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Gras M, Heide S, Keren B, Valence S, Garel C, Whalen S, Jansen AC, Keymolen K, Stouffs K, Jennesson M, Poirsier C, Lesca G, Depienne C, Nava C, Rastetter A, Curie A, Cuisset L, Des Portes V, Milh M, Charles P, Mignot C, Héron D. Further characterisation of ARX-related disorders in females due to inherited or de novo variants. J Med Genet 2024; 61:103-108. [PMID: 37879892 DOI: 10.1136/jmg-2023-109203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 09/30/2023] [Indexed: 10/27/2023]
Abstract
The Aristaless-related homeobox (ARX) gene is located on the X chromosome and encodes a transcription factor that is essential for brain development. While the clinical spectrum of ARX-related disorders is well described in males, from X linked lissencephaly with abnormal genitalia syndrome to syndromic and non-syndromic intellectual disability (ID), its phenotypic delineation in females is incomplete. Carrier females in ARX families are usually asymptomatic, but ID has been reported in some of them, as well as in others with de novo variants. In this study, we collected the clinical and molecular data of 10 unpublished female patients with de novo ARX pathogenic variants and reviewed the data of 63 females from the literature with either de novo variants (n=10), inherited variants (n=33) or variants of unknown inheritance (n=20). Altogether, the clinical spectrum of females with heterozygous pathogenic ARX variants is broad: 42.5% are asymptomatic, 16.4% have isolated agenesis of the corpus callosum (ACC) or mild symptoms (learning disabilities, autism spectrum disorder, drug-responsive epilepsy) without ID, whereas 41% present with a severe phenotype (ie, ID or developmental and epileptic encephalopathy (DEE)). The ID/DEE phenotype was significantly more prevalent in females carrying de novo variants (75%, n=15/20) versus in those carrying inherited variants (27.3%, n=9/33). ACC was observed in 66.7% (n=24/36) of females who underwent a brain MRI. By refining the clinical spectrum of females carrying ARX pathogenic variants, we show that ID is a frequent sign in females with this X linked condition.
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Affiliation(s)
- Mathilde Gras
- Department of Clinical Genetics, APHP Sorbonne Université, University Hospital Pitié Salpêtrière, Paris, France
| | - Solveig Heide
- Department of Clinical Genetics, APHP Sorbonne Université, University Hospital Pitié Salpêtrière, Paris, France
- Reference Center for Rare Diseases « Intellectual disabilities of rare causes » Déficiences Intellectuelles de Causes Rares, University Hospital Pitié Salpêtrière, Paris, France
- Doctoral College, Sorbonne University, Paris, France
| | - Boris Keren
- Department of Clinical Genetics, APHP Sorbonne Université, University Hospital Pitié Salpêtrière, Paris, France
| | - Stéphanie Valence
- Unit of Pediatric Neurology, APHP Sorbonne Université, Armand-Trousseau Hospital, Paris, France
- Reference Center for Rare Diseases « Intellectual disabilites of rare causes » Déficiences Intellectuelles de Causes Rares, Armand-Trousseau Hospital, Paris, France
| | - Catherine Garel
- Unit of Pediatric Radiology, APHP Sorbonne Université, Armand-Trousseau Hospital, Paris, France
| | - Sandra Whalen
- Department of Clinical Genetics and Reference Center for Rare Diseases « Developmental disorders and syndromes », APHP Sorbonne Université, Armand-Trousseau Hospital, Paris, France
| | - Anna C Jansen
- Neurogenetics Research Group, Vrije Universiteit Brussel, Brussels, Belgium
| | - Kathelijn Keymolen
- Clinical Sciences, Research Group Reproduction and Genetics, Centre for Medical Genetics, Universitair Ziekenhuis Brussel (UZ Brussels), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Katrien Stouffs
- Clinical Sciences, Research Group Reproduction and Genetics, Centre for Medical Genetics, Universitair Ziekenhuis Brussel (UZ Brussels), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Mélanie Jennesson
- Pediatrics Unit, University Hospital of Reims, American Memorial Hospital, Reims, France
| | - Céline Poirsier
- UF génétique clinique, Pôle Femme-Parents-Enfants, CHU Reims, Reims, France
| | - Gaetan Lesca
- Department of Genetics, Referral Center for Developmental Anomalies and Malformative Syndromes, Centre-est HCL, Hospices Civils de Lyon, Lyon, France
| | - Christel Depienne
- Institute of Human Genetics, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | | | | | - Aurore Curie
- Reference Centre for Rare Diseases « Intellectual disabilities of rare causes », Civil Hospices of Lyon, Lyon, France
- University Lyon 1 Faculty of Medicine Lyon-Est, Lyon, France
| | - Laurence Cuisset
- APHP Centre Université Paris Cité, Service de Médecine Génomique des Maladies de Système et d'Organe, Cochin Hospital, Paris, France
| | - Vincent Des Portes
- Reference Centre for Rare Diseases « Intellectual disabilities of rare causes », Civil Hospices of Lyon, Lyon, France
- University Lyon 1 Faculty of Medicine Lyon-Est, Lyon, France
| | - Mathieu Milh
- Department of Neurology Pediatrics, AP-HM, Hôpital de la Timone, Marseille, France
| | - Perrine Charles
- Department of Clinical Genetics, APHP Sorbonne Université, University Hospital Pitié Salpêtrière, Paris, France
- Reference Center for Rare Diseases « Intellectual disabilities of rare causes » Déficiences Intellectuelles de Causes Rares, University Hospital Pitié Salpêtrière, Paris, France
| | - Cyril Mignot
- Department of Clinical Genetics, APHP Sorbonne Université, University Hospital Pitié Salpêtrière, Paris, France
- Reference Center for Rare Diseases « Intellectual disabilities of rare causes » Déficiences Intellectuelles de Causes Rares, University Hospital Pitié Salpêtrière, Paris, France
| | - Delphine Héron
- Department of Clinical Genetics, APHP Sorbonne Université, University Hospital Pitié Salpêtrière, Paris, France
- Reference Center for Rare Diseases « Intellectual disabilities of rare causes » Déficiences Intellectuelles de Causes Rares, University Hospital Pitié Salpêtrière, Paris, France
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Poeta L, Padula A, Lioi MB, van Bokhoven H, Miano MG. Analysis of a Set of KDM5C Regulatory Genes Mutated in Neurodevelopmental Disorders Identifies Temporal Coexpression Brain Signatures. Genes (Basel) 2021; 12:genes12071088. [PMID: 34356104 PMCID: PMC8305412 DOI: 10.3390/genes12071088] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/13/2021] [Accepted: 07/15/2021] [Indexed: 12/22/2022] Open
Abstract
Dysregulation of transcriptional pathways is observed in multiple forms of neurodevelopmental disorders (NDDs), such as intellectual disability (ID), epilepsy and autism spectrum disorder (ASD). We previously demonstrated that the NDD genes encoding lysine-specific demethylase 5C (KDM5C) and its transcriptional regulators Aristaless related-homeobox (ARX), PHD Finger Protein 8 (PHF8) and Zinc Finger Protein 711 (ZNF711) are functionally connected. Here, we show their relation to each other with respect to the expression levels in human and mouse datasets and in vivo mouse analysis indicating that the coexpression of these syntenic X-chromosomal genes is temporally regulated in brain areas and cellular sub-types. In co-immunoprecipitation assays, we found that the homeotic transcription factor ARX interacts with the histone demethylase PHF8, indicating that this transcriptional axis is highly intersected. Furthermore, the functional impact of pathogenic mutations of ARX, KDM5C, PHF8 and ZNF711 was tested in lymphoblastoid cell lines (LCLs) derived from children with varying levels of syndromic ID establishing the direct correlation between defects in the KDM5C-H3K4me3 pathway and ID severity. These findings reveal novel insights into epigenetic processes underpinning NDD pathogenesis and provide new avenues for assessing developmental timing and critical windows for potential treatments.
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Affiliation(s)
- Loredana Poeta
- Institute of Genetics and Biophysics Adriano Buzzati-Traverso, CNR, 80131 Naples, Italy;
- Department of Science, University of Basilicata, 85100 Potenza, Italy;
- Correspondence: (L.P.); (M.G.M.); Tel.: +39-(0)-816132261/445 (M.G.M.)
| | - Agnese Padula
- Institute of Genetics and Biophysics Adriano Buzzati-Traverso, CNR, 80131 Naples, Italy;
| | | | - Hans van Bokhoven
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboudumc, 6525 GA Nijmegen, The Netherlands;
| | - Maria Giuseppina Miano
- Institute of Genetics and Biophysics Adriano Buzzati-Traverso, CNR, 80131 Naples, Italy;
- Correspondence: (L.P.); (M.G.M.); Tel.: +39-(0)-816132261/445 (M.G.M.)
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Benmakhlouf Y, Touraine R, Harzallah I, Zian Z, Ben Makhlouf K, Barakat A, Ghailani Nourouti N, Bennani Mechita M. Screening of the duplication 24 pb of ARX gene in Moroccan patients with X-linked Intellectual Disability. BMC Res Notes 2021; 14:110. [PMID: 33757564 PMCID: PMC7988900 DOI: 10.1186/s13104-021-05526-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 03/13/2021] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE Intellectual Disability (ID) represents a neuropsychiatric disorder, which its etiopathogenesis remains insufficiently understood. Mutations in the Aristaless Related Homeobox gene (ARX) have been identified to cause syndromic and nonsyndromic (NS-ID). The most recurrent mutation of this gene is a duplication of 24pb, c.428-451dup. Epidemiological and genetic studies about ID in the Moroccan population remain very scarce, and none study is carried out on the ARX gene. This work aimed to study c.428-451dup (24 bp) mutation in the exon 2 of the ARX gene in 118 males' Moroccan patients with milder NS-ID to evaluate if the gene screening is a good tool for identifying NS-ID. RESULTS Our mutational analysis did not show any dup(24pb) in our patients. This is because based on findings from previous studies that found ARX mutations in 70% of families with NS-ID, and in most cases, 1.5-6.1% of individuals with NS-ID have this duplication. Since 1/118 = 0.0084 (0.84%) is not much different from 1.5%, then it is reasonable that this could a sample size artifact. A complete screening of the entire ARX gene, including the five exons, should be fulfilled. Further investigations are required to confirm these results.
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Affiliation(s)
- Yousra Benmakhlouf
- Biomedical Genomics and Oncogenetics Research Laboratory, Faculty of Sciences and Techniques of Tangier, University Abdelmalek Essaadi, P.B.:416, Tangier, Morocco.
| | | | - Ines Harzallah
- Molecular Genetics Laboratory, CHU, Saint Etienne, France
| | - Zeineb Zian
- Biomedical Genomics and Oncogenetics Research Laboratory, Faculty of Sciences and Techniques of Tangier, University Abdelmalek Essaadi, P.B.:416, Tangier, Morocco
| | | | - Amina Barakat
- Biomedical Genomics and Oncogenetics Research Laboratory, Faculty of Sciences and Techniques of Tangier, University Abdelmalek Essaadi, P.B.:416, Tangier, Morocco
| | - Naima Ghailani Nourouti
- Biomedical Genomics and Oncogenetics Research Laboratory, Faculty of Sciences and Techniques of Tangier, University Abdelmalek Essaadi, P.B.:416, Tangier, Morocco
| | - Mohcine Bennani Mechita
- Biomedical Genomics and Oncogenetics Research Laboratory, Faculty of Sciences and Techniques of Tangier, University Abdelmalek Essaadi, P.B.:416, Tangier, Morocco
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Wu Y, Zhang H, Liu X, Shi Z, Li H, Wang Z, Jie X, Huang S, Zhang F, Li J, Zhang K, Gao X. Mutations of ARX and non-syndromic intellectual disability in Chinese population. Genes Genomics 2018; 41:125-131. [PMID: 30255221 DOI: 10.1007/s13258-018-0745-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 09/15/2018] [Indexed: 02/08/2023]
Abstract
Mutations of Aristaless-related homeobox (ARX) gene were looked as the third cause of non-syndromic intellectual disability (NSID), while the boundary between true disease-causing mutations and non-disease-causing variants within this gene remains elusive. To investigate the relationship between ARX mutations and NSID, a panel comprising six reported causal mutations of the ARX was detected in 369 sporadic NSID patients and 550 random participants in Chinese. Two mutations, c.428_451 dup and p.G286S, may be disease-causing mutations for NSID, while p.Q163R and p.P353L showed a great predictive value in female NSID diagnosis with significant associations (X2 = 19.60, p = 9.54e-6 for p.Q163R; X2 = 25.70, p = 4.00e-07 for p.P353L), carriers of these mutations had an increased risk of NSID of more than fourfold. Detection of this panel also predicted significant associations between genetic variants of the ARX gene and NSID (p = 3.73e-4). The present study emphasized the higher genetic burden of the ARX gene on NSID in the Chinese population, molecular analysis of this gene should be considered for patients presenting NSID of unknown etiology.
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Affiliation(s)
- Yufei Wu
- Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Institute of Population and Health, Northwest University, Xi'an, 710069, China
| | - Huan Zhang
- The 2nd Affiliated Hospital, Xi'an Jiaotong University, Xi'an, 710004, China
| | - Xiaofen Liu
- Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Institute of Population and Health, Northwest University, Xi'an, 710069, China
| | - Zhangyan Shi
- Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Institute of Population and Health, Northwest University, Xi'an, 710069, China
| | - Hongling Li
- Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Institute of Population and Health, Northwest University, Xi'an, 710069, China
| | - Zhibin Wang
- Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Institute of Population and Health, Northwest University, Xi'an, 710069, China
| | - Xiaoyong Jie
- Xi'an Cangning Psychiatric Hospital, Xi'an, 710114, China
| | - Shaoping Huang
- The 2nd Affiliated Hospital, Xi'an Jiaotong University, Xi'an, 710004, China
| | - Fuchang Zhang
- Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Institute of Population and Health, Northwest University, Xi'an, 710069, China.,College of Public Management, Institute of Application Psychology, Northwest University, Xi'an, 710127, China
| | - Junlin Li
- Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Institute of Population and Health, Northwest University, Xi'an, 710069, China
| | - Kejin Zhang
- Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Institute of Population and Health, Northwest University, Xi'an, 710069, China.
| | - Xiaocai Gao
- Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Institute of Population and Health, Northwest University, Xi'an, 710069, China. .,College of Public Management, Institute of Application Psychology, Northwest University, Xi'an, 710127, China.
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Lumaka A, Race V, Peeters H, Corveleyn A, Coban-Akdemir Z, Jhangiani SN, Song X, Mubungu G, Posey J, Lupski JR, Vermeesch JR, Lukusa P, Devriendt K. A comprehensive clinical and genetic study in 127 patients with ID in Kinshasa, DR Congo. Am J Med Genet A 2018; 176:1897-1909. [PMID: 30088852 DOI: 10.1002/ajmg.a.40382] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Accepted: 06/06/2018] [Indexed: 12/21/2022]
Abstract
Pathogenic variants account for 4 to 41% of patients with intellectual disability (ID) or developmental delay (DD). In Sub-Saharan Africa, the prevalence of ID is thought to be higher, but data in Central Africa are limited to some case reports. In addition, clinical descriptions of some syndromes are not available for this population. This study aimed at providing an estimate for the fraction of ID/DD for which an underlying etiological genetic cause may be elucidated and provide insights into their clinical presentation in special institutions in a Central African country. A total of 127 patients (33 females and 94 males, mean age 10.03 ± 4.68 years), were recruited from six institutions across Kinshasa. A clinical diagnosis was achieved in 44 but molecular confirmation was achieved in 21 of the 22 patients with expected genetic defect (95% clinical sensitivity). Identified diseases included Down syndrome (15%), submicroscopic copy number variants (9%), aminoacylase deficiency (0.8%), Partington syndrome in one patient (0.8%) and his similarly affected brother, X-linked syndromic Mental Retardation type 33 (0.8%), and two conditions without clear underlying molecular genetic etiologies (Oculo-Auriculo-Vertebral and Amniotic Bands Sequence). We have shown that genetic etiologies, similar to those reported in Caucasian subjects, are a common etiologic cause of ID in African patients from Africa. We have confirmed the diagnostic utility of clinical characterization prior to genetic testing. Finally, our clinical descriptions provide insights into the presentation of these genetic diseases in African patients.
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Affiliation(s)
- Aimé Lumaka
- Centre for Human Genetics, Faculty of Medicine, University of Kinshasa, Kinshasa, DR, Congo.,Département des Sciences Biomédicales et Précliniques, GIGA-R, Laboratoire de Génétique Humaine, University of Liège, Liège, Belgium.,Institut National de Recherche Biomédicale, Kinshasa, DR, Congo.,Department of Pediatrics, Faculty of Medicine, University of Kinshasa, Kinshasa, DR, Congo
| | - Valerie Race
- Centre for Human Genetics, University Hospital, University of Leuven, Leuven, Belgium
| | - Hilde Peeters
- Centre for Human Genetics, University Hospital, University of Leuven, Leuven, Belgium
| | - Anniek Corveleyn
- Centre for Human Genetics, University Hospital, University of Leuven, Leuven, Belgium
| | - Zeynep Coban-Akdemir
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Shalini N Jhangiani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Xiaofei Song
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Gerrye Mubungu
- Centre for Human Genetics, Faculty of Medicine, University of Kinshasa, Kinshasa, DR, Congo.,Institut National de Recherche Biomédicale, Kinshasa, DR, Congo.,Department of Pediatrics, Faculty of Medicine, University of Kinshasa, Kinshasa, DR, Congo.,Centre for Human Genetics, University Hospital, University of Leuven, Leuven, Belgium
| | - Jennifer Posey
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas.,Department of Pediatrics, Baylor College of Medicine, Houston, Texas.,Genetics Clinic service, Texas Children's Hospital, Houston, Texas
| | - Joris R Vermeesch
- Centre for Human Genetics, University Hospital, University of Leuven, Leuven, Belgium
| | - Prosper Lukusa
- Centre for Human Genetics, Faculty of Medicine, University of Kinshasa, Kinshasa, DR, Congo.,Département des Sciences Biomédicales et Précliniques, GIGA-R, Laboratoire de Génétique Humaine, University of Liège, Liège, Belgium.,Institut National de Recherche Biomédicale, Kinshasa, DR, Congo.,Centre for Human Genetics, University Hospital, University of Leuven, Leuven, Belgium
| | - Koenraad Devriendt
- Centre for Human Genetics, University Hospital, University of Leuven, Leuven, Belgium
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Basal ganglia involvement in ARX patients: The reason for ARX patients very specific grasping? NEUROIMAGE-CLINICAL 2018; 19:454-465. [PMID: 29984154 PMCID: PMC6029499 DOI: 10.1016/j.nicl.2018.04.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 03/05/2018] [Accepted: 04/01/2018] [Indexed: 01/15/2023]
Abstract
The ARX (Aristaless Related homeoboX) gene was identified in 2002 as responsible for XLAG syndrome, a lissencephaly characterized by an almost complete absence of cortical GABAergic interneurons, and for milder forms of X-linked Intellectual Disability (ID) without apparent brain abnormalities. The most frequent mutation found in the ARX gene, a duplication of 24 base pairs (c.429_452dup24) in exon 2, results in a recognizable syndrome in which patients present ID without primary motor impairment, but with a very specific upper limb distal motor apraxia associated with a pathognomonic hand-grip, described as developmental Limb Kinetic Apraxia (LKA). In this study, we first present ARX expression during human fetal brain development showing that it is strongly expressed in GABAergic neuronal progenitors during the second and third trimester of pregnancy. We show that although ARX expression strongly decreases towards the end of gestation, it is still present after birth in some neurons of the basal ganglia, thalamus and cerebral cortex, suggesting that ARX also plays a role in more mature neuron functioning. Then, using morphometric brain MRI in 13 ARX patients carrying c.429_452dup24 mutation and in 13 sex- and age-matched healthy controls, we show that ARX patients have a significantly decreased volume of several brain structures including the striatum (and more specifically the caudate nucleus), hippocampus and thalamus as well as decreased precentral gyrus cortical thickness. We observe a significant correlation between caudate nucleus volume reduction and motor impairment severity quantified by kinematic parameter of precision grip. As basal ganglia are known to regulate sensorimotor processing and are involved in the control of precision gripping, the combined decrease in cortical thickness of primary motor cortex and basal ganglia volume in ARX dup24 patients is very likely the anatomical substrate of this developmental form of LKA. c.429_452dup24 in ARX is responsible for ID with Limb Kinetic Apraxia. During human brain development, ARX is expressed in GABAergic neuronal progenitors. ARX patients have a significantly decreased caudate nucleus volume by MRI. This caudate nucleus volume reduction is correlated with motor impairment severity. These anatomic findings may explain this developmental form of Limb Kinetic Apraxia.
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Key Words
- ARX
- ARX, Aristaless-Related homeoboX gene (according to the genetic convention, ARX was written in italics when it refers to the gene, in plain-text characters when it refers to the protein, in capital letters when it refers to the human gene, and in lowercase when it refers to the mouse gene)
- CGE, caudal ganglionic eminence
- CP, cortical plate
- DS, down syndrome
- GE, ganglionic eminences
- Human brain development
- ICV, intracranial volume
- ID, Intellectual Disability
- IQ, intelligence quotient
- IZ, intermediate zone
- Intellectual disability
- Kinematic
- LGE, lateral ganglionic eminence
- LKA, Limb Kinetic Apraxia
- Limb Kinetic Apraxia
- MGE, medial ganglionic eminence
- MRI, magnetic resonance imaging
- MZ, marginal zone
- Morphometric MRI
- ROI, region of interest
- SGL, subpial granular layer
- SVZ, subventricular zone
- VZ, ventricular zone
- WG, weeks of gestation
- XLAG, X-linked lissencephaly with abnormal genitalia
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Jackson MR, Lee K, Mattiske T, Jaehne EJ, Ozturk E, Baune BT, O'Brien TJ, Jones N, Shoubridge C. Extensive phenotyping of two ARX polyalanine expansion mutation mouse models that span clinical spectrum of intellectual disability and epilepsy. Neurobiol Dis 2017; 105:245-256. [DOI: 10.1016/j.nbd.2017.05.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 04/30/2017] [Accepted: 05/29/2017] [Indexed: 11/17/2022] Open
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8
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Kulkarni G, Ranade S. Molecular Analysis of Hotspot Regions ofARXandMECP2Genes in Intellectual Disability and Cornelia De Lange Syndrome. INT J HUM GENET 2017. [DOI: 10.1080/09723757.2017.1351119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Gayatri Kulkarni
- Department of Chemistry, Division of Biochemistry, Savitribai Phule Pune University, Pune 411 007, Maharashtra, India
| | - Suvidya Ranade
- Department of Chemistry, Division of Biochemistry, Savitribai Phule Pune University, Pune 411 007, Maharashtra, India
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9
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Marques I, Sá MJ, Soares G, Mota MDC, Pinheiro C, Aguiar L, Amado M, Soares C, Calado A, Dias P, Sousa AB, Fortuna AM, Santos R, Howell KB, Ryan MM, Leventer RJ, Sachdev R, Catford R, Friend K, Mattiske TR, Shoubridge C, Jorge P. Unraveling the pathogenesis of ARX polyalanine tract variants using a clinical and molecular interfacing approach. Mol Genet Genomic Med 2015; 3:203-14. [PMID: 26029707 PMCID: PMC4444162 DOI: 10.1002/mgg3.133] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 01/13/2015] [Accepted: 01/15/2015] [Indexed: 12/22/2022] Open
Abstract
The Aristaless-related homeobox (ARX) gene is implicated in intellectual disability with the most frequent pathogenic mutations leading to expansions of the first two polyalanine tracts. Here, we describe analysis of the ARX gene outlining the approaches in the Australian and Portuguese setting, using an integrated clinical and molecular strategy. We report variants in the ARX gene detected in 19 patients belonging to 17 families. Seven pathogenic variants, being expansion mutations in both polyalanine tract 1 and tract 2, were identifyed, including a novel mutation in polyalanine tract 1 that expands the first tract to 20 alanines. This precise number of alanines is sufficient to cause pathogenicity when expanded in polyalanine tract 2. Five cases presented a probably non-pathogenic variant, including the novel HGVS: c.441_455del, classified as unlikely disease causing, consistent with reports that suggest that in frame deletions in polyalanine stretches of ARX rarely cause intellectual disability. In addition, we identified five cases with a variant of unclear pathogenic significance. Owing to the inconsistent ARX variants description, publications were reviewed and ARX variant classifications were standardized and detailed unambiguously according to recommendations of the Human Genome Variation Society. In the absence of a pathognomonic clinical feature, we propose that molecular analysis of the ARX gene should be included in routine diagnostic practice in individuals with either nonsyndromic or syndromic intellectual disability. A definitive diagnosis of ARX-related disorders is crucial for an adequate clinical follow-up and accurate genetic counseling of at-risk family members.
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Affiliation(s)
- Isabel Marques
- Unidade de Genética Molecular, Centro de Genética Médica Doutor Jacinto Magalhães, Centro Hospitalar do Porto, EPE Porto, Portugal ; Unit for Multidisciplinary Research in Biomedicine, UMIB, ICBAS-UP Porto, Portugal
| | - Maria João Sá
- Unidade de Genética Médica, Centro de Genética Médica Doutor Jacinto Magalhães, Centro Hospitalar do Porto, EPE Porto, Portugal ; Unit for Multidisciplinary Research in Biomedicine, UMIB, ICBAS-UP Porto, Portugal
| | - Gabriela Soares
- Unidade de Genética Médica, Centro de Genética Médica Doutor Jacinto Magalhães, Centro Hospitalar do Porto, EPE Porto, Portugal
| | - Maria do Céu Mota
- Department of Pediatrics, Centro Hospitalar do Porto, EPE Porto, Portugal
| | - Carla Pinheiro
- Department of Pediatrics, Hospital Santa Maria Maior, EPE Barcelos, Portugal
| | - Lisa Aguiar
- Department of Pediatrics, Hospital Distrital de Santarém, EPE Santarém, Portugal
| | - Marta Amado
- Department of Pediatrics, Unidade Hospitalar de Portimão, Centro Hospitalar do Algarve Portimão, Portugal
| | - Christina Soares
- Department of Pediatrics, Unidade Hospitalar de Portimão, Centro Hospitalar do Algarve Portimão, Portugal
| | - Angelina Calado
- Department of Pediatrics, Unidade Hospitalar de Portimão, Centro Hospitalar do Algarve Portimão, Portugal
| | - Patrícia Dias
- Department of Genetics, Hospital de Santa Maria Lisboa, Portugal
| | - Ana Berta Sousa
- Department of Genetics, Hospital de Santa Maria Lisboa, Portugal
| | - Ana Maria Fortuna
- Unidade de Genética Médica, Centro de Genética Médica Doutor Jacinto Magalhães, Centro Hospitalar do Porto, EPE Porto, Portugal ; Unit for Multidisciplinary Research in Biomedicine, UMIB, ICBAS-UP Porto, Portugal
| | - Rosário Santos
- Unidade de Genética Molecular, Centro de Genética Médica Doutor Jacinto Magalhães, Centro Hospitalar do Porto, EPE Porto, Portugal ; Unit for Multidisciplinary Research in Biomedicine, UMIB, ICBAS-UP Porto, Portugal
| | - Katherine B Howell
- Department of Neurology, Royal Children's Hospital Melbourne, Victoria, Australia ; Murdoch Childrens Research Institute Melbourne, Victoria, Australia, 3052 ; University of Melbourne Department of Paediatrics Melbourne, Victoria, Australia, 3052
| | - Monique M Ryan
- Department of Neurology, Royal Children's Hospital Melbourne, Victoria, Australia ; Murdoch Childrens Research Institute Melbourne, Victoria, Australia, 3052 ; University of Melbourne Department of Paediatrics Melbourne, Victoria, Australia, 3052
| | - Richard J Leventer
- Department of Neurology, Royal Children's Hospital Melbourne, Victoria, Australia ; Murdoch Childrens Research Institute Melbourne, Victoria, Australia, 3052 ; University of Melbourne Department of Paediatrics Melbourne, Victoria, Australia, 3052
| | - Rani Sachdev
- Department of Medical Genetics, Sydney Children's Hospital High St., Randwick, New South Wales, 2031, Australia
| | - Rachael Catford
- SA Pathology at the Women's and Children's Hospital North Adelaide, South Australia, Australia
| | - Kathryn Friend
- SA Pathology at the Women's and Children's Hospital North Adelaide, South Australia, Australia
| | - Tessa R Mattiske
- Department of Paediatrics, University of Adelaide Adelaide, South Australia, 5006, Australia ; Robinson Research Institute, University of Adelaide Adelaide, South Australia, 5006, Australia
| | - Cheryl Shoubridge
- Department of Paediatrics, University of Adelaide Adelaide, South Australia, 5006, Australia ; Robinson Research Institute, University of Adelaide Adelaide, South Australia, 5006, Australia
| | - Paula Jorge
- Unidade de Genética Molecular, Centro de Genética Médica Doutor Jacinto Magalhães, Centro Hospitalar do Porto, EPE Porto, Portugal ; Unit for Multidisciplinary Research in Biomedicine, UMIB, ICBAS-UP Porto, Portugal
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10
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Curie A, Nazir T, Brun A, Paulignan Y, Reboul A, Delange K, Cheylus A, Bertrand S, Rochefort F, Bussy G, Marignier S, Lacombe D, Chiron C, Cossée M, Leheup B, Philippe C, Laugel V, De Saint Martin A, Sacco S, Poirier K, Bienvenu T, Souville I, Gilbert-Dussardier B, Bieth E, Kauffmann D, Briot P, de Fréminville B, Prieur F, Till M, Rooryck-Thambo C, Mortemousque I, Bobillier-Chaumont I, Toutain A, Touraine R, Sanlaville D, Chelly J, Freeman S, Kong J, Hadjikhani N, Gollub RL, Roy A, des Portes V. The c.429_452 duplication of the ARX gene: a unique developmental-model of limb kinetic apraxia. Orphanet J Rare Dis 2014; 9:25. [PMID: 24528893 PMCID: PMC4016261 DOI: 10.1186/1750-1172-9-25] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 01/22/2014] [Indexed: 12/16/2022] Open
Abstract
Background The c.429_452dup24 of the ARX gene is a rare genetic anomaly, leading to X-Linked Intellectual Disability without brain malformation. While in certain cases c.429_452dup24 has been associated with specific clinical patterns such as Partington syndrome, the consequence of this mutation has been also often classified as “non-specific Intellectual Disability”. The present work aims at a more precise description of the clinical features linked to the c.429_452dup24 mutation. Methods We clinically reviewed all affected patients identified in France over a five-year period, i.e. 27 patients from 12 different families. Detailed cognitive, behavioural, and motor evaluation, as well as standardized videotaped assessments of oro-lingual and gestural praxis, were performed. In a sub-group of 13 ARX patients, kinematic and MRI studies were further accomplished to better characterize the motor impairment prevalent in the ARX patients group. To ensure that data were specific to the ARX gene mutation and did not result from low-cognitive functioning per se, a group of 27 age- and IQ-matched Down syndrome patients served as control. Results Neuropsychological and motor assessment indicated that the c.429_452dup24 mutation constitutes a recognizable clinical syndrome: ARX patients exhibiting Intellectual Disability, without primary motor impairment, but with a very specific upper limb distal motor apraxia associated with a pathognomonic hand-grip. Patients affected with the so-called Partington syndrome, which involves major hand dystonia and orolingual apraxia, exhibit the most severe symptoms of the disorder. The particular “reach and grip” impairment which was observed in all ARX patients, but not in Down syndrome patients, was further characterized by the kinematic data: (i) loss of preference for the index finger when gripping an object, (ii) major impairment of fourth finger deftness, and (iii) a lack of pronation movements. This lack of distal movement coordination exhibited by ARX patients is associated with the loss of independent digital dexterity and is similar to the distortion of individual finger movements and posture observed in Limb Kinetic Apraxia. Conclusion These findings suggest that the ARX c.429_452dup24 mutation may be a developmental model for Limb Kinetic Apraxia.
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Affiliation(s)
- Aurore Curie
- Centre de Référence « Déficiences Intellectuelles de Causes Rares », Hôpital Femme Mère Enfant, Hospices Civils de Lyon, F-69677 Bron, France.
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11
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Deng H, Zheng W, Song Z. Genetics, Molecular Biology, and Phenotypes of X-Linked Epilepsy. Mol Neurobiol 2013; 49:1166-80. [DOI: 10.1007/s12035-013-8589-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Accepted: 11/05/2013] [Indexed: 11/25/2022]
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12
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Tiwari VN, Sundaram SK, Chugani HT, Huq AHMM. Infantile spasms are associated with abnormal copy number variations. J Child Neurol 2013; 28:1191-6. [PMID: 22914377 DOI: 10.1177/0883073812453496] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The authors tested the hypothesis that de novo copy number variations (CNVs) implicated in known genomic disorders ("pathogenic CNVs") are significant predisposing factors of infantile spasms. The authors performed a genome-wide analysis of single-nucleotide polymorphism genotyping microarray data to identify the role of de novo/known pathogenic large CNVs in 13 trios of children affected by infantile spasms. A rare, large (4.8 Mb) de novo duplication was detected in the 15q11-13 region of 1 patient. In addition, 3 known pathogenic CNVs (present in the patient as well as 1 of the parents) were detected in total. In 1 patient, a known pathogenic deletion was detected in the region of 2q32.3. Similarly, in 1 other patient, 2 known pathogenic deletions in the regions of 16p11.2 and Xp22.13 (containing CDKL5) were detected. These findings suggest that some specific pathogenic CNVs predispose to infantile spasms and may be associated with different phenotypes.
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Affiliation(s)
- Vijay N Tiwari
- 1Department of Pediatrics, Children's Hospital of Michigan, Wayne State University, Detroit, MI, USA
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13
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Tamura T, Sone M, Nakamura Y, Shimamura T, Imoto S, Miyano S, Okazawa H. A restricted level of PQBP1 is needed for the best longevity of Drosophila. Neurobiol Aging 2012; 34:356.e11-20. [PMID: 22901698 DOI: 10.1016/j.neurobiolaging.2012.07.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 07/21/2012] [Indexed: 12/13/2022]
Abstract
A number of neurological diseases are caused by mutations of RNA metabolism-related genes. A complicating issue is that whether under- or overfunction of such genes is responsible for the phenotype. Polyglutamine tract binding protein-1, a causative gene for X-linked mental retardation, is also involved in RNA metabolism, and both mutation and duplication of the gene were reported in human patients. In this study, we first report a novel phenotype of dPQBP1 (drosophila homolog of Polyglutamine tract binding protein-1)-mutant flies, lifespan shortening. We next address the gene dose-phenotype relationship in lifespan shortening and in learning disability, a previously described phenotype. The 2 phenotypes are rescued by dPQBP1 but in different dose-phenotype relationships. Either insufficient or excessive expression of dPQBP1 does not recover lifespan, while excessive expression recovers learning ability. We finally address the mechanism of lifespan shortening. Tissue-specific expression of dPQBP1-RNA interference construct reveals both neural and nonneural dPQBP1 contribute to the lifespan, while the latter has a dominant effect. Gene expression profiling suggested retinophilin/MORN repeat containing 4, a gene promoting axonal degeneration, to contribute to lifespan shortening by neural dPQBP1. Systems biology analysis of the gene expression profiles revealed indirect influence of dPQBP1 on insulin-like growth factor 1, insulin receptor, and peroxisome proliferator-activated receptorα/γ signaling pathways in nonneural tissues. Collectively, given that dPQBP1 affects multiple pathways in different dose-dependent and tissue-specific manners, dPQBP1 at a restricted expression level is needed for the best longevity.
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Affiliation(s)
- Takuya Tamura
- Department of Neuropathology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
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14
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Is there a Mendelian transmission ratio distortion of the c.429_452dup(24bp) polyalanine tract ARX mutation? Eur J Hum Genet 2012; 20:1311-4. [PMID: 22490986 DOI: 10.1038/ejhg.2012.61] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Intellectual disability is common. Aristaless-related homeobox (ARX) gene is one of the most frequently mutated and pleiotropic genes, implicated in 10 different phenotypes. More than half of ~100 reported cases with ARX mutations are due to a recurrent duplication of 24 bp, c.429_452dup, which leads to polyalanine tract expansion. The excess of affected males among the offspring of the obligate carrier females raised the possibility of transmission ratio distortion for the c.429_452dup mutation. We found a significant deviation from the expected Mendelian 1:1 ratio of transmission in favour of the c.429_452dup ARX mutation. We hypothesise that the preferential transmission of the c.429_452dup mutation may be due to asymmetry of meiosis in the oocyte. Our findings may have implications for genetic counselling of families segregating the c.429_452dup mutation and allude to putative role of ARX in oocyte biology.
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15
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PICCIONE MARIA, SANFILIPPO CINZIA, CAVANI SIMONA, SALATIELLO PATRIZIA, MALACARNE MICHELA, PIERLUIGI MAURO, FICHERA MARCO, LUCIANO DANIELA, CORSELLO GIOVANNI. Molecular and clinical characterization of a small duplication Xp in a human female with psychiatric disorders. J Genet 2011; 90:473-7. [DOI: 10.1007/s12041-011-0096-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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16
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Fullston T, Finnis M, Hackett A, Hodgson B, Brueton L, Baynam G, Norman A, Reish O, Shoubridge C, Gecz J. Screening and cell-based assessment of mutations in the Aristaless-related homeobox (ARX) gene. Clin Genet 2011; 80:510-22. [PMID: 21496008 DOI: 10.1111/j.1399-0004.2011.01685.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
ARX mutations cause a diverse spectrum of human disorders, ranging from severe brain and genital malformations to non-syndromic intellectual disability (ID). ARX is a transcription factor with multiple domains that include four polyalanine (pA) tracts, the first two of which are frequently expanded by mutations. We progressively screened DNA samples from 613 individuals with ID initially for the most frequent ARX mutations (c.304ins(GCG)(7)'expansion' of pA1 and c.429_452dup 'dup24bp' of pA2). Five hundred samples without pA1 or pA2 mutations had the entire ARX ORF screened by single stranded polymorphism conformation (SSCP) and/or denaturing high pressure liquid chromatography (dHPLC) analysis. Overall, eight families with six mutations in ARX were identified (1.31%): five duplication mutations in pA2 (0.82%) with three new clinical reports of families with the dup24bp and two duplications larger than the dup24bp mutation discovered (dup27bp, dup33bp); and three point mutations (0.6%), including one novel mutation in the homeodomain (c.1074G>T). Four ultraconserved regions distal to ARX (uc466-469) were also screened in a subset of 94 patients, with three unique nucleotide changes identified in two (uc466, uc467). The subcellular localization of full length ARX proteins was assessed for 11 variants. Protein mislocalization increased as a function of pA2 tract length and phenotypic severity, as has been previously suggested for pA1. Similarly, protein mislocalization of the homeodomain mutations also correlated with clinical severity, suggesting an emerging genotype vs cellular phenotype correlation.
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Affiliation(s)
- T Fullston
- Neurogenetics Laboratory, Genetics and Molecular Pathology, SA Pathology at the Women's and Children's Hospital, Adelaide, South Australia, Australia
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Ekşioğlu YZ, Pong AW, Takeoka M. A novel mutation in the aristaless domain of the ARX gene leads to Ohtahara syndrome, global developmental delay, and ambiguous genitalia in males and neuropsychiatric disorders in females. Epilepsia 2011; 52:984-92. [DOI: 10.1111/j.1528-1167.2011.02980.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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18
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Cossée M, Faivre L, Philippe C, Hichri H, de Saint-Martin A, Laugel V, Bahi-Buisson N, Lemaitre JF, Leheup B, Delobel B, Demeer B, Poirier K, Biancalana V, Pinoit JM, Julia S, Chelly J, Devys D, Mandel JL. ARX polyalanine expansions are highly implicated in familial cases of mental retardation with infantile epilepsy and/or hand dystonia. Am J Med Genet A 2010; 155A:98-105. [DOI: 10.1002/ajmg.a.33785] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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19
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Drosophila PQBP1 regulates learning acquisition at projection neurons in aversive olfactory conditioning. J Neurosci 2010; 30:14091-101. [PMID: 20962230 DOI: 10.1523/jneurosci.1319-10.2010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Polyglutamine tract-binding protein-1 (PQBP1) is involved in the transcription-splicing coupling, and its mutations cause a group of human mental retardation syndromes. We generated a fly model in which the Drosophila homolog of PQBP1 (dPQBP1) is repressed by insertion of piggyBac. In classical odor conditioning, learning acquisition was significantly impaired in homozygous piggyBac-inserted flies, whereas the following memory retention was completely normal. Mushroom bodies (MBs) and antennal lobes were morphologically normal in dPQBP1-mutant flies. Projection neurons (PNs) were not reduced in number and their fiber connections were not changed, whereas gene expressions including NMDA receptor subunit 1 (NR1) were decreased in PNs. Targeted double-stranded RNA-mediated silencing of dPQBP1 in PNs, but not in MBs, similarly disrupted learning acquisition. NR1 overexpression in PNs rescued the learning disturbance of dPQBP1 mutants. HDAC (histone deacetylase) inhibitors, SAHA (suberoylanilide hydroxamic acid) and PBA (phenylbutyrate), that upregulated NR1 partially rescued the learning disturbance. Collectively, these findings identify dPQBP1 as a novel gene regulating learning acquisition at PNs.
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20
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Shoubridge C, Fullston T, Gécz J. ARX spectrum disorders: making inroads into the molecular pathology. Hum Mutat 2010; 31:889-900. [PMID: 20506206 DOI: 10.1002/humu.21288] [Citation(s) in RCA: 130] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Aristaless-related homeobox gene (ARX) is one of the most frequently mutated genes in a spectrum of X-chromosome phenotypes with intellectual disability (ID) as their cardinal feature. To date, close to 100 families and isolated cases have been reported to carry 44 different mutations, the majority of these (59%) being a result of polyalanine tract expansions. At least 10 well-defined clinical entities, including Ohtahara, Partington, and Proud syndromes, X-linked infantile spasms, X-linked lissencephaly with ambiguous genitalia, X-linked myoclonic epilepsy and nonsyndromic intellectual disability have been ascertained from among the patients with ARX mutations. The striking intra- and interfamilial pleiotropy together with genetic heterogeneity (same clinical entities associated with different ARX mutations) are becoming a hallmark of ARX mutations. Although males are predominantly affected, some mutations associated with malformation phenotypes in males also show a phenotype in carrier females. Recent progress in the study of the effect of ARX mutations through sophisticated animal (mice) and cellular models begins to provide crucial insights into the molecular function of ARX and associated molecular pathology, thus guiding future inquiries into therapeutic interventions.
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Affiliation(s)
- Cheryl Shoubridge
- Department of Genetics and Molecular Pathology, SA Pathology at the Women's and Children's Hospital, North Adelaide, South Australia 5006, Australia.
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21
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Nabbout R, Depienne C, Chipaux M, Girard B, Souville I, Trouillard O, Dulac O, Chelly J, Afenjar A, Héron D, Leguern E, Beldjord C, Bienvenu T, Bahi-Buisson N. CDKL5 and ARX mutations are not responsible for early onset severe myoclonic epilepsy in infancy. Epilepsy Res 2009; 87:25-30. [DOI: 10.1016/j.eplepsyres.2009.07.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Revised: 06/02/2009] [Accepted: 07/15/2009] [Indexed: 11/26/2022]
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22
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Reish O, Fullston T, Regev M, Heyman E, Gecz J. A novel de novo 27 bp duplication of the ARX gene, resulting from postzygotic mosaicism and leading to three severely affected males in two generations. Am J Med Genet A 2009; 149A:1655-60. [PMID: 19606478 DOI: 10.1002/ajmg.a.32842] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The Aristaless Related Homeobox (ARX) gene is a Q(50) paired homeobox gene. These genes are important regulators of essential events during vertebrate embryogenesis, including the development of the central and peripheral nervous system. Mutations in ARX have been identified in at least 82 different families and sporadic cases, and are responsible for at least 8 clinically distinct disorders. The recurrent 24 bp duplication (dup) mutation, c.429_452dup(24 bp), is the most frequent ARX mutation, which accounts for 45% of all cases reported to date. Here we report a novel de novo, familial dup mutation of 27 bp, c.430_456dup(27 bp), which involves the same region of the ARX gene in exon 2, as the dup24 bp mutation. The female progenitor of this dup27 bp allele exhibits mosaicism, likely resulting from a postmitotic de novo mutation event early in embryonic development. Three males with the dup27 bp mutation presented with infantile spasms, two of whom died early in life. Their phenotype appeared more severe, when compared to the spectrum of clinical presentations associated with the dup24 bp mutation. We propose that this might be at least partly due to the single, extra alanine residue (A) (21A in dup27 vs. 20A in dup24), which takes polyalanine tract 2 of ARX beyond the maximum, naturally occurring limit of 20A found in the human genome.
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Affiliation(s)
- Orit Reish
- Genetic Institute, Assaf Harofeh Medical Center, Zerifin, Israel
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23
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Humeau Y, Gambino F, Chelly J, Vitale N. X-linked mental retardation: focus on synaptic function and plasticity. J Neurochem 2009; 109:1-14. [DOI: 10.1111/j.1471-4159.2009.05881.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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24
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Fulp CT, Cho G, Marsh ED, Nasrallah IM, Labosky PA, Golden JA. Identification of Arx transcriptional targets in the developing basal forebrain. Hum Mol Genet 2008; 17:3740-60. [PMID: 18799476 PMCID: PMC2581427 DOI: 10.1093/hmg/ddn271] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Mutations in the aristaless-related homeobox (ARX) gene are associated with multiple neurologic disorders in humans. Studies in mice indicate Arx plays a role in neuronal progenitor proliferation and development of the cerebral cortex, thalamus, hippocampus, striatum, and olfactory bulbs. Specific defects associated with Arx loss of function include abnormal interneuron migration and subtype differentiation. How disruptions in ARX result in human disease and how loss of Arx in mice results in these phenotypes remains poorly understood. To gain insight into the biological functions of Arx, we performed a genome-wide expression screen to identify transcriptional changes within the subpallium in the absence of Arx. We have identified 84 genes whose expression was dysregulated in the absence of Arx. This population was enriched in genes involved in cell migration, axonal guidance, neurogenesis, and regulation of transcription and includes genes implicated in autism, epilepsy, and mental retardation; all features recognized in patients with ARX mutations. Additionally, we found Arx directly repressed three of the identified transcription factors: Lmo1, Ebf3 and Shox2. To further understand how the identified genes are involved in neural development, we used gene set enrichment algorithms to compare the Arx gene regulatory network (GRN) to the Dlx1/2 GRN and interneuron transcriptome. These analyses identified a subset of genes in the Arx GRN that are shared with that of the Dlx1/2 GRN and that are enriched in the interneuron transcriptome. These data indicate Arx plays multiple roles in forebrain development, both dependent and independent of Dlx1/2, and thus provides further insights into the understanding of the mechanisms underlying the pathology of mental retardation and epilepsy phenotypes resulting from ARX mutations.
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Affiliation(s)
- Carl T Fulp
- Neuroscience Graduate Group, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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Rujirabanjerd S, Tongsippunyoo K, Sripo T, Limprasert P. Mutation screening of the Aristaless-related homeobox (ARX) gene in Thai pediatric patients with delayed development: first report from Thailand. Eur J Med Genet 2007; 50:346-54. [PMID: 17613295 DOI: 10.1016/j.ejmg.2007.05.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2007] [Accepted: 05/17/2007] [Indexed: 10/23/2022]
Abstract
Mutations in the Aristaless-related homeobox gene, ARX, have been a cause of X-linked mental retardation (XLMR) and are responsible for a vast phenotypic spectrum including syndromic and non-syndromic forms of mental retardation. Since the gene was initially identified, it has been generally screened in several patients with XLMR. This study is the first report of ARX mutational screening in Thai pediatric patients with delayed development. Two hundred and fifty-one patients participated in this study. Two hundred and three of the 251 patients were initially referred for molecular diagnosis of the Fragile XA syndrome and had negative test results. The remaining 48 patients were specifically recruited for the ARX mutational analysis and had previously reported phenotypes of the ARX mutations. Screening for the c.428_451 dup mutation was performed in all samples. Screening for other point mutations in all coding exons was performed in all 48 patients recruited for the ARX mutational analysis and in 29 patients initially referred for diagnosis of the Fragile XA syndrome who had two or more affected males in the family suggesting an X-linked inheritance pattern. Two patients were found to have the c.428_451 dup mutation. Considering genotype-phenotype correlation, we suggest screening of the most common mutation, the c.428_451 dup mutation by PCR, in patients with infantile spasm syndrome, Partington syndrome and non-syndromic X-linked mental retardation. Screening in patients who have negative Fragile XA test results should be considered when no other known causes of mental retardation are identified especially in families with suggestive X-linked inheritance pattern.
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Affiliation(s)
- Sinitdhorn Rujirabanjerd
- Department of Pathology, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand.
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Laperuta C, Spizzichino L, D'Adamo P, Monfregola J, Maiorino A, D'Eustacchio A, Ventruto V, Neri G, D'Urso M, Chiurazzi P, Ursini MV, Miano MG. MRX87 family with Aristaless X dup24bp mutation and implication for polyAlanine expansions. BMC MEDICAL GENETICS 2007; 8:25. [PMID: 17480217 PMCID: PMC1868705 DOI: 10.1186/1471-2350-8-25] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2006] [Accepted: 05/04/2007] [Indexed: 12/02/2022]
Abstract
Background Cognitive impairments are heterogeneous conditions, and it is estimated that 10% may be caused by a defect of mental function genes on the X chromosome. One of those genes is Aristaless related homeobox (ARX) encoding a polyA-rich homeobox transcription factor essential for cerebral patterning and its mutations cause different neurologic disorders. We reported on the clinical and genetic analysis of an Italian family with X-linked mental retardation (XLMR) and intra-familial heterogeneity, and provided insight into its molecular defect. Methods We carried out on linkage-candidate gene studies in a new MRX family (MRX87). All coding regions and exon-intron boundaries of ARX gene were analysed by direct sequencing. Results MRX87 patients had moderate to profound cognition impairment and a combination of minor congenital anomalies. The disease locus, MRX87, was mapped between DXS7104 and DXS1214, placing it in Xp22-p21 interval, a hot spot region for mental handicap. An in frame duplication of 24 bp (ARXdup24) in the second polyAlanine tract (polyA_II) in ARX was identified. Conclusion Our study underlines the role of ARXdup24 as a critical mutational site causing mental retardation linked to Xp22. Phenotypic heterogeneity of MRX87 patients represents a new observation relevant to the functional consequences of polyAlanine expansions enriching the puzzling complexity of ARXdup24-linked diseases.
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Affiliation(s)
- Carmela Laperuta
- Institute of Genetics and Biophysics "Adriano Buzzati Traverso" CNR, Naples, Italy
| | | | - Pio D'Adamo
- Telethon Institute of Genetics and Medicine, TIGEM, Naples, Italy
| | - Jlenia Monfregola
- Institute of Genetics and Biophysics "Adriano Buzzati Traverso" CNR, Naples, Italy
| | | | | | - Valerio Ventruto
- Institute of Genetics and Biophysics "Adriano Buzzati Traverso" CNR, Naples, Italy
| | | | - Michele D'Urso
- Institute of Genetics and Biophysics "Adriano Buzzati Traverso" CNR, Naples, Italy
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Colombo E, Collombat P, Colasante G, Bianchi M, Long J, Mansouri A, Rubenstein JLR, Broccoli V. Inactivation of Arx, the murine ortholog of the X-linked lissencephaly with ambiguous genitalia gene, leads to severe disorganization of the ventral telencephalon with impaired neuronal migration and differentiation. J Neurosci 2007; 27:4786-98. [PMID: 17460091 PMCID: PMC4916654 DOI: 10.1523/jneurosci.0417-07.2007] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2006] [Revised: 03/05/2007] [Accepted: 03/06/2007] [Indexed: 11/21/2022] Open
Abstract
ARX loss-of-function mutations cause X-linked lissencephaly with ambiguous genitalia (XLAG), a severe neurological condition that results in profound brain malformations, including microcephaly, absence of corpus callosum, and impairment of the basal ganglia. Despite such dramatic defects, their nature and origin remain largely unknown. Here, we used Arx mutant mice as a model to characterize the cellular and molecular mechanisms underlying the basal ganglia alterations. In these animals, the early differentiation of this tissue appeared normal, whereas subsequent differentiation was impaired, leading to the periventricular accumulation of immature neurons in both the lateral ganglionic eminence and medial ganglionic eminence (MGE). Both tangential migration toward the cortex and striatum and radial migration to the globus pallidus and striatum were greatly reduced in the mutants, causing a periventricular accumulation of NPY+ or calretinin+ neurons in the MGE. Arx mutant neurons retained their differentiation potential in vitro but exhibited deficits in morphology and migration ability. These findings imply that cell-autonomous defects in migration underlie the neuronal localization defects. Furthermore, Arx mutants lacked a large fraction of cholinergic neurons and displayed a strong impairment of thalamocortical projections, in which major axon fiber tracts failed to traverse the basal ganglia. Altogether, these results highlight the critical functions of Arx in promoting neural migration and regulating basal ganglia differentiation in mice, consistent with the phenotype of XLAG patients.
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Affiliation(s)
- Elena Colombo
- Stem Cell Research Department, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Patrick Collombat
- Department of Molecular Cell Biology, Max-Planck Institute for Biophysical Chemistry, 37077 Goettingen, Germany, and
| | - Gaia Colasante
- Stem Cell Research Department, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Marta Bianchi
- Stem Cell Research Department, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Jason Long
- Nina Ireland Laboratory of Developmental Neurobiology, Department of Psychiatry, University of California, San Francisco, San Francisco, California 94158
| | - Ahmed Mansouri
- Department of Molecular Cell Biology, Max-Planck Institute for Biophysical Chemistry, 37077 Goettingen, Germany, and
| | - John L. R. Rubenstein
- Nina Ireland Laboratory of Developmental Neurobiology, Department of Psychiatry, University of California, San Francisco, San Francisco, California 94158
| | - Vania Broccoli
- Stem Cell Research Department, San Raffaele Scientific Institute, 20132 Milan, Italy
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Chaste P, Nygren G, Anckarsäter H, Råstam M, Coleman M, Leboyer M, Gillberg C, Betancur C. Mutation screening of the ARX gene in patients with autism. Am J Med Genet B Neuropsychiatr Genet 2007; 144B:228-30. [PMID: 17044103 PMCID: PMC4826442 DOI: 10.1002/ajmg.b.30440] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Mutations in the Aristaless related homeobox (ARX) gene are associated with a broad spectrum of disorders, including nonsyndromic X-linked mental retardation, sometimes associated with epilepsy, as well as syndromic forms with brain abnormalities and abnormal genitalia. Furthermore, ARX mutations have been described in a few patients with autism or autistic features. In this study, we screened the ARX gene in 226 male patients with autism spectrum disorders and mental retardation; 42 of the patients had epilepsy. The mutation analysis was performed by direct sequencing of all exons and flanking regions. No ARX mutations were identified in any of the patients tested. These findings indicate that mutations in the ARX gene are very rare in autism.
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Affiliation(s)
- Pauline Chaste
- Neurobiologie et Psychiatrie
INSERM U513Université Paris XII9 quai Saint Bernard 75252 Paris Cedex 05, France
- Service de psychopathologie de l'enfant et de l'adolescent
Assistance Publique - Hôpitaux de Paris (AP-HP)Hôpital Robert DebréUniversité Paris Diderot - Paris 748 Boulvard Sérurier 75019 Paris, France
| | - Gudrun Nygren
- Department of Child and Adolescent Psychiatry
Gothenburg University405 30 Göteborg, Sweden
| | - Henrik Anckarsäter
- Department of Child and Adolescent Psychiatry
Gothenburg University405 30 Göteborg, Sweden
| | - Maria Råstam
- Department of Child and Adolescent Psychiatry
Gothenburg University405 30 Göteborg, Sweden
| | - Mary Coleman
- Department of Pediatrics
Georgetown University School of Medicine3900 Reservoir Rd NW, Washington, DC 20007, USA
| | - Marion Leboyer
- Neurobiologie et Psychiatrie
INSERM U513Université Paris XII9 quai Saint Bernard 75252 Paris Cedex 05, France
- Département de Psychiatrie
Assistance Publique - Hôpitaux de Paris (AP-HP)Hôpital Albert Chenevier40 Rue de Mesly 94000 Créteil, France
| | - Christopher Gillberg
- Department of Child and Adolescent Psychiatry
Gothenburg University405 30 Göteborg, Sweden
- Department of Child and Adolescent Psychiatry
Saint George's Hospital Medical SchoolCranmer Terrace, London SW17 0RE, UK
| | - Catalina Betancur
- Neurobiologie et Psychiatrie
INSERM U513Université Paris XII9 quai Saint Bernard 75252 Paris Cedex 05, France
- * Correspondence should be addressed to Catalina Betancur
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Tarpey PS, Raymond FL, O'Meara S, Edkins S, Teague J, Butler A, Dicks E, Stevens C, Tofts C, Avis T, Barthorpe S, Buck G, Cole J, Gray K, Halliday K, Harrison R, Hills K, Jenkinson A, Jones D, Menzies A, Mironenko T, Perry J, Raine K, Richardson D, Shepherd R, Small A, Varian J, West S, Widaa S, Mallya U, Moon J, Luo Y, Holder S, Smithson SF, Hurst JA, Clayton-Smith J, Kerr B, Boyle J, Shaw M, Vandeleur L, Rodriguez J, Slaugh R, Easton DF, Wooster R, Bobrow M, Srivastava AK, Stevenson RE, Schwartz CE, Turner G, Gecz J, Futreal PA, Stratton MR, Partington M. Mutations in CUL4B, which encodes a ubiquitin E3 ligase subunit, cause an X-linked mental retardation syndrome associated with aggressive outbursts, seizures, relative macrocephaly, central obesity, hypogonadism, pes cavus, and tremor. Am J Hum Genet 2007; 80:345-52. [PMID: 17236139 PMCID: PMC1785336 DOI: 10.1086/511134] [Citation(s) in RCA: 171] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2006] [Accepted: 11/20/2006] [Indexed: 12/23/2022] Open
Abstract
We have identified three truncating, two splice-site, and three missense variants at conserved amino acids in the CUL4B gene on Xq24 in 8 of 250 families with X-linked mental retardation (XLMR). During affected subjects' adolescence, a syndrome emerged with delayed puberty, hypogonadism, relative macrocephaly, moderate short stature, central obesity, unprovoked aggressive outbursts, fine intention tremor, pes cavus, and abnormalities of the toes. This syndrome was first described by Cazebas et al., in a family that was included in our study and that carried a CUL4B missense variant. CUL4B is a ubiquitin E3 ligase subunit implicated in the regulation of several biological processes, and CUL4B is the first XLMR gene that encodes an E3 ubiquitin ligase. The relatively high frequency of CUL4B mutations in this series indicates that it is one of the most commonly mutated genes underlying XLMR and suggests that its introduction into clinical diagnostics should be a high priority.
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Affiliation(s)
- Patrick S Tarpey
- Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
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Bottani A, Chelly J, de Brouwer APM, Pardo B, Barker M, Capra V, Bartoloni L, Antonarakis SE, Conrad B. Sequence variation in ultraconserved and highly conserved elements does not cause X-linked mental retardation. Am J Med Genet A 2007; 143A:888-90. [PMID: 17352392 DOI: 10.1002/ajmg.a.31651] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Armand Bottani
- Department of Genetic Medicine and Development, Geneva University Medical School and University Hospitals, Geneva, Switzerland
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de Souza Gestinari-Duarte R, Santos-Rebouças CB, Pimentel MMG. Mutational screening of ARX gene in Brazilian males with mental retardation of unknown etiology. J Hum Genet 2006; 51:737-740. [PMID: 16845484 DOI: 10.1007/s10038-006-0014-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Accepted: 05/08/2006] [Indexed: 11/30/2022]
Abstract
ARX gene mutations have been known as important causes of developmental and neurological disorders and are responsible for a large spectrum of abnormal phenotypes, includeing syndromic as well as nonsyndromic forms of mental retardation. We have screened the entire coding and flanking intronic sequences of ARX gene in 143 mentally impaired males in order to investigate the contribution of ARX mutations to mental retardation in the population of Rio de Janeiro, Brazil. Three sequence variants were identified: one patient had the most recurrent mutation already observed in ARX gene, the c.428_451dup(24 bp), two patients presented the c.1347C>T (p.G449G) in exon 4, and one patient had the intronic variant c.1074-3T>C. Although two of these alterations were considered polymorphisms, the known pathogenic variant c.428_451dup(24 bp) was found at a high rate (4.8%) among X-linked mental retardation (XLMR) families. Our results, the first in Latin America, reinforce the idea that ARX mutations are relevant to mental retardation and are indicative that molecular screening of exon 2 should be considered in males with mental retardation of unknown etiology, associated or not with neurological manifestations, especially in familial cases.
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Affiliation(s)
- Raquel de Souza Gestinari-Duarte
- Serviço de Genética Humana, Departamento de Biologia Celular e Genética, Instituto de Biologia Roberto Alcântara Gomes, Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier 524, PHLC sala 500, Maracanã, Rio de Janeiro, 20550-013, Brazil
| | - Cíntia Barros Santos-Rebouças
- Serviço de Genética Humana, Departamento de Biologia Celular e Genética, Instituto de Biologia Roberto Alcântara Gomes, Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier 524, PHLC sala 500, Maracanã, Rio de Janeiro, 20550-013, Brazil
| | - Márcia Mattos Gonçalves Pimentel
- Serviço de Genética Humana, Departamento de Biologia Celular e Genética, Instituto de Biologia Roberto Alcântara Gomes, Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier 524, PHLC sala 500, Maracanã, Rio de Janeiro, 20550-013, Brazil.
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Gécz J, Cloosterman D, Partington M. ARX: a gene for all seasons. Curr Opin Genet Dev 2006; 16:308-16. [PMID: 16650978 DOI: 10.1016/j.gde.2006.04.003] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Accepted: 04/18/2006] [Indexed: 02/02/2023]
Abstract
The Aristaless-related homeobox gene, ARX, is an important transcription factor with a crucial role in forebrain, pancreas and testes development. At least fifty-nine mutations have been described in the ARX gene in seven X-chromosome linked disorders involving mental retardation. Recent studies with ARX screening suggest that the gene is mutated in 9.5% of X-linked families with these disorders. Two different polyalanine expansion mutations represent 46% of all currently known mutations and show considerable pleiotropy. The ARX gene is emerging as one of the more important disease-causing genes on the X chromosome and ought to be considered for routine screening. Although the normal Arx protein is known to be a bifunctional transcriptional activator and repressor, the complete biochemical characterization of the normal and mutated ARX awaits further investigation. Pax4 was identified as one of the ARX target genes, and both proteins have crucial functions in endocrine mouse pancreas alpha-cell and beta-cell lineage specification.
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Affiliation(s)
- Jozef Gécz
- Department of Genetic Medicine, Women's and Children's Hospital, North Adelaide, South Australia 5006, Australia.
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