous family and identified compound heterozygous variants, p.[Gly94Arg];[Asn1232Ser], in the protein encoded by the CDK5RAP2 gene, also known as MCPH3, a gene previously reported to cause autosomal recessive primary microcephaly. Our findings suggest a novel role for this gene in the pathogenesis of isolated ACC.
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Affiliation(s)
- Loubna Jouan
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montréal, Québec, Canada
| | - Bouchra Ouled Amar Bencheikh
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montréal, Québec, Canada
| | - Hussein Daoud
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montréal, Québec, Canada
| | - Alexandre Dionne-Laporte
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montréal, Québec, Canada
| | - Sylvia Dobrzeniecka
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montréal, Québec, Canada
| | - Dan Spiegelman
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montréal, Québec, Canada
| | - Daniel Rochefort
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montréal, Québec, Canada
| | - Pascale Hince
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montréal, Québec, Canada
| | - Anna Szuto
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montréal, Québec, Canada
| | - Maryse Lassonde
- Department of Psychology, Université de Montréal, Montréal, Québec, Canada.,CHU Sainte-Justine Research Center, Montréal, Québec, Canada
| | - Marine Barbelanne
- Department of Pathology and Cell Biology, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada.,Institut de recherches cliniques de Montréal, Montréal, Québec, Canada
| | - William Y Tsang
- Department of Pathology and Cell Biology, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada.,Institut de recherches cliniques de Montréal, Montréal, Québec, Canada.,Division of Experimental Medicine, McGill University, Montréal, Québec, Canada
| | - Patrick A Dion
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montréal, Québec, Canada.,Department of Pathology and Cell Biology, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Hugo Théoret
- Department of Psychology, Université de Montréal, Montréal, Québec, Canada.,CHU Sainte-Justine Research Center, Montréal, Québec, Canada
| | - Guy A Rouleau
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montréal, Québec, Canada
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138
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Shi L, Lin Q, Su B. Estrogen regulation of microcephaly genes and evolution of brain sexual dimorphism in primates. BMC Evol Biol 2015; 15:127. [PMID: 26123139 PMCID: PMC4487212 DOI: 10.1186/s12862-015-0398-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 05/29/2015] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Sexual dimorphism in brain size is common among primates, including humans, apes and some Old World monkeys. In these species, the brain size of males is generally larger than that of females. Curiously, this dimorphism has persisted over the course of primate evolution and human origin, but there is no explanation for the underlying genetic controls that have maintained this disparity in brain size. RESULTS In the present study, we tested the effect of the female hormone (estradiol) on seven genes known to be related to brain size in both humans and nonhuman primates, and we identified half estrogen responsive elements (half EREs) in the promoter regions of four genes (MCPH1, ASPM, CDK5RAP2 and WDR62). Likewise, at sequence level, it appears that these half EREs are generally conserved across primates. Later testing via a reporter gene assay and cell-based endogenous expression measurement revealed that estradiol could significantly suppress the expression of the four affected genes involved in brain size. More intriguingly, when the half EREs were deleted from the promoters, the suppression effect disappeared, suggesting that the half EREs mediate the regulation of estradiol on the brain size genes. We next replicated these experiments using promoter sequences from chimpanzees and rhesus macaques, and observed a similar suppressive effect of estradiol on gene expression, suggesting that this mechanism is conserved among primate species that exhibit brain size dimorphism. CONCLUSIONS Brain size dimorphism among certain primates, including humans, is likely regulated by estrogen through its sex-dependent suppression of brain size genes during development.
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Affiliation(s)
- Lei Shi
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, 32 East Jiao-Chang Road, Kunming, 650223, Yunnan, PR China. .,Yunnan Key Laboratory of Primate Biomedical Research, Kunming, 650000, China.
| | - Qiang Lin
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, 32 East Jiao-Chang Road, Kunming, 650223, Yunnan, PR China. .,Yunnan Key Laboratory of Primate Biomedical Research, Kunming, 650000, China. .,Kunming College of Life Science, University of Chinese Academy of Sciences, Beijing, 100101, China.
| | - Bing Su
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, 32 East Jiao-Chang Road, Kunming, 650223, Yunnan, PR China. .,Yunnan Key Laboratory of Primate Biomedical Research, Kunming, 650000, China.
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139
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Lim JS, Lee JH. Molecular genetic decoding of malformations of cortical development. ACTA ACUST UNITED AC 2015. [DOI: 10.5734/jgm.2015.12.1.12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Jae Seok Lim
- Graduate School of Medical Science and Engineering, KAIST, Daejeon, Korea
| | - Jeong Ho Lee
- Graduate School of Medical Science and Engineering, KAIST, Daejeon, Korea
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140
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Jinks RN, Puffenberger EG, Baple E, Harding B, Crino P, Fogo AB, Wenger O, Xin B, Koehler AE, McGlincy MH, Provencher MM, Smith JD, Tran L, Al Turki S, Chioza BA, Cross H, Harlalka GV, Hurles ME, Maroofian R, Heaps AD, Morton MC, Stempak L, Hildebrandt F, Sadowski CE, Zaritsky J, Campellone K, Morton DH, Wang H, Crosby A, Strauss KA. Recessive nephrocerebellar syndrome on the Galloway-Mowat syndrome spectrum is caused by homozygous protein-truncating mutations of WDR73. Brain 2015; 138:2173-90. [PMID: 26070982 PMCID: PMC4511861 DOI: 10.1093/brain/awv153] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 04/14/2015] [Indexed: 12/20/2022] Open
Abstract
Galloway-Mowat syndrome (GMS) is a neurodevelopmental disorder characterized by microcephaly, cerebellar hypoplasia, nephrosis, and profound intellectual disability. Jinks et al. extend the GMS spectrum by identifying a novel nephrocerebellar syndrome with selective striatal cholinergic interneuron loss and complete lateral geniculate nucleus delamination, caused by a frameshift mutation in WDR73. We describe a novel nephrocerebellar syndrome on the Galloway-Mowat syndrome spectrum among 30 children (ages 1.0 to 28 years) from diverse Amish demes. Children with nephrocerebellar syndrome had progressive microcephaly, visual impairment, stagnant psychomotor development, abnormal extrapyramidal movements and nephrosis. Fourteen died between ages 2.7 and 28 years, typically from renal failure. Post-mortem studies revealed (i) micrencephaly without polymicrogyria or heterotopia; (ii) atrophic cerebellar hemispheres with stunted folia, profound granule cell depletion, Bergmann gliosis, and signs of Purkinje cell deafferentation; (iii) selective striatal cholinergic interneuron loss; and (iv) optic atrophy with delamination of the lateral geniculate nuclei. Renal tissue showed focal and segmental glomerulosclerosis and extensive effacement and microvillus transformation of podocyte foot processes. Nephrocerebellar syndrome mapped to 700 kb on chromosome 15, which contained a single novel homozygous frameshift variant (WDR73 c.888delT; p.Phe296Leufs*26). WDR73 protein is expressed in human cerebral cortex, hippocampus, and cultured embryonic kidney cells. It is concentrated at mitotic microtubules and interacts with α-, β-, and γ-tubulin, heat shock proteins 70 and 90 (HSP-70; HSP-90), and the carbamoyl phosphate synthetase 2/aspartate transcarbamylase/dihydroorotase multi-enzyme complex. Recombinant WDR73 p.Phe296Leufs*26 and p.Arg256Profs*18 proteins are truncated, unstable, and show increased interaction with α- and β-tubulin and HSP-70/HSP-90. Fibroblasts from patients homozygous for WDR73 p.Phe296Leufs*26 proliferate poorly in primary culture and senesce early. Our data suggest that in humans, WDR73 interacts with mitotic microtubules to regulate cell cycle progression, proliferation and survival in brain and kidney. We extend the Galloway-Mowat syndrome spectrum with the first description of diencephalic and striatal neuropathology.
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Affiliation(s)
- Robert N Jinks
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA
| | - Erik G Puffenberger
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA 2 Clinic for Special Children, Strasburg, PA 17579, USA
| | - Emma Baple
- 3 RILD Wellcome Wolfson Centre, Royal Devon and Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK 4 Human Genetics and Genomic Medicine, Faculty of Medicine, University of Southampton, UK 5 Wessex Clinical Genetics Service, Princess Anne Hospital, Southampton, UK
| | - Brian Harding
- 6 Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia and Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Peter Crino
- 7 Shriners Hospital Paediatric Research Centre, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Agnes B Fogo
- 8 Division of Renal Pathology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Olivia Wenger
- 9 New Leaf Clinic for Special Children, Mount Eaton, OH 44659, USA 10 Department of Paediatrics, Akron Children's Hospital, Akron, OH 44302, USA
| | - Baozhong Xin
- 11 DDC Clinic for Special Needs Children, Middlefield, OH 44062, USA
| | - Alanna E Koehler
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA
| | - Madeleine H McGlincy
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA
| | - Margaret M Provencher
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA
| | - Jeffrey D Smith
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA
| | - Linh Tran
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA
| | - Saeed Al Turki
- 12 Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Barry A Chioza
- 13 Medical Research, RILD Wellcome Wolfson Centre, University of Exeter Medical School, Exeter EX1 2LU, UK
| | - Harold Cross
- 14 Department of Ophthalmology, University of Arizona College of Medicine, Tucson, AZ 85711, USA
| | - Gaurav V Harlalka
- 13 Medical Research, RILD Wellcome Wolfson Centre, University of Exeter Medical School, Exeter EX1 2LU, UK
| | - Matthew E Hurles
- 12 Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Reza Maroofian
- 13 Medical Research, RILD Wellcome Wolfson Centre, University of Exeter Medical School, Exeter EX1 2LU, UK
| | - Adam D Heaps
- 2 Clinic for Special Children, Strasburg, PA 17579, USA
| | - Mary C Morton
- 2 Clinic for Special Children, Strasburg, PA 17579, USA
| | - Lisa Stempak
- 15 Department of Pathology, University Hospitals Case Medical Centre, Cleveland, OH 44106, USA 16 Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Friedhelm Hildebrandt
- 17 Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA 18 Division of Nephrology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Carolin E Sadowski
- 18 Division of Nephrology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Joshua Zaritsky
- 19 Department of Paediatrics, Nemours/Alfred I. DuPont Hospital for Children, Wilmington, DE 19803, USA
| | - Kenneth Campellone
- 20 Department of Molecular and Cell Biology and Institute for Systems Genomics, University of Connecticut, Storrs, CT 06269, USA
| | - D Holmes Morton
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA 2 Clinic for Special Children, Strasburg, PA 17579, USA 21 Lancaster General Hospital, Lancaster, PA 17602, USA
| | - Heng Wang
- 11 DDC Clinic for Special Needs Children, Middlefield, OH 44062, USA 22 Department of Paediatrics, Rainbow Babies and Children's Hospital and Department of Molecular Cardiology, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Andrew Crosby
- 3 RILD Wellcome Wolfson Centre, Royal Devon and Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK
| | - Kevin A Strauss
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA 2 Clinic for Special Children, Strasburg, PA 17579, USA 21 Lancaster General Hospital, Lancaster, PA 17602, USA
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141
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Morris-Rosendahl DJ, Kaindl AM. What next-generation sequencing (NGS) technology has enabled us to learn about primary autosomal recessive microcephaly (MCPH). Mol Cell Probes 2015; 29:271-81. [PMID: 26050940 DOI: 10.1016/j.mcp.2015.05.015] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 05/28/2015] [Accepted: 05/29/2015] [Indexed: 11/27/2022]
Abstract
The impact that next-generation sequencing technology (NGS) is having on many aspects of molecular and cell biology, is becoming increasingly apparent. One of the most noticeable outcomes of the new technology in human genetics, has been the accelerated rate of identification of disease-causing genes. Especially for rare, heterogeneous disorders, such as autosomal recessive primary microcephaly (MCPH), the handful of genes previously known to harbour disease-causing mutations, has grown at an unprecedented rate within a few years. Knowledge of new genes mutated in MCPH over the last four years has contributed to our understanding of the disorder at both the clinical and cellular levels. The functions of proteins such as WDR62, CASC5, PHC1, CDK6, CENP-E, CENP-F, CEP63, ZNF335, PLK4 and TUBGPC, have been added to the complex network of critical cellular processes known to be involved in brain growth and size. In addition to the importance of mitotic spindle assembly and structure, centrosome and centriole function and DNA repair and damage response, new mechanisms involving kinetochore-associated proteins and chromatin remodelling complexes have been elucidated. Two of the major contributions to our clinical knowledge are the realisation that primary microcephaly caused by mutations in genes at the MCPH loci is seldom an isolated clinical feature and is often accompanied either by additional cortical malformations or primordial dwarfism. Gene-phenotype correlations are being revisited, with a new dimension of locus heterogeneity and phenotypic variability being revealed.
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Affiliation(s)
- Deborah J Morris-Rosendahl
- Clinical Genetics and Genomics, Royal Brompton and Harefield NHS Foundation Trust, London, United Kingdom; National Heart and Lung Institute, Imperial College London, London, United Kingdom.
| | - Angela M Kaindl
- Department of Pediatric Neurology, Charité University Medicine, Berlin, Germany; Institute of Cell Biology and Neurobiology, Charité University Medicine, Berlin, Germany
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142
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Abstract
Malformations of cortical development (MCDs) are a common cause of neurodevelopmental delay and epilepsy and are caused by disruptions in the normal development of the cerebral cortex. Several causative genes have been identified in patients with MCD. There is increasing evidence of role of de novo mutations, including those occurring post fertilization, in MCD. These somatic mutations may not be detectable by traditional methods of genetic testing performed on blood DNA. Identification of the genetic cause can help in guiding families in future pregnancies. Research has highlighted how elucidation of key molecular pathways can also allow for targeted therapeutic interventions.
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Affiliation(s)
- Saumya S Jamuar
- Department of Paediatrics, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore 229899, Singapore; Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, Boston, MA 02115, USA; Paediatrics Academic Programme, Duke-NUS Graduate Medical School, 8 College Road, Singapore 169857, Singapore
| | - Christopher A Walsh
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, Boston, MA 02115, USA; Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02138, USA.
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143
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Nakayama T, Al-Maawali A, El-Quessny M, Rajab A, Khalil S, Stoler JM, Tan WH, Nasir R, Schmitz-Abe K, Hill RS, Partlow JN, Al-Saffar M, Servattalab S, LaCoursiere CM, Tambunan DE, Coulter ME, Elhosary PC, Gorski G, Barkovich AJ, Markianos K, Poduri A, Mochida GH. Mutations in PYCR2, Encoding Pyrroline-5-Carboxylate Reductase 2, Cause Microcephaly and Hypomyelination. Am J Hum Genet 2015; 96:709-19. [PMID: 25865492 PMCID: PMC4570282 DOI: 10.1016/j.ajhg.2015.03.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Accepted: 03/05/2015] [Indexed: 12/27/2022] Open
Abstract
Despite recent advances in understanding the genetic bases of microcephaly, a large number of cases of microcephaly remain unexplained, suggesting that many microcephaly syndromes and associated genes have yet to be identified. Here, we report mutations in PYCR2, which encodes an enzyme in the proline biosynthesis pathway, as the cause of a unique syndrome characterized by postnatal microcephaly, hypomyelination, and reduced cerebral white-matter volume. Linkage mapping and whole-exome sequencing identified homozygous mutations (c.355C>T [p.Arg119Cys] and c.751C>T [p.Arg251Cys]) in PYCR2 in the affected individuals of two consanguineous families. A lymphoblastoid cell line from one affected individual showed a strong reduction in the amount of PYCR2. When mutant cDNAs were transfected into HEK293FT cells, both variant proteins retained normal mitochondrial localization but had lower amounts than the wild-type protein, suggesting that the variant proteins were less stable. A PYCR2-deficient HEK293FT cell line generated by genome editing with the clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9 system showed that PYCR2 loss of function led to decreased mitochondrial membrane potential and increased susceptibility to apoptosis under oxidative stress. Morpholino-based knockdown of a zebrafish PYCR2 ortholog, pycr1b, recapitulated the human microcephaly phenotype, which was rescued by wild-type human PYCR2 mRNA, but not by mutant mRNAs, further supporting the pathogenicity of the identified variants. Hypomyelination and the absence of lax, wrinkly skin distinguishes this condition from that caused by previously reported mutations in the gene encoding PYCR2's isozyme, PYCR1, suggesting a unique and indispensable role for PYCR2 in the human CNS during development.
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Affiliation(s)
- Tojo Nakayama
- Division of Genetics and Genomics, Department of Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA
| | - Almundher Al-Maawali
- Division of Genetics and Genomics, Department of Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Department of Genetics, College of Medicine and Health Science, Sultan Qaboos University, Muscat 123, Oman
| | - Malak El-Quessny
- Division of Genetics and Genomics, Department of Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA
| | - Anna Rajab
- National Genetics Center, Directorate General of Health Affairs, Ministry of Health, Muscat 113, Oman
| | - Samir Khalil
- Department of Pediatrics, Al-Makassed Islamic Charitable Society Hospital, Jerusalem 91220; Faculty of Medicine, Al-Quds University, Jerusalem 90612
| | - Joan M Stoler
- Division of Genetics and Genomics, Department of Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA
| | - Wen-Hann Tan
- Division of Genetics and Genomics, Department of Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA
| | - Ramzi Nasir
- Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Division of Developmental Medicine, Department of Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Klaus Schmitz-Abe
- Division of Genetics and Genomics, Department of Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - R Sean Hill
- Division of Genetics and Genomics, Department of Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA 02115, USA
| | - Jennifer N Partlow
- Division of Genetics and Genomics, Department of Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA 02115, USA
| | - Muna Al-Saffar
- Division of Genetics and Genomics, Department of Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA 02115, USA; Department of Paediatrics, College of Medicine and Health Sciences, United Arab Emirates University, PO Box 17666, Al-Ain, United Arab Emirates
| | - Sarah Servattalab
- Division of Genetics and Genomics, Department of Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA 02115, USA
| | | | - Dimira E Tambunan
- Department of Neurology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Michael E Coulter
- Division of Genetics and Genomics, Department of Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA 02115, USA; Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA 02139, USA
| | - Princess C Elhosary
- Division of Genetics and Genomics, Department of Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Grzegorz Gorski
- Cellular Neuroscience Core, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA
| | - A James Barkovich
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Kyriacos Markianos
- Division of Genetics and Genomics, Department of Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Annapurna Poduri
- Department of Neurology, Boston Children's Hospital, Boston, MA 02115, USA; Epilepsy Genetics Program, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Ganeshwaran H Mochida
- Division of Genetics and Genomics, Department of Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Pediatric Neurology Unit, Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA.
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144
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Abstract
The development and function of our brain are governed by a genetic blueprint, which reflects dynamic changes over the history of evolution. Recent progress in genetics and genomics, facilitated by next-generation sequencing and single-cell sorting, has identified numerous genomic loci that are associated with a neuroanatomical or neurobehavioral phenotype. Here, we review some of the genetic changes in both protein-coding and noncoding regions that affect brain development and evolution, as well as recent progress in brain transcriptomics. Understanding these genetic changes may provide novel insights into neurological and neuropsychiatric disorders, such as autism and schizophrenia.
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Affiliation(s)
- Byoung-Il Bae
- Division of Genetics and Genomics, Manton Center for Orphan Disease, and Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Boston, MA 02115, USA; and Departments of Pediatrics and Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Divya Jayaraman
- Division of Genetics and Genomics, Manton Center for Orphan Disease, and Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Boston, MA 02115, USA; and Departments of Pediatrics and Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Christopher A Walsh
- Division of Genetics and Genomics, Manton Center for Orphan Disease, and Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Boston, MA 02115, USA; and Departments of Pediatrics and Neurology, Harvard Medical School, Boston, MA 02115, USA.
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145
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Bizzotto S, Francis F. Morphological and functional aspects of progenitors perturbed in cortical malformations. Front Cell Neurosci 2015; 9:30. [PMID: 25729350 PMCID: PMC4325918 DOI: 10.3389/fncel.2015.00030] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Accepted: 01/18/2015] [Indexed: 11/13/2022] Open
Abstract
In this review, we discuss molecular and cellular mechanisms important for the function of neuronal progenitors during development, revealed by their perturbation in different cortical malformations. We focus on a class of neuronal progenitors, radial glial cells (RGCs), which are renowned for their unique morphological and behavioral characteristics, constituting a key element during the development of the mammalian cerebral cortex. We describe how the particular morphology of these cells is related to their roles in the orchestration of cortical development and their influence on other progenitor types and post-mitotic neurons. Important for disease mechanisms, we overview what is currently known about RGC cellular components, cytoskeletal mechanisms, signaling pathways and cell cycle characteristics, focusing on how defects lead to abnormal development and cortical malformation phenotypes. The multiple recent entry points from human genetics and animal models are contributing to our understanding of this important cell type. Combining data from phenotypes in the mouse reveals molecules which potentially act in common pathways. Going beyond this, we discuss future directions that may provide new data in this expanding area.
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Affiliation(s)
- Sara Bizzotto
- INSERM UMRS 839 Paris, France ; Sorbonne Universités, Université Pierre et Marie Curie Paris, France ; Institut du Fer à Moulin Paris, France
| | - Fiona Francis
- INSERM UMRS 839 Paris, France ; Sorbonne Universités, Université Pierre et Marie Curie Paris, France ; Institut du Fer à Moulin Paris, France
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146
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Faheem M, Naseer MI, Rasool M, Chaudhary AG, Kumosani TA, Ilyas AM, Pushparaj P, Ahmed F, Algahtani HA, Al-Qahtani MH, Saleh Jamal H. Molecular genetics of human primary microcephaly: an overview. BMC Med Genomics 2015; 8 Suppl 1:S4. [PMID: 25951892 PMCID: PMC4315316 DOI: 10.1186/1755-8794-8-s1-s4] [Citation(s) in RCA: 154] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Autosomal recessive primary microcephaly (MCPH) is a neurodevelopmental disorder that is characterised by microcephaly present at birth and non-progressive mental retardation. Microcephaly is the outcome of a smaller but architecturally normal brain; the cerebral cortex exhibits a significant decrease in size. MCPH is a neurogenic mitotic disorder, though affected patients demonstrate normal neuronal migration, neuronal apoptosis and neural function. Twelve MCPH loci (MCPH1-MCPH12) have been mapped to date from various populations around the world and contain the following genes: Microcephalin, WDR62, CDK5RAP2, CASC5, ASPM, CENPJ, STIL, CEP135, CEP152, ZNF335, PHC1 and CDK6. It is predicted that MCPH gene mutations may lead to the disease phenotype due to a disturbed mitotic spindle orientation, premature chromosomal condensation, signalling response as a result of damaged DNA, microtubule dynamics, transcriptional control or a few other hidden centrosomal mechanisms that can regulate the number of neurons produced by neuronal precursor cells. Additional findings have further elucidated the microcephaly aetiology and pathophysiology, which has informed the clinical management of families suffering from MCPH. The provision of molecular diagnosis and genetic counselling may help to decrease the frequency of this disorder.
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147
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Molecular and cellular basis of autosomal recessive primary microcephaly. BIOMED RESEARCH INTERNATIONAL 2014; 2014:547986. [PMID: 25548773 PMCID: PMC4274849 DOI: 10.1155/2014/547986] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 09/18/2014] [Accepted: 09/18/2014] [Indexed: 01/23/2023]
Abstract
Autosomal recessive primary microcephaly (MCPH) is a rare hereditary neurodevelopmental disorder characterized by a marked reduction in brain size and intellectual disability. MCPH is genetically heterogeneous and can exhibit additional clinical features that overlap with related disorders including Seckel syndrome, Meier-Gorlin syndrome, and microcephalic osteodysplastic dwarfism. In this review, we discuss the key proteins mutated in MCPH. To date, MCPH-causing mutations have been identified in twelve different genes, many of which encode proteins that are involved in cell cycle regulation or are present at the centrosome, an organelle crucial for mitotic spindle assembly and cell division. We highlight recent findings on MCPH proteins with regard to their role in cell cycle progression, centrosome function, and early brain development.
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Colin E, Huynh Cong E, Mollet G, Guichet A, Gribouval O, Arrondel C, Boyer O, Daniel L, Gubler MC, Ekinci Z, Tsimaratos M, Chabrol B, Boddaert N, Verloes A, Chevrollier A, Gueguen N, Desquiret-Dumas V, Ferré M, Procaccio V, Richard L, Funalot B, Moncla A, Bonneau D, Antignac C. Loss-of-function mutations in WDR73 are responsible for microcephaly and steroid-resistant nephrotic syndrome: Galloway-Mowat syndrome. Am J Hum Genet 2014; 95:637-48. [PMID: 25466283 DOI: 10.1016/j.ajhg.2014.10.011] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 10/24/2014] [Indexed: 01/08/2023] Open
Abstract
Galloway-Mowat syndrome is a rare autosomal-recessive condition characterized by nephrotic syndrome associated with microcephaly and neurological impairment. Through a combination of autozygosity mapping and whole-exome sequencing, we identified WDR73 as a gene in which mutations cause Galloway-Mowat syndrome in two unrelated families. WDR73 encodes a WD40-repeat-containing protein of unknown function. Here, we show that WDR73 was present in the brain and kidney and was located diffusely in the cytoplasm during interphase but relocalized to spindle poles and astral microtubules during mitosis. Fibroblasts from one affected child and WDR73-depleted podocytes displayed abnormal nuclear morphology, low cell viability, and alterations of the microtubule network. These data suggest that WDR73 plays a crucial role in the maintenance of cell architecture and cell survival. Altogether, WDR73 mutations cause Galloway-Mowat syndrome in a particular subset of individuals presenting with late-onset nephrotic syndrome, postnatal microcephaly, severe intellectual disability, and homogenous brain MRI features. WDR73 is another example of a gene involved in a disease affecting both the kidney glomerulus and the CNS.
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Rupp V, Rauf S, Naveed I, Windpassinger C, Mir A. A novel single base pair duplication in WDR62 causes primary microcephaly. BMC MEDICAL GENETICS 2014; 15:107. [PMID: 25303973 PMCID: PMC4258795 DOI: 10.1186/s12881-014-0107-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 09/10/2014] [Indexed: 12/19/2022]
Abstract
BACKGROUND Primary microcephaly is a disorder of the brain resulting in a reduced head circumference that can come along with intellectual disability but with hardly any other neurological abnormalities. CASE PRESENTATION In this study we report on three Pakistani males from a consanguineous family with 2, 4 and 25 years, diagnosed with autosomal recessive primary microcephaly. By genotyping, Sanger sequencing and using bioinformatical approaches the disease causing mutation was identified and evaluated. CONCLUSION By using a 250K SNP array, we were able to detect an 11Mb large autozygous region in the MCPH2 locus on chromosome 19q13.12. Sequencing of the associated gene, WDR62, revealed the frameshift causing single base pair duplication, c.2527dupG. This mutation is predicted to affect the structural features of WDR62 which in turn changes the conformation and function of the protein. Aspartic acid (D) at position 843 was found to be conserved among various ortholog species. The present findings will be helpful in genetic diagnosis of patients and future studies of WDR62.
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Abstract
In the past few years, the increasing accessibility of next-generation sequencing technology has translated to a number of significant advances in our understanding of brain malformations. Genes causing brain malformations, previously intractable due to their complex presentation, rarity, sporadic occurrence, or molecular mechanism, are being identified at an unprecedented rate and are revealing important insights into central nervous system development. Recent discoveries highlight new associations of biological processes with human disease including the PI3K-AKT-mTOR pathway in brain overgrowth syndromes, the trafficking of cellular proteins in microcephaly-capillary malformation syndrome, and the role of the exosome in the etiology of pontocerebellar hypoplasia. Several other gene discoveries expand our understanding of the role of mitosis in the primary microcephaly syndromes and post-translational modification of dystroglycan in lissencephaly. Insights into polymicrogyria and heterotopias show us that these 2 malformations are complex in their etiology, while recent work in holoprosencephaly and Dandy-Walker malformation suggest that, at least in some instances, the development of these malformations requires "multiple-hits" in the sonic hedgehog pathway. The discovery of additional genes for primary microcephaly, pontocerebellar hypoplasia, and spinocerebellar ataxia continue to impress upon us the significant degree of genetic heterogeneity associated with many brain malformations. It is becoming increasingly evident that next-generation sequencing is emerging as a tool to facilitate rapid and cost-effective molecular diagnoses that will be translated into routine clinical care for these rare conditions in the near future.
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