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Kehinde TA, Bhatia A, Olarewaju B, Shoaib MZ, Mousa J, Osundiji MA. Syndromic obesity with neurodevelopmental delay: Opportunities for targeted interventions. Eur J Med Genet 2022; 65:104443. [DOI: 10.1016/j.ejmg.2022.104443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 01/09/2022] [Accepted: 01/22/2022] [Indexed: 01/01/2023]
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2
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Hori T, Ikuta S, Hattori S, Takao K, Miyakawa T, Koike C. Mice with mutations in Trpm1, a gene in the locus of 15q13.3 microdeletion syndrome, display pronounced hyperactivity and decreased anxiety-like behavior. Mol Brain 2021; 14:61. [PMID: 33785025 PMCID: PMC8008678 DOI: 10.1186/s13041-021-00749-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 02/08/2021] [Indexed: 11/10/2022] Open
Abstract
The 15q13.3 microdeletion syndrome is a genetic disorder characterized by a wide spectrum of psychiatric disorders that is caused by the deletion of a region containing 7 genes on chromosome 15 (MTMR10, FAN1, TRPM1, MIR211, KLF13, OTUD7A, and CHRNA7). The contribution of each gene in this syndrome has been studied using mutant mouse models, but no single mouse model recapitulates the whole spectrum of human 15q13.3 microdeletion syndrome. The behavior of Trpm1-/- mice has not been investigated in relation to 15q13.3 microdeletion syndrome due to the visual impairment in these mice, which may confound the results of behavioral tests involving vision. We were able to perform a comprehensive behavioral test battery using Trpm1 null mutant mice to investigate the role of Trpm1, which is thought to be expressed solely in the retina, in the central nervous system and to examine the relationship between TRPM1 and 15q13.3 microdeletion syndrome. Our data demonstrate that Trpm1-/- mice exhibit abnormal behaviors that may explain some phenotypes of 15q13.3 microdeletion syndrome, including reduced anxiety-like behavior, abnormal social interaction, attenuated fear memory, and the most prominent phenotype of Trpm1 mutant mice, hyperactivity. While the ON visual transduction pathway is impaired in Trpm1-/- mice, we did not detect compensatory high sensitivities for other sensory modalities. The pathway for visual impairment is the same between Trpm1-/- mice and mGluR6-/- mice, but hyperlocomotor activity has not been reported in mGluR6-/- mice. These data suggest that the phenotype of Trpm1-/- mice extends beyond that expected from visual impairment alone. Here, we provide the first evidence associating TRPM1 with impairment of cognitive function similar to that observed in phenotypes of 15q13.3 microdeletion syndrome.
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Affiliation(s)
- Tesshu Hori
- Graduate School of Pharmacy, Ritsumeikan University, Kusatsu, Shiga, Japan
- Laboratory for Systems Neuroscience and Developmental Biology, College of Pharmaceutical Sciences, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Shohei Ikuta
- Laboratory for Systems Neuroscience and Developmental Biology, College of Pharmaceutical Sciences, Ritsumeikan University, Kusatsu, Shiga, Japan
- Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Satoko Hattori
- Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan
| | - Keizo Takao
- Department of Behavioral Physiology, Faculty of Medicine, University of Toyama, Toyama, Toyama, Japan
- Research Center for Idling Brain Science, University of Toyama, Toyama, Toyama, Japan
- Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, Okazaki, Aichi, Japan
| | - Tsuyoshi Miyakawa
- Department of Behavioral Physiology, Faculty of Medicine, University of Toyama, Toyama, Toyama, Japan
| | - Chieko Koike
- Graduate School of Pharmacy, Ritsumeikan University, Kusatsu, Shiga, Japan.
- Laboratory for Systems Neuroscience and Developmental Biology, College of Pharmaceutical Sciences, Ritsumeikan University, Kusatsu, Shiga, Japan.
- Center for Systems Vision Science, Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, Shiga, Japan.
- Ritsumeikan Global Innovation Research Organization (R-GIRO), Ritsumeikan University, Kusatsu, Shiga, Japan.
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3
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Liao J, Coffman KA, Locker J, Padiath QS, Nmezi B, Filipink RA, Hu J, Sathanoori M, Madan-Khetarpal S, McGuire M, Schreiber A, Moran R, Friedman N, Hoffner L, Rajkovic A, Yatsenko SA, Surti U. Deletion of conserved non-coding sequences downstream from NKX2-1: A novel disease-causing mechanism for benign hereditary chorea. Mol Genet Genomic Med 2021; 9:e1647. [PMID: 33666368 PMCID: PMC8123744 DOI: 10.1002/mgg3.1647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 02/18/2021] [Accepted: 02/19/2021] [Indexed: 11/17/2022] Open
Abstract
Background Benign hereditary chorea (BHC) is an autosomal dominant disorder characterized by early‐onset non‐progressive involuntary movements. Although NKX2‐1 mutations or deletions are the cause of BHC, some BHC families do not have pathogenic alterations in the NKX2‐1 gene, indicating that mutations of non‐coding regulatory elements of NKX2‐1 may also play a role. Methods and Results By using whole‐genome microarray analysis, we identified a 117 Kb founder deletion in three apparently unrelated BHC families that were negative for NKX2‐1 sequence variants. Targeted next generation sequencing analysis confirmed the deletion and showed that it was part of a complex local genomic rearrangement. In addition, we also detected a 648 Kb de novo deletion in an isolated BHC case. Both deletions are located downstream from NKX2‐1 on chromosome 14q13.2‐q13.3 and share a 33 Kb smallest region of overlap with six previously reported cases. This region has no gene but contains multiple evolutionarily highly conserved non‐coding sequences. Conclusion We propose that the deletion of potential regulatory elements necessary for NKX2‐1 expression in this critical region is responsible for BHC phenotype in these patients, and this is a novel disease‐causing mechanism for BHC.
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Affiliation(s)
- Jun Liao
- Pittsburgh Cytogenetics Laboratory, Magee-Womens Hospital of UPMC, Pittsburgh, PA, USA.,Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Keith A Coffman
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Joseph Locker
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Quasar S Padiath
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Bruce Nmezi
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Robyn A Filipink
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jie Hu
- Pittsburgh Cytogenetics Laboratory, Magee-Womens Hospital of UPMC, Pittsburgh, PA, USA.,Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Malini Sathanoori
- Pittsburgh Cytogenetics Laboratory, Magee-Womens Hospital of UPMC, Pittsburgh, PA, USA.,Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Marianne McGuire
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | | | - Rocio Moran
- Genomic Medicine Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Neil Friedman
- Center for Pediatric Neurology, Cleveland Clinic, Cleveland, OH, USA
| | - Lori Hoffner
- Magee Womens Research Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Aleksandar Rajkovic
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.,Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA, USA.,Magee Womens Research Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Svetlana A Yatsenko
- Pittsburgh Cytogenetics Laboratory, Magee-Womens Hospital of UPMC, Pittsburgh, PA, USA.,Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.,Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA, USA.,Magee Womens Research Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Urvashi Surti
- Pittsburgh Cytogenetics Laboratory, Magee-Womens Hospital of UPMC, Pittsburgh, PA, USA.,Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.,Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.,Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA, USA.,Magee Womens Research Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
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4
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Al-Absi AR, Qvist P, Glerup S, Sanchez C, Nyengaard JR. Df(h15q13)/+ Mouse Model Reveals Loss of Astrocytes and Synaptic-Related Changes of the Excitatory and Inhibitory Circuits in the Medial Prefrontal Cortex. Cereb Cortex 2021; 31:1609-1621. [PMID: 33123721 DOI: 10.1093/cercor/bhaa313] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 08/19/2020] [Accepted: 09/20/2020] [Indexed: 11/13/2022] Open
Abstract
The 15q13.3 deletion is associated with multiple neurodevelopmental disorders including epilepsy, schizophrenia, and autism. The Df(h15q13)/+ mouse model was recently generated that recapitulates several phenotypic features of the human 15q13.3 deletion syndrome (DS). However, the biological substrates underlying these phenotypes in Df(h15q13)/+ mice have not yet been fully characterized. RNA sequencing followed by real-time quantitative PCR, western blotting, liquid chromatography-mass spectrometry, and stereological analysis were employed to dissect the molecular, structural, and neurochemical phenotypes of the medial prefrontal cortex (mPFC) circuits in Df(h15q13)/+ mouse model. Transcriptomic profiling revealed enrichment for astrocyte-specific genes among differentially expressed genes, translated by a decrease in the number of glial fibrillary acidic protein positive cells in mPFC of Df(h15q13)/+ mice compared with wild-type mice. mPFC in Df(h15q13)/+ mice also showed a deficit of the inhibitory presynaptic marker GAD65, in addition to a reduction in dendritic arborization and spine density of pyramidal neurons from layers II/III. mPFC levels of GABA and glutamate neurotransmitters were not different between genotypes. Our results suggest that the 15q13.3 deletion modulates nonneuronal circuits in mPFC and confers molecular and morphometric alterations in the inhibitory and excitatory neurocircuits, respectively. These alterations potentially contribute to the phenotypes accompanied with the 15q13.3DS.
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Affiliation(s)
- Abdel-Rahman Al-Absi
- Center for Molecular Morphology, Section for Stereology and Microscopy, Center for Stochastic Geometry and Advanced Bioimaging, Department of Clinical Medicine, Aarhus University, 8000 Aarhus, Denmark
| | - Per Qvist
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark.,The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, 8210 Aarhus, Denmark.,Centre for Integrative Sequencing, iSEQ, Aarhus University, 8000 Aarhus, Denmark.,Center for Genomics and Personalized Medicine, CGPM, Aarhus University, 8000 Aarhus, Denmark
| | - Simon Glerup
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark
| | - Connie Sanchez
- Translational Neuropsychiatry Unit, Aarhus University, 8000 Aarhus, Denmark
| | - Jens R Nyengaard
- Center for Molecular Morphology, Section for Stereology and Microscopy, Center for Stochastic Geometry and Advanced Bioimaging, Department of Clinical Medicine, Aarhus University, 8000 Aarhus, Denmark
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5
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Deshmukh AL, Porro A, Mohiuddin M, Lanni S, Panigrahi GB, Caron MC, Masson JY, Sartori AA, Pearson CE. FAN1, a DNA Repair Nuclease, as a Modifier of Repeat Expansion Disorders. J Huntingtons Dis 2021; 10:95-122. [PMID: 33579867 PMCID: PMC7990447 DOI: 10.3233/jhd-200448] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
FAN1 encodes a DNA repair nuclease. Genetic deficiencies, copy number variants, and single nucleotide variants of FAN1 have been linked to karyomegalic interstitial nephritis, 15q13.3 microdeletion/microduplication syndrome (autism, schizophrenia, and epilepsy), cancer, and most recently repeat expansion diseases. For seven CAG repeat expansion diseases (Huntington's disease (HD) and certain spinocerebellar ataxias), modification of age of onset is linked to variants of specific DNA repair proteins. FAN1 variants are the strongest modifiers. Non-coding disease-delaying FAN1 variants and coding disease-hastening variants (p.R507H and p.R377W) are known, where the former may lead to increased FAN1 levels and the latter have unknown effects upon FAN1 functions. Current thoughts are that ongoing repeat expansions in disease-vulnerable tissues, as individuals age, promote disease onset. Fan1 is required to suppress against high levels of ongoing somatic CAG and CGG repeat expansions in tissues of HD and FMR1 transgenic mice respectively, in addition to participating in DNA interstrand crosslink repair. FAN1 is also a modifier of autism, schizophrenia, and epilepsy. Coupled with the association of these diseases with repeat expansions, this suggests a common mechanism, by which FAN1 modifies repeat diseases. Yet how any of the FAN1 variants modify disease is unknown. Here, we review FAN1 variants, associated clinical effects, protein structure, and the enzyme's attributed functional roles. We highlight how variants may alter its activities in DNA damage response and/or repeat instability. A thorough awareness of the FAN1 gene and FAN1 protein functions will reveal if and how it may be targeted for clinical benefit.
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Affiliation(s)
- Amit L. Deshmukh
- Program of Genetics & Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, Ontario, Canada
| | - Antonio Porro
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Mohiuddin Mohiuddin
- Program of Genetics & Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, Ontario, Canada
| | - Stella Lanni
- Program of Genetics & Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, Ontario, Canada
| | - Gagan B. Panigrahi
- Program of Genetics & Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, Ontario, Canada
| | - Marie-Christine Caron
- Department of Molecular Biology, Medical Biochemistry and Pathology; Laval University Cancer Research Center, Québec City, Quebec, Canada
- Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Division, Québec City, Quebec, Canada
| | - Jean-Yves Masson
- Department of Molecular Biology, Medical Biochemistry and Pathology; Laval University Cancer Research Center, Québec City, Quebec, Canada
- Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Division, Québec City, Quebec, Canada
| | | | - Christopher E. Pearson
- Program of Genetics & Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, Ontario, Canada
- University of Toronto, Program of Molecular Genetics, Toronto, Ontario, Canada
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6
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Suzuki H, Inaba M, Yamada M, Uehara T, Takenouchi T, Mizuno S, Kosaki K, Doi M. Biallelic loss of OTUD7A causes severe muscular hypotonia, intellectual disability, and seizures. Am J Med Genet A 2020; 185:1182-1186. [PMID: 33381903 DOI: 10.1002/ajmg.a.62054] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 11/13/2020] [Accepted: 12/02/2020] [Indexed: 02/02/2023]
Abstract
The heterozygous deletion of 15q13.3 is a recurrently observed microdeletion syndrome associated with a relatively mild phenotype including learning disability and language impairment. In contrast, the homozygous deletion of 15q13.3 is extremely rare and is associated with a much severer phenotype that includes epileptic encephalopathy, profound intellectual disability, and hypotonia. Which of the genes within the deleted interval is responsible for the more severe features when biallelically deleted is currently unknown. Here, we report a patient with profound hypotonia, severe intellectual disability, and seizures who had biallelic loss-of-function variants in OTUD7A: a 15q13.3 deletion including the OTUD7A locus, and a frameshift OTUD7A variant c.1125del, p.(Glu375Aspfs*11). Unexpectedly, both aberrations occurred de novo. Our experiment using Caenorhabditis elegans showed that worms carrying a corresponding homozygous variant in the homolog OTUB-2 exhibited weakened muscle contraction suggestive of aberrant neuromuscular transmission. We concluded that the biallelic complete loss of OTUD7A in humans represents a presumably new autosomal recessive disorder characterized by profound hypotonia, severe intellectual disability, and seizures.
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Affiliation(s)
- Hisato Suzuki
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan
| | - Mie Inaba
- Department of Clinical Genetics, Aichi Developmental Disability Center Central Hospital, Aichi, Japan
| | - Mamiko Yamada
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan
| | - Tomoko Uehara
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan.,Department of Clinical Genetics, Aichi Developmental Disability Center Central Hospital, Aichi, Japan
| | - Toshiki Takenouchi
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
| | - Seiji Mizuno
- Department of Clinical Genetics, Aichi Developmental Disability Center Central Hospital, Aichi, Japan
| | - Kenjiro Kosaki
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan
| | - Motomichi Doi
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki, Japan
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7
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Molecular, physiological and behavioral characterization of the heterozygous Df[h15q13]/+ mouse model associated with the human 15q13.3 microdeletion syndrome. Brain Res 2020; 1746:147024. [PMID: 32712126 DOI: 10.1016/j.brainres.2020.147024] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 07/13/2020] [Accepted: 07/18/2020] [Indexed: 12/29/2022]
Abstract
The human 15q13.3 microdeletion syndrome (DS) is caused by a heterozygous microdeletion (MD) affecting six genes: FAN1; MTMR10; TRPM1; KLF13; OTUD7A; and CHRNA7. Carriers are at risk for intellectual disability, epilepsy, autism spectrum disorder, and schizophrenia. Here we used the Df[h15q13]/+ mouse model with an orthologous deletion to further characterize molecular, neurophysiological, and behavioral parameters that are relevant to the 15q13.3 DS. First, we verified the expression and distribution of the α7 nicotinic acetylcholine receptor (nAChR), a gene product of the CHRNA7, in cortical and subcortical areas. Results revealed similar mRNA distribution pattern in wildtype (WT) and heterozygous (Het) mice, with about half the number of α7 nAChR binding sites in mutants. Hippocampal recordings showed similar input/output responses of field excitatory post-synaptic potentials and theta-burst induced long-term potentiation in WT and Het mice. Het males exhibited impaired spatial learning acquisition in the Barnes Maze. Indicative of increased seizure susceptibility, Het mice developed secondary seizures after 6-Hz corneal stimulation, and had significantly increased sensitivity to the chemoconvulsant pentylenetetrazol resulting in increased spiking in hippocampal EEG recordings. Basal mRNA expression of brain derived neurotrophic factor and activity regulated immediate early genes (c-fos, Arc, Erg-1 and Npas4) during adolescence, a critical period of brain maturation, was unaffected by genotype. Thus, the MD did not show gross neuroanatomical, molecular, and neurophysiological abnormalities despite deficits in spatial learning and increased susceptibility to seizures. Altogether, our results verify the phenotypic profile of the heterozygous Df[h15q13]/+ mouse model and underscore its translational relevance for human 15q13.3 DS.
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8
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Ganeshpurkar A, Singh R, Kumar D, Divya, Shivhare S, Kumar A, Singh SK. Computational binding study with α7 nicotinic acetylcholine receptor of Anvylic-3288: an allosteric modulator. MOLECULAR SIMULATION 2020. [DOI: 10.1080/08927022.2020.1795166] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Ankit Ganeshpurkar
- Pharmaceutical Chemistry Research Laboratory, Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
| | - Ravi Singh
- Pharmaceutical Chemistry Research Laboratory, Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
| | - Devendra Kumar
- Pharmaceutical Chemistry Research Laboratory, Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
| | - Divya
- Pharmaceutical Chemistry Research Laboratory, Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
| | - Shalini Shivhare
- Pharmaceutical Chemistry Research Laboratory, Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
| | - Ashok Kumar
- Pharmaceutical Chemistry Research Laboratory, Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
| | - Sushil Kumar Singh
- Pharmaceutical Chemistry Research Laboratory, Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
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9
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Simon J, Stoll K, Fick R, Mott J, Lawson‐Yuen A. Homozygous 15q13.3 microdeletion in a child with hypotonia and impaired vision: A new report and review of the literature. Clin Case Rep 2019; 7:2311-2315. [PMID: 31893048 PMCID: PMC6935653 DOI: 10.1002/ccr3.2403] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 07/11/2019] [Accepted: 07/29/2019] [Indexed: 11/08/2022] Open
Abstract
Although there are numerous reports of heterozygous 15q13.3 microdeletion, homozygous 15q13.3 microdeletion is rare. We report a new patient with homozygous microdeletion of 15q13.2q13.3 and review the previous literature reports. Common clinical features include encephalopathy, hypotonia, developmental delay, cortical vision impairment, optic nerve abnormality, epilepsy, and abnormal electroencephalogram (EEG) findings.
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Affiliation(s)
| | | | - Roger Fick
- Genomics InstituteMary Bridge Children's Hospital, MultiCare Health SystemTacomaWashington
| | - Jared Mott
- Department of Pediatric NeurologyMary Bridge Children's Hospital, MultiCare Health SystemTacomaWashington
| | - Amy Lawson‐Yuen
- Genomics InstituteMary Bridge Children's Hospital, MultiCare Health SystemTacomaWashington
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10
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Felix RA, Chavez VA, Novicio DM, Morley BJ, Portfors CV. Nicotinic acetylcholine receptor subunit α 7-knockout mice exhibit degraded auditory temporal processing. J Neurophysiol 2019; 122:451-465. [PMID: 31116647 DOI: 10.1152/jn.00170.2019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The CHRNA7 gene that encodes the α7-subunit of the nicotinic acetylcholine receptor (α7-nAChR) has been associated with some autism spectrum disorders and other neurodevelopmental conditions characterized, in part, by auditory and language impairment. These conditions may include auditory processing disorders that represent impaired timing of neural activity, often accompanied by problems understanding speech. Here, we measure timing properties of sound-evoked activity via the auditory brainstem response (ABR) of α7-nAChR knockout mice of both sexes and wild-type colony controls. We find a significant timing delay in evoked ABR signals that represents midbrain activity in knockouts. We also examine spike-timing properties of neurons in the inferior colliculus, a midbrain nucleus that exhibits high levels of α7-nAChR during development. We find delays of evoked responses along with degraded spiking precision in knockout animals. We find similar timing deficits in responses of neurons in the superior paraolivary nucleus and ventral nucleus of the lateral lemniscus, which are brainstem nuclei thought to shape temporal precision in the midbrain. In addition, we find that other measures of temporal acuity including forward masking and gap detection are impaired for knockout animals. We conclude that altered temporal processing at the level of the brainstem in α7-nAChR-deficient mice may contribute to degraded spike timing in the midbrain, which may underlie the observed timing delay in the ABR signals. Our findings are consistent with a role for the α7-nAChR in types of neurodevelopmental and auditory processing disorders and we identify potential neural targets for intervention.NEW & NOTEWORTHY Disrupted signaling via the α7-nicotinic acetylcholine receptor (α7-nAChR) is associated with neurodevelopmental disorders that include impaired auditory processing. The underlying causes of dysfunction are not known but a common feature is abnormal timing of neural activity. We examined temporal processing of α7-nAChR knockout mice and wild-type controls. We found degraded spike timing of neurons in knockout animals, which manifests at the level of the auditory brainstem and midbrain.
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Affiliation(s)
- Richard A Felix
- School of Biological Sciences and the Department of Integrated Physiology and Neuroscience, Washington State University Vancouver, Vancouver, Washington
| | - Vicente A Chavez
- School of Biological Sciences and the Department of Integrated Physiology and Neuroscience, Washington State University Vancouver, Vancouver, Washington
| | - Dyana M Novicio
- School of Biological Sciences and the Department of Integrated Physiology and Neuroscience, Washington State University Vancouver, Vancouver, Washington
| | | | - Christine V Portfors
- School of Biological Sciences and the Department of Integrated Physiology and Neuroscience, Washington State University Vancouver, Vancouver, Washington
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11
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Alsagob M, Salih MA, Hamad MHA, Al-Yafee Y, Al-Zahrani J, Al-Bakheet A, Nester M, Sakati N, Wakil SM, AlOdaib A, Colak D, Kaya N. First report of two successive deletions on chromosome 15q13 cytogenetic bands in a boy and girl: additional data to 15q13.3 syndrome with a report of high IQ patient. Mol Cytogenet 2019; 12:21. [PMID: 31131027 PMCID: PMC6525444 DOI: 10.1186/s13039-019-0432-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 05/01/2019] [Indexed: 11/10/2022] Open
Abstract
15q13.3 syndrome is associated with a wide spectrum of neurological disorders. Among a cohort of 150 neurodevelopmental cases, we identified two patients with two close proximity interstitial hemizygous deletions on chromosome 15q13. Using high-density microarrays, we characterized these deletions and their approximate breakpoints. The second deletion in both patients overlaps in a small area containing CHRNA7 where the gene is partially deleted. The CHRNA7 is considered a strong candidate for the 15q13.3 deletion syndrome's pathogenicity. Patient 1 has cognitive impairment, learning disabilities, hyperactivity and subtle dysmorphic features whereas patient 2 has mild language impairment with speech difficulty, mild dysmorphia, heart defect and interestingly a high IQ that has not been reported in 15q13.3 syndrome patients before. Our study presents first report of such two successive deletions in 15q13.3 syndrome patients and a high IQ in a 15q13.3 syndrome patient. Our study expands the breakpoints and phenotypic features related to 15q13.3 syndrome.
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Affiliation(s)
- Maysoon Alsagob
- 1Department of Genetics, King Faisal Specialist Hospital and Research Centre, MBC: 03, Riyadh, 11211 Kingdom of Saudi Arabia
| | - Mustafa A Salih
- 2Division of Pediatric Neurology, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Muddathir H A Hamad
- 2Division of Pediatric Neurology, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Yusra Al-Yafee
- 1Department of Genetics, King Faisal Specialist Hospital and Research Centre, MBC: 03, Riyadh, 11211 Kingdom of Saudi Arabia
| | - Jawaher Al-Zahrani
- 1Department of Genetics, King Faisal Specialist Hospital and Research Centre, MBC: 03, Riyadh, 11211 Kingdom of Saudi Arabia
| | - Albandary Al-Bakheet
- 1Department of Genetics, King Faisal Specialist Hospital and Research Centre, MBC: 03, Riyadh, 11211 Kingdom of Saudi Arabia
| | - Michael Nester
- 3Department of Neurosciences, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Nadia Sakati
- 3Department of Neurosciences, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Salma M Wakil
- 1Department of Genetics, King Faisal Specialist Hospital and Research Centre, MBC: 03, Riyadh, 11211 Kingdom of Saudi Arabia
| | - Ali AlOdaib
- 1Department of Genetics, King Faisal Specialist Hospital and Research Centre, MBC: 03, Riyadh, 11211 Kingdom of Saudi Arabia
| | - Dilek Colak
- 4Department of Biostatistics, Epidemiology, and Scientific Computing, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Namik Kaya
- 1Department of Genetics, King Faisal Specialist Hospital and Research Centre, MBC: 03, Riyadh, 11211 Kingdom of Saudi Arabia.,2Division of Pediatric Neurology, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
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Yin J, Chen W, Chao ES, Soriano S, Wang L, Wang W, Cummock SE, Tao H, Pang K, Liu Z, Pereira FA, Samaco RC, Zoghbi HY, Xue M, Schaaf CP. Otud7a Knockout Mice Recapitulate Many Neurological Features of 15q13.3 Microdeletion Syndrome. Am J Hum Genet 2018; 102:296-308. [PMID: 29395075 DOI: 10.1016/j.ajhg.2018.01.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 01/10/2018] [Indexed: 10/18/2022] Open
Abstract
15q13.3 microdeletion syndrome is characterized by a wide spectrum of neurodevelopmental disorders, including developmental delay, intellectual disability, epilepsy, language impairment, abnormal behaviors, neuropsychiatric disorders, and hypotonia. This syndrome is caused by a deletion on chromosome 15q, which typically encompasses six genes. Here, through studies on OTU deubiquitinase 7A (Otud7a) knockout mice, we identify OTUD7A as a critical gene responsible for many of the cardinal phenotypes associated with 15q13.3 microdeletion syndrome. Otud7a-null mice show reduced body weight, developmental delay, abnormal electroencephalography patterns and seizures, reduced ultrasonic vocalizations, decreased grip strength, impaired motor learning/motor coordination, and reduced acoustic startle. We show that OTUD7A localizes to dendritic spines and that Otud7a-null mice have decreased dendritic spine density compared to their wild-type littermates. Furthermore, frequency of miniature excitatory postsynaptic currents (mEPSCs) is reduced in the frontal cortex of Otud7a-null mice, suggesting a role of Otud7a in regulation of dendritic spine density and glutamatergic synaptic transmission. Taken together, our results suggest decreased OTUD7A dosage as a major contributor to the neurodevelopmental phenotypes associated with 15q13.3 microdeletion syndrome, through the misregulation of dendritic spine density and activity.
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Gillentine MA, Yin J, Bajic A, Zhang P, Cummock S, Kim JJ, Schaaf CP. Functional Consequences of CHRNA7 Copy-Number Alterations in Induced Pluripotent Stem Cells and Neural Progenitor Cells. Am J Hum Genet 2017; 101:874-887. [PMID: 29129316 DOI: 10.1016/j.ajhg.2017.09.024] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 09/27/2017] [Indexed: 01/08/2023] Open
Abstract
Copy-number variants (CNVs) of chromosome 15q13.3 manifest clinically as neuropsychiatric disorders with variable expressivity. CHRNA7, encoding for the α7 nicotinic acetylcholine receptor (nAChR), has been suggested as a candidate gene for the phenotypes observed. Here, we used induced pluripotent stem cells (iPSCs) and neural progenitor cells (NPCs) derived from individuals with heterozygous 15q13.3 deletions and heterozygous 15q13.3 duplications to investigate the CHRNA7-dependent molecular consequences of the respective CNVs. Unexpectedly, both deletions and duplications lead to decreased α7 nAChR-associated calcium flux. For deletions, this decrease in α7 nAChR-dependent calcium flux is expected due to haploinsufficiency of CHRNA7. For duplications, we found that increased expression of CHRNA7 mRNA is associated with higher expression of nAChR-specific and resident ER chaperones, indicating increased ER stress. This is likely a consequence of inefficient chaperoning and accumulation of α7 subunits in the ER, as opposed to being incorporated into functional α7 nAChRs at the cell membrane. Here, we showed that α7 nAChR-dependent calcium signal cascades are downregulated in both 15q13.3 deletion and duplication NPCs. While it may seem surprising that genomic changes in opposite direction have consequences on downstream pathways that are in similar direction, it aligns with clinical data, which suggest that both individuals with deletions and duplications of 15q13.3 manifest neuropsychiatric disease and cognitive deficits.
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Iha HA, Kunisawa N, Shimizu S, Tokudome K, Mukai T, Kinboshi M, Ikeda A, Ito H, Serikawa T, Ohno Y. Nicotine Elicits Convulsive Seizures by Activating Amygdalar Neurons. Front Pharmacol 2017; 8:57. [PMID: 28232801 PMCID: PMC5298991 DOI: 10.3389/fphar.2017.00057] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 01/26/2017] [Indexed: 12/14/2022] Open
Abstract
Nicotinic acetylcholine (nACh) receptors are implicated in the pathogenesis of epileptic disorders; however, the mechanisms of nACh receptors in seizure generation remain unknown. Here, we performed behavioral and immunohistochemical studies in mice and rats to clarify the mechanisms underlying nicotine-induced seizures. Treatment of animals with nicotine (1–4 mg/kg, i.p.) produced motor excitement in a dose-dependent manner and elicited convulsive seizures at 3 and 4 mg/kg. The nicotine-induced seizures were abolished by a subtype non-selective nACh antagonist, mecamylamine (MEC). An α7 nACh antagonist, methyllycaconitine, also significantly inhibited nicotine-induced seizures whereas an α4β2 nACh antagonist, dihydro-β-erythroidine, affected only weakly. Topographical analysis of Fos protein expression, a biological marker of neural excitation, revealed that a convulsive dose (4 mg/kg) of nicotine region-specifically activated neurons in the piriform cortex, amygdala, medial habenula, paratenial thalamus, anterior hypothalamus and solitary nucleus among 48 brain regions examined, and this was also suppressed by MEC. In addition, electric lesioning of the amygdala, but not the piriform cortex, medial habenula and thalamus, specifically inhibited nicotine-induced seizures. Furthermore, microinjection of nicotine (100 and 300 μg/side) into the amygdala elicited convulsive seizures in a dose-related manner. The present results suggest that nicotine elicits convulsive seizures by activating amygdalar neurons mainly via α7 nACh receptors.
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Affiliation(s)
- Higor A Iha
- Laboratory of Pharmacology, Osaka University of Pharmaceutical Sciences Osaka, Japan
| | - Naofumi Kunisawa
- Laboratory of Pharmacology, Osaka University of Pharmaceutical Sciences Osaka, Japan
| | - Saki Shimizu
- Laboratory of Pharmacology, Osaka University of Pharmaceutical Sciences Osaka, Japan
| | - Kentaro Tokudome
- Laboratory of Pharmacology, Osaka University of Pharmaceutical Sciences Osaka, Japan
| | - Takahiro Mukai
- Laboratory of Pharmacology, Osaka University of Pharmaceutical Sciences Osaka, Japan
| | - Masato Kinboshi
- Laboratory of Pharmacology, Osaka University of Pharmaceutical SciencesOsaka, Japan; Department of Epilepsy, Movement Disorders and Physiology, Graduate School of Medicine, Kyoto UniversityKyoto, Japan; Department of Neurology, Graduate School of Medicine, Wakayama Medical UniversityWakayama, Japan
| | - Akio Ikeda
- Department of Epilepsy, Movement Disorders and Physiology, Graduate School of Medicine, Kyoto University Kyoto, Japan
| | - Hidefumi Ito
- Department of Neurology, Graduate School of Medicine, Wakayama Medical University Wakayama, Japan
| | - Tadao Serikawa
- Laboratory of Pharmacology, Osaka University of Pharmaceutical Sciences Osaka, Japan
| | - Yukihiro Ohno
- Laboratory of Pharmacology, Osaka University of Pharmaceutical Sciences Osaka, Japan
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15
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Chrna7 deficient mice manifest no consistent neuropsychiatric and behavioral phenotypes. Sci Rep 2017; 7:39941. [PMID: 28045139 PMCID: PMC5206704 DOI: 10.1038/srep39941] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 11/28/2016] [Indexed: 11/22/2022] Open
Abstract
The alpha7 nicotinic acetylcholine receptor, encoded by the CHRNA7 gene, has been implicated in various psychiatric and behavioral disorders, including schizophrenia, bipolar disorder, epilepsy, autism, Alzheimer’s disease, and Parkinson’s disease, and is considered a potential target for therapeutic intervention. 15q13.3 microdeletion syndrome is a rare genetic disorder, caused by submicroscopic deletions on chromosome 15q. CHRNA7 is the only gene in this locus that has been deleted entirely in cases involving the smallest microdeletions. Affected individuals manifest variable neurological and behavioral phenotypes, which commonly include developmental delay/intellectual disability, epilepsy, and autism spectrum disorder. Subsets of patients have short attention spans, aggressive behaviors, mood disorders, or schizophrenia. Previous behavioral studies suggested that Chrna7 deficient mice had attention deficits, but were normal in baseline behavioral responses, learning, memory, and sensorimotor gating. Given a growing interest in CHRNA7-related diseases and a better appreciation of its associated human phenotypes, an in-depth behavioral characterization of the Chrna7 deficient mouse model appeared prudent. This study was designed to investigate whether Chrna7 deficient mice manifest phenotypes related to those seen in human individuals, using an array of 12 behavioral assessments and electroencephalogram (EEG) recordings on freely-moving mice. Examined phenotypes included social interaction, compulsive behaviors, aggression, hyperactivity, anxiety, depression, and somatosensory gating. Our data suggests that mouse behavior and EEG recordings are not sensitive to decreased Chrna7 copy number.
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16
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Ziats MN, Goin-Kochel RP, Berry LN, Ali M, Ge J, Guffey D, Rosenfeld JA, Bader P, Gambello MJ, Wolf V, Penney LS, Miller R, Lebel RR, Kane J, Bachman K, Troxell R, Clark G, Minard CG, Stankiewicz P, Beaudet A, Schaaf CP. The complex behavioral phenotype of 15q13.3 microdeletion syndrome. Genet Med 2016; 18:1111-1118. [PMID: 26963284 DOI: 10.1038/gim.2016.9] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 01/09/2016] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Chromosome 15q13.3 represents a hotspot for genomic rearrangements due to repetitive sequences mediating nonallelic homologous recombination. Deletions of 15q13.3 have been identified in the context of multiple neurological and psychiatric disorders, but a prospective clinical and behavioral assessment of affected individuals has not yet been reported. METHODS Eighteen subjects with 15q13.3 microdeletion underwent a series of behavioral assessments, along with clinical history and physical examination, to comprehensively define their behavioral phenotypes. RESULTS Cognitive deficits are the most prevalent feature in 15q13.3 deletion syndrome, with an average nonverbal IQ of 60 among the patients studied. Autism spectrum disorder was highly penetrant, with 31% of patients meeting clinical criteria and exceeding cutoff scores on both ADOS-2 and ADI-R. Affected individuals exhibited a complex pattern of behavioral abnormalities, most notably hyperactivity, attention problems, withdrawal, and externalizing symptoms, as well as impairments in functional communication, leadership, adaptive skills, and activities of daily living. CONCLUSIONS The 15q13.3 deletion syndrome encompasses a heterogeneous behavioral phenotype that poses a major challenge to parents, caregivers, and treating providers. Further work to more clearly delineate genotype-phenotype relationships in 15q13.3 deletions will be important for anticipatory guidance and development of targeted therapies.Genet Med 18 11, 1111-1118.
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Affiliation(s)
- Mark N Ziats
- Medical Scientist Training Program, Baylor College of Medicine, Houston, Texas, USA
| | - Robin P Goin-Kochel
- Autism Center, Texas Children's Hospital, Houston, Texas, USA.,Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Leandra N Berry
- Autism Center, Texas Children's Hospital, Houston, Texas, USA.,Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - May Ali
- Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, USA
| | - Jun Ge
- Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Danielle Guffey
- Dan L. Duncan Institute for Clinical and Translational Research, Baylor College of Medicine, Houston, Texas, USA
| | - Jill A Rosenfeld
- Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | | | - Michael J Gambello
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Varina Wolf
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Lynette S Penney
- Department of Pediatrics, IWK Health Centre, Halifax, Nova Scotia, Canada
| | - Ryan Miller
- Section of Medical Genetics, Department of Pediatrics, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Robert Roger Lebel
- Section of Medical Genetics, Department of Pediatrics, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Jeffrey Kane
- 'Specially for Children Medical Group, Austin, Texas, USA
| | - Kristine Bachman
- Department of Pediatrics, Geisinger Medical Center, Danville, Pennsylvania, USA
| | | | - Gary Clark
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Charles G Minard
- Dan L. Duncan Institute for Clinical and Translational Research, Baylor College of Medicine, Houston, Texas, USA
| | - Pawel Stankiewicz
- Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Arthur Beaudet
- Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Christian P Schaaf
- Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, USA
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17
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Deutsch SI, Burket JA, Benson AD, Urbano MR. The 15q13.3 deletion syndrome: Deficient α(7)-containing nicotinic acetylcholine receptor-mediated neurotransmission in the pathogenesis of neurodevelopmental disorders. Prog Neuropsychopharmacol Biol Psychiatry 2016; 64:109-17. [PMID: 26257138 DOI: 10.1016/j.pnpbp.2015.08.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 08/03/2015] [Accepted: 08/04/2015] [Indexed: 11/15/2022]
Abstract
Array comparative genomic hybridization (array CGH) has led to the identification of microdeletions of the proximal region of chromosome 15q between breakpoints (BP) 3 or BP4 and BP5 encompassing CHRNA7, the gene encoding the α7-nicotinic acetylcholine receptor (α7nAChR) subunit. Phenotypic manifestations of persons with these microdeletions are variable and some heterozygous carriers are seemingly unaffected, consistent with their variable expressivity and incomplete penetrance. Nonetheless, the 15q13.3 deletion syndrome is associated with several neuropsychiatric disorders, including idiopathic generalized epilepsy, intellectual disability, autism spectrum disorders (ASDs) and schizophrenia. Haploinsufficient expression of CHRNA7 in this syndrome has highlighted important roles the α7nAChR plays in the developing brain and normal processes of attention, cognition, memory and behavior throughout life. Importantly, the existence of the 15q13.3 deletion syndrome contributes to an emerging literature supporting clinical trials therapeutically targeting the α7nAChR in disorders such as ASDs and schizophrenia, including the larger population of patients with no evidence of haploinsufficient expression of CHRNA7. Translational clinical trials will be facilitated by the existence of positive allosteric modulators (PAMs) of the α7nAChR that act at sites on the receptor distinct from the orthosteric site that binds acetylcholine and choline, the receptor's endogenous ligands. PAMs lack intrinsic efficacy by themselves, but act where and when the endogenous ligands are released in response to relevant social and cognitive provocations to increase the likelihood they will result in α7nAChR ion channel activation.
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Affiliation(s)
- Stephen I Deutsch
- Department of Psychiatry and Behavioral Sciences, Eastern Virginia Medical School, 825 Fairfax Avenue, Suite 710, Norfolk, VA 23507-1912, United States.
| | - Jessica A Burket
- Department of Psychiatry and Behavioral Sciences, Eastern Virginia Medical School, 825 Fairfax Avenue, Suite 710, Norfolk, VA 23507-1912, United States
| | - Andrew D Benson
- Department of Psychiatry and Behavioral Sciences, Eastern Virginia Medical School, 825 Fairfax Avenue, Suite 710, Norfolk, VA 23507-1912, United States
| | - Maria R Urbano
- Department of Psychiatry and Behavioral Sciences, Eastern Virginia Medical School, 825 Fairfax Avenue, Suite 710, Norfolk, VA 23507-1912, United States
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18
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Xie Y. Is Chromosome 15q13.3 Duplication Involving CHRNA7 Associated With Oral Clefts? Child Neurol Open 2015; 2:2329048X15618918. [PMID: 28503599 PMCID: PMC5417031 DOI: 10.1177/2329048x15618918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Revised: 10/17/2015] [Accepted: 10/27/2015] [Indexed: 11/15/2022] Open
Abstract
Copy number variants have been associated with intellectual disability, multiple congenital anomalies and craniofacial disorders. It has been reported that microduplication of 15q13.3 is associated with autism, cognitive impairment, seizures, and attention-deficit hyperactivity disorder. Here, the author identified microduplications in the 15q13.3 region in 4 cases from 3 Chinese families using chromosomal microarray analysis-single nucleotide polymorphism array (CMA-SNP). These 4 cases include 2 fetuses from 2 unrelated families and a father and a daughter from a third family. The identified microduplications of 15q13.3 are approximately 400 kb in size, encompassing just 1 gene, cholinergic receptor, neuronal nicotinic, alpha polypeptide 7 (CHRNA7). Three-fourths of the probands exhibit oral clefts, which has not been previously reported in cases with this duplication genotype. Therefore, in this study, the author describes for the first time the common feature of oral clefts in patients carrying a microduplication of 15q13.3 encompassing the CHRNA7 gene, which sheds light on the correlation between CHRNA7 and cleft palate.
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Affiliation(s)
- Yingjun Xie
- Department of Prenatal Diagnosis, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.,Key Laboratory for Major Obstetric Diseases of Guangdong Province, Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
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19
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Damiano JA, Mullen SA, Hildebrand MS, Bellows ST, Lawrence KM, Arsov T, Dibbens L, Major H, Dahl HHM, Mefford HC, Darbro BW, Scheffer IE, Berkovic SF. Evaluation of multiple putative risk alleles within the 15q13.3 region for genetic generalized epilepsy. Epilepsy Res 2015; 117:70-3. [DOI: 10.1016/j.eplepsyres.2015.09.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 08/28/2015] [Accepted: 09/07/2015] [Indexed: 12/11/2022]
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20
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John D, Berg DK. Long-lasting changes in neural networks to compensate for altered nicotinic input. Biochem Pharmacol 2015; 97:418-424. [PMID: 26206188 PMCID: PMC4600434 DOI: 10.1016/j.bcp.2015.07.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Accepted: 07/07/2015] [Indexed: 11/21/2022]
Abstract
The nervous system must balance excitatory and inhibitory input to constrain network activity levels within a proper dynamic range. This is a demanding requirement during development, when networks form and throughout adulthood as networks respond to constantly changing environments. Defects in the ability to sustain a proper balance of excitatory and inhibitory activity are characteristic of numerous neurological disorders such as schizophrenia, Alzheimer's disease, and autism. A variety of homeostatic mechanisms appear to be critical for balancing excitatory and inhibitory activity in a network. These are operative at the level of individual neurons, regulating their excitability by adjusting the numbers and types of ion channels, and at the level of synaptic connections, determining the relative numbers of excitatory versus inhibitory connections a neuron receives. Nicotinic cholinergic signaling is well positioned to contribute at both levels because it appears early in development, extends across much of the nervous system, and modulates transmission at many kinds of synapses. Further, it is known to influence the ratio of excitatory-to-inhibitory synapses formed on neurons during development. GABAergic inhibitory neurons are likely to be key for maintaining network homeostasis (limiting excitatory output), and nicotinic signaling is known to prominently regulate the activity of several GABAergic neuronal subtypes. But how nicotinic signaling achieves this and how networks may compensate for the loss of such input are important questions remaining unanswered. These issues are reviewed.
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Affiliation(s)
- Danielle John
- Neurobiology Section, Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093-0357, United States; Kavli Institute for Brain and Mind, University of California, San Diego, La Jolla, CA 92093-0357, United States
| | - Darwin K Berg
- Neurobiology Section, Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093-0357, United States; Kavli Institute for Brain and Mind, University of California, San Diego, La Jolla, CA 92093-0357, United States.
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21
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Bertrand D, Lee CHL, Flood D, Marger F, Donnelly-Roberts D. Therapeutic Potential of α7 Nicotinic Acetylcholine Receptors. Pharmacol Rev 2015; 67:1025-73. [DOI: 10.1124/pr.113.008581] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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22
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Hu J, Liao J, Sathanoori M, Kochmar S, Sebastian J, Yatsenko SA, Surti U. CNTN6 copy number variations in 14 patients: a possible candidate gene for neurodevelopmental and neuropsychiatric disorders. J Neurodev Disord 2015; 7:26. [PMID: 26257835 PMCID: PMC4528395 DOI: 10.1186/s11689-015-9122-9] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 07/21/2015] [Indexed: 01/06/2023] Open
Abstract
Background Neurodevelopmental disorders are impairments of brain function that affect emotion, learning, and memory. Copy number variations of contactin genes (CNTNs), including CNTN3, CNTN4, CNTN5, and CNTN6, have been suggested to be associated with these disorders. However, phenotypes have been reported in only a handful of patients with copy number variations involving CNTNs. Methods From January 2009 to January 2013, 3724 patients ascertained through the University of Pittsburgh Medical Center were referred to our laboratory for clinical array comparative genomic hybridization testing. We screened this cohort of patients to identify individuals with the 3p26.3 copy number variations involving the CNTN6 gene, and then retrospectively reviewed the clinical information and family history of these patients to determine the association between the 3p26.3 copy number variations and neurodevelopmental disorders. Results Fourteen of the 3724 patients had 3p26.3 copy number variations involving the CNTN6 gene. Thirteen of the 14 patients with these CNTN6 copy number variations presented with various neurodevelopmental disorders including developmental delay, autistic spectrum disorders, seizures and attention deficit hyperactivity disorder. Family history was available for 13 of the 14 patients. Twelve of the thirteen families have multiple members with neurodevelopmental and neuropsychiatric disorders including attention deficit hyperactivity disorder, seizures, autism spectrum disorder, intellectual disability, schizophrenia, depression, anxiety, learning disability, and bipolar disorder. Conclusions Our findings suggest that deletion or duplication of the CNTN6 gene is associated with a wide spectrum of neurodevelopmental behavioral disorders.
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Affiliation(s)
- Jie Hu
- Pittsburgh Cytogenetics Laboratory, Center of Medical Genetics and Genomics, Magee-Womens Hospital of UPMC, Pittsburgh, PA 15213 USA ; Department of Obstetrics, Gynecology & Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213 USA
| | - Jun Liao
- Pittsburgh Cytogenetics Laboratory, Center of Medical Genetics and Genomics, Magee-Womens Hospital of UPMC, Pittsburgh, PA 15213 USA
| | - Malini Sathanoori
- Pittsburgh Cytogenetics Laboratory, Center of Medical Genetics and Genomics, Magee-Womens Hospital of UPMC, Pittsburgh, PA 15213 USA ; Department of Obstetrics, Gynecology & Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213 USA ; Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213 USA
| | - Sally Kochmar
- Pittsburgh Cytogenetics Laboratory, Center of Medical Genetics and Genomics, Magee-Womens Hospital of UPMC, Pittsburgh, PA 15213 USA
| | | | - Svetlana A Yatsenko
- Pittsburgh Cytogenetics Laboratory, Center of Medical Genetics and Genomics, Magee-Womens Hospital of UPMC, Pittsburgh, PA 15213 USA ; Department of Obstetrics, Gynecology & Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213 USA ; Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213 USA
| | - Urvashi Surti
- Pittsburgh Cytogenetics Laboratory, Center of Medical Genetics and Genomics, Magee-Womens Hospital of UPMC, Pittsburgh, PA 15213 USA ; Department of Obstetrics, Gynecology & Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213 USA ; Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213 USA
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23
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Gillentine MA, Schaaf CP. The human clinical phenotypes of altered CHRNA7 copy number. Biochem Pharmacol 2015; 97:352-362. [PMID: 26095975 DOI: 10.1016/j.bcp.2015.06.012] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 06/10/2015] [Indexed: 01/03/2023]
Abstract
Copy number variants (CNVs) have been implicated in multiple neuropsychiatric conditions, including autism spectrum disorder (ASD), schizophrenia, and intellectual disability (ID). Chromosome 15q13 is a hotspot for such CNVs due to the presence of low copy repeat (LCR) elements, which facilitate non-allelic homologous recombination (NAHR). Several of these CNVs have been overrepresented in individuals with neuropsychiatric disorders; yet variable expressivity and incomplete penetrance are commonly seen. Dosage sensitivity of the CHRNA7 gene, which encodes for the α7 nicotinic acetylcholine receptor in the human brain, has been proposed to have a major contribution to the observed cognitive and behavioral phenotypes, as it represents the smallest region of overlap to all the 15q13.3 deletions and duplications. Individuals with zero to four copies of CHRNA7 have been reported in the literature, and represent a range of clinical severity, with deletions causing generally more severe and more highly penetrant phenotypes. Potential mechanisms to account for the variable expressivity within each group of 15q13.3 CNVs will be discussed.
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Affiliation(s)
- Madelyn A Gillentine
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Christian P Schaaf
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, United States.
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24
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Lowther C, Costain G, Stavropoulos DJ, Melvin R, Silversides CK, Andrade DM, So J, Faghfoury H, Lionel AC, Marshall CR, Scherer SW, Bassett AS. Delineating the 15q13.3 microdeletion phenotype: a case series and comprehensive review of the literature. Genet Med 2014; 17:149-57. [PMID: 25077648 DOI: 10.1038/gim.2014.83] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 06/06/2014] [Indexed: 01/14/2023] Open
Abstract
PURPOSE Recurrent 15q13.3 deletions are enriched in multiple neurodevelopmental conditions including intellectual disability, autism, epilepsy, and schizophrenia. However, the 15q13.3 microdeletion syndrome remains ill-defined. METHODS We systematically compiled all cases of 15q13.3 deletion published before 2014. We also examined three locally available cohorts to identify new adults with 15q13.3 deletions. RESULTS We identified a total of 246 cases (133 children, 113 adults) with deletions overlapping or within the 15q13.3 (breakpoint (BP)4-BP5) region, including seven novel adult cases from local cohorts. No BP4-BP5 deletions were identified in 23,838 adult controls. Where known, 15q13.3 deletions were typically inherited (85.4%) and disproportionately of maternal origin (P < 0.0001). Overall, 198 cases (121 children, 77 adults; 80.5%) had at least one neuropsychiatric diagnosis. Accounting for ascertainment, developmental disability/intellectual disability was present in 57.7%, epilepsy/seizures in 28.0%, speech problems in 15.9%, autism spectrum disorder in 10.9%, schizophrenia in 10.2%, mood disorder in 10.2%, and attention deficit hyperactivity disorder in 6.5%. By contrast, major congenital malformations, including congenital heart disease (2.4%), were uncommon. Placenta previa occurred in the pregnancies of four cases. CONCLUSION The 15q13.3 microdeletion syndrome is predominantly characterized by neuropsychiatric expression. There are implications for pre- and postnatal detection, genetic counseling, and anticipatory care.
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Affiliation(s)
- Chelsea Lowther
- 1] Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto, Ontario, Canada [2] Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Gregory Costain
- Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Dimitri J Stavropoulos
- 1] Cytogenetics Laboratory, Department of Pediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada [2] Department of Laboratory Medicine and Pathology, University of Toronto, Toronto, Ontario, Canada
| | - Rebecca Melvin
- Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Candice K Silversides
- 1] Division of Cardiology, Department of Medicine, University Health Network, Toronto, Ontario, Canada [2] Division of Obstetric Medicine, Medical Disorders of Pregnancy Program, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Danielle M Andrade
- 1] Division of Neurology, Toronto Western Hospital, Toronto, Ontario, Canada [2] Krembil Neurosciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Joyce So
- 1] Department of Laboratory Medicine and Pathology, University of Toronto, Toronto, Ontario, Canada [2] Department of Clinical Genetics, Lakeridge Health Oshawa, Oshawa, Ontario, Canada
| | - Hanna Faghfoury
- The Fred A. Litwin and Family Centre in Genetic Medicine, University Health Network and Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Anath C Lionel
- 1] The Centre for Applied Genomics and Program in Genomics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada [2] Department of Molecular Genetics and McLaughlin Centre, University of Toronto, Toronto, Ontario, Canada
| | - Christian R Marshall
- 1] The Centre for Applied Genomics and Program in Genomics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada [2] Department of Molecular Genetics and McLaughlin Centre, University of Toronto, Toronto, Ontario, Canada
| | - Stephen W Scherer
- 1] Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada [2] The Centre for Applied Genomics and Program in Genomics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada [3] Department of Molecular Genetics and McLaughlin Centre, University of Toronto, Toronto, Ontario, Canada
| | - Anne S Bassett
- 1] Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto, Ontario, Canada [2] Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada [3] Division of Cardiology, Department of Medicine, University Health Network, Toronto, Ontario, Canada [4] Department of Psychiatry, University of Toronto and University Health Network, Toronto, Ontario, Canada
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25
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Lin H, Hsu FC, Baumann BH, Coulter DA, Anderson SA, Lynch DR. Cortical parvalbumin GABAergic deficits with α7 nicotinic acetylcholine receptor deletion: implications for schizophrenia. Mol Cell Neurosci 2014; 61:163-75. [PMID: 24983521 DOI: 10.1016/j.mcn.2014.06.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 05/23/2014] [Accepted: 06/16/2014] [Indexed: 11/25/2022] Open
Abstract
Dysfunction of cortical parvalbumin (PV)-containing GABAergic interneurons has been implicated in cognitive deficits of schizophrenia. In humans microdeletion of the CHRNA7 (α7 nicotinic acetylcholine receptor, nAChR) gene is associated with cortical dysfunction in a broad spectrum of neurodevelopmental and neuropsychiatric disorders including schizophrenia while in mice similar deletion causes analogous abnormalities including impaired attention, working-memory and learning. However, the pathophysiological roles of α7 nAChRs in cortical PV GABAergic development remain largely uncharacterized. In both in vivo and in vitro models, we identify here that deletion of the α7 nAChR gene in mice impairs cortical PV GABAergic development and recapitulates many of the characteristic neurochemical deficits in PV-positive GABAergic interneurons found in schizophrenia. α7 nAChR null mice had decreased cortical levels of GABAergic markers including PV, glutamic acid decarboxylase 65/67 (GAD65/67) and the α1 subunit of GABAA receptors, particularly reductions of PV and GAD67 levels in cortical PV-positive interneurons during late postnatal life and adulthood. Cortical GABAergic synaptic deficits were identified in the prefrontal cortex of α7 nAChR null mice and α7 nAChR null cortical cultures. Similar disruptions in development of PV-positive GABAergic interneurons and perisomatic synapses were found in cortical cultures lacking α7 nAChRs. Moreover, NMDA receptor expression was reduced in GABAergic interneurons, implicating NMDA receptor hypofunction in GABAergic deficits in α7 nAChR null mice. Our findings thus demonstrate impaired cortical PV GABAergic development and multiple characteristic neurochemical deficits reminiscent of schizophrenia in cortical PV-positive interneurons in α7 nAChR gene deletion models. This implicates crucial roles of α7 nAChRs in cortical PV GABAergic development and dysfunction in schizophrenia and other neuropsychiatric disorders.
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Affiliation(s)
- Hong Lin
- Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States; Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States
| | - Fu-Chun Hsu
- Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States; Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States
| | - Bailey H Baumann
- Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States; Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States
| | - Douglas A Coulter
- Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States; Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Stewart A Anderson
- Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States; Department of Child Psychiatry, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - David R Lynch
- Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States; Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States.
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Molas S, Dierssen M. The role of nicotinic receptors in shaping and functioning of the glutamatergic system: a window into cognitive pathology. Neurosci Biobehav Rev 2014; 46 Pt 2:315-25. [PMID: 24879992 DOI: 10.1016/j.neubiorev.2014.05.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 04/13/2014] [Accepted: 05/20/2014] [Indexed: 10/25/2022]
Abstract
The involvement of the cholinergic system in learning, memory and attention has long been recognized, although its neurobiological mechanisms are not fully understood. Recent evidence identifies the endogenous cholinergic signaling via nicotinic acetylcholine receptors (nAChRs) as key players in determining the morphological and functional maturation of the glutamatergic system. Here, we review the available experimental and clinical evidence of nAChRs contribution to the establishment of the glutamatergic system, and therefore to cognitive function. We provide some clues of the putative underlying molecular mechanisms and discuss recent human studies that associate genetic variability of the genes encoding nAChR subunits with cognitive disorders. Finally, we discuss the new avenues to therapeutically targeting nAChRs in persons with cognitive dysfunction for which the α7-nAChR subunit is an important etiological mechanism.
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Affiliation(s)
- Susanna Molas
- Systems Biology Program, Centre for Genomic Regulation (CRG), Barcelona E-08003, Spain; University Pompeu Fabra (UPF), Spain; CIBER de Enfermedades Raras (CIBERER), Barcelona E-08003, Spain
| | - Mara Dierssen
- Systems Biology Program, Centre for Genomic Regulation (CRG), Barcelona E-08003, Spain; University Pompeu Fabra (UPF), Spain; CIBER de Enfermedades Raras (CIBERER), Barcelona E-08003, Spain.
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27
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Clinical utility gene card for: 15q13.3 microdeletion syndrome. Eur J Hum Genet 2014; 22:ejhg201488. [PMID: 24824131 DOI: 10.1038/ejhg.2014.88] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 04/04/2014] [Accepted: 04/09/2014] [Indexed: 12/20/2022] Open
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Prasun P, Hankerd M, Kristofice M, Scussel L, Sivaswamy L, Ebrahim S. Compound heterozygous microdeletion of chromosome 15q13.3 region in a child with hypotonia, impaired vision, and global developmental delay. Am J Med Genet A 2014; 164A:1815-20. [PMID: 24700535 DOI: 10.1002/ajmg.a.36535] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 02/16/2014] [Indexed: 11/06/2022]
Abstract
Homozygous or compound heterozygous microdeletion of 15q13.3 region is a rare but clinically recognizable syndrome manifested by profound intellectual disability, muscular hypotonia, intractable seizures, and visual impairment. We identified a compound heterozygous 15q13.3 microdeletion in a 23-month-old girl with global developmental delay, generalized muscular hypotonia, and visual dysfunction. The larger deletion was approximately 1.28 Mb in size and contained seven genes including the TRPM1 and CHRNA7, while the smaller deletion was estimated to be 410 Kb in size and contained only CHRNA7. Compound heterozygous 15q13.3 microdeletion is extremely rare and to the best of our knowledge only two such patients have been reported in literature thus far. The findings in our patient suggest that the pathogenesis of visual dysfunction, which is a consistent finding in homozygous/compound heterozygous 15q13.3 microdeletion depends upon the size of microdeletion. Homozygous loss of TRPM1 likely causes retinal dysfunction while homozygous loss of CHRNA7 alone may lead to visual impairment by cortical mechanisms.
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Affiliation(s)
- Pankaj Prasun
- Division of Genetics & Metabolic Disorders, Department of Pediatrics, Wayne State University School of Medicine, Detroit, Michigan
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29
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Masurel-Paulet A, Drumare I, Holder M, Cuisset JM, Vallée L, Defoort S, Bourgois B, Pernes P, Cuvellier JC, Huet F, Chehadeh SE, Thevenon J, Callier P, Thauvin C, Faivre L, Andrieux J. Further delineation of eye manifestations in homozygous 15q13.3 microdeletions including TRPM1: a differential diagnosis of ceroid lipofuscinosis. Am J Med Genet A 2014; 164A:1537-44. [PMID: 24668847 DOI: 10.1002/ajmg.a.36471] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 12/31/2013] [Indexed: 11/11/2022]
Abstract
The 15q13.3 heterozygous microdeletion is a fairly common microdeletion syndrome with marked clinical variability and incomplete penetrance. The average size of the deletion, which comprises six genes including CHRNA7, is 1.5 Mb. CHRNA7 has been identified as the gene responsible for the neurological phenotype in this microdeletion syndrome. Only seven patients with a homozygous microdeletion that includes at least CHRNA7, and is inherited from both parents have been described in the literature. The aim of this study was to further describe the distinctive eye manifestations from the analysis in the three French patients diagnosed with the classical 1.5 Mb homozygous microdeletion. Patients' ages ranged from 30 months to 9 years, and included one sib pair. They all displayed a remarkably severe identifiable clinical phenotype that included congenital blindness and convulsive encephalopathy with inconstant abnormal movements. The ophthalmological examination revealed a lack of eye tracking, optic nerve pallor, an immature response with increased latencies with no response to the checkerboard stimulations at the visual evoked potential examination, and a distinctive retina dystrophy with a negative electroretinogram in which the "b" wave was smaller than the "a" wave after a dark adapted pupil and bright flash in all patients. Clear genotype-phenotype correlations emerged, showing that this eye phenotype was secondary to homozygous deletion of TRPM1, the gene responsible for autosomal recessive congenital stationary night blindness. The main differential diagnosis is ceroid lipofuscinosis.
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Affiliation(s)
- Alice Masurel-Paulet
- Centre de Génétique et Centre de Référence Anomalies du Développement et Syndromes Malformatifs, Hôpital d'Enfants, CHU Dijon, France
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30
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Schaaf CP. Nicotinic acetylcholine receptors in human genetic disease. Genet Med 2014; 16:649-56. [DOI: 10.1038/gim.2014.9] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 01/13/2014] [Indexed: 01/26/2023] Open
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Cortical synaptic NMDA receptor deficits in α7 nicotinic acetylcholine receptor gene deletion models: implications for neuropsychiatric diseases. Neurobiol Dis 2013; 63:129-40. [PMID: 24326163 DOI: 10.1016/j.nbd.2013.11.021] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 11/21/2013] [Accepted: 11/26/2013] [Indexed: 01/06/2023] Open
Abstract
Microdeletion of the human CHRNA7 gene (α7 nicotinic acetylcholine receptor, nAChR) as well as dysfunction in N-methyl-d-aspartate receptors (NMDARs) have been associated with cortical dysfunction in a broad spectrum of neurodevelopmental and neuropsychiatric disorders including schizophrenia. However, the pathophysiological roles of synaptic vs. extrasynaptic NMDARs and their interactions with α7 nAChRs in cortical dysfunction remain largely uncharacterized. Using a combination of in vivo and in vitro models, we demonstrate that α7 nAChR gene deletion leads to specific loss of synaptic NMDARs and their coagonist, d-serine, as well as glutamatergic synaptic deficits in mouse cortex. α7 nAChR null mice had decreased cortical NMDAR expression and glutamatergic synapse formation during postnatal development. Similar reductions in NMDAR expression and glutamatergic synapse formation were revealed in cortical cultures lacking α7 nAChRs. Interestingly, synaptic, but not extrasynaptic, NMDAR currents were specifically diminished in cultured cortical pyramidal neurons as well as in acute prefrontal cortical slices of α7 nAChR null mice. Moreover, d-serine responsive synaptic NMDAR-mediated currents and levels of the d-serine synthetic enzyme serine racemase were both reduced in α7 nAChR null cortical pyramidal neurons. Our findings thus identify specific loss of synaptic NMDARs and their coagonist, d-serine, as well as glutamatergic synaptic deficits in α7 nAChR gene deletion models of cortical dysfunction, thereby implicating α7 nAChR-mediated control of synaptic NMDARs and serine racemase/d-serine pathways in cortical dysfunction underlying many neuropsychiatric and neurodevelopmental disorders, particularly those associated with deletion of human CHRNA7.
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Melchior L, Bertelsen B, Debes NM, Groth C, Skov L, Mikkelsen JD, Brøndum-Nielsen K, Tümer Z. Microduplication of 15q13.3 and Xq21.31 in a family with Tourette syndrome and comorbidities. Am J Med Genet B Neuropsychiatr Genet 2013; 162B:825-31. [PMID: 23894120 DOI: 10.1002/ajmg.b.32186] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 06/26/2013] [Indexed: 12/31/2022]
Abstract
Tourette syndrome (TS) is a childhood onset neurodevelopmental disorder. Although it is widely accepted that genetic factors play a significant role in TS pathogenesis the etiology of this disorder is largely unknown. Identification of rare copy number variations (CNVs) as susceptibility factors in several neuropsychiatric disorders such as attention deficit-hyperactivity disorder (ADHD), autism and schizophrenia, suggests involvement of these rare structural changes also in TS etiology. In a male patient with TS, ADHD, and OCD (obsessive compulsive disorder) we identified two microduplications (at 15q13.3 and Xq21.31) inherited from a mother with subclinical ADHD. The 15q duplication included the CHRNA7 gene; while two genes, PABPC5 and PCDH11X, were within the Xq duplication. The Xq21.31 duplication was present in three brothers with TS including the proband, but not in an unaffected brother, whereas the 15q duplication was present only in the proband and his mother. The structural variations observed in this family may contribute to the observed symptoms, but further studies are necessary to investigate the possible involvement of the described variations in the TS etiology.
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Affiliation(s)
- Linea Melchior
- Applied Human Molecular Genetics, Kennedy Center, Copenhagen University Hospital, Rigshospitalet, Glostrup, Denmark
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Carvill GL, Mefford HC. Microdeletion syndromes. Curr Opin Genet Dev 2013; 23:232-9. [PMID: 23664828 DOI: 10.1016/j.gde.2013.03.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 03/11/2013] [Accepted: 03/25/2013] [Indexed: 01/11/2023]
Abstract
The recent explosion in the implementation of genome-wide microarray technology to discover rare, pathogenic genomic rearrangements in a variety of diseases has led to the discovery of numerous microdeletion syndromes. It is now clear that these microdeletions are associated with extensive phenotypic heterogeneity and incomplete penetrance. A subset of recurrent microdeletions underpin diverse phenotypes, including intellectual disability, autism, epilepsy and neuropsychiatric disorders. Recent studies highlight a role for additional low frequency variants, or 'second hits' to account for this variability. The implementation of massively parallel sequencing and epigenetic models may provide a powerful prospective approach to the delineation of microdeletion syndrome phenotypes.
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Affiliation(s)
- Gemma L Carvill
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
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Imbrici P, Camerino DC, Tricarico D. Major channels involved in neuropsychiatric disorders and therapeutic perspectives. Front Genet 2013; 4:76. [PMID: 23675382 PMCID: PMC3646240 DOI: 10.3389/fgene.2013.00076] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 04/16/2013] [Indexed: 12/11/2022] Open
Abstract
Voltage-gated ion channels are important mediators of physiological functions in the central nervous system. The cyclic activation of these channels influences neurotransmitter release, neuron excitability, gene transcription, and plasticity, providing distinct brain areas with unique physiological and pharmacological response. A growing body of data has implicated ion channels in the susceptibility or pathogenesis of psychiatric diseases. Indeed, population studies support the association of polymorphisms in calcium and potassium channels with the genetic risk for bipolar disorders (BPDs) or schizophrenia. Moreover, point mutations in calcium, sodium, and potassium channel genes have been identified in some childhood developmental disorders. Finally, antibodies against potassium channel complexes occur in a series of autoimmune psychiatric diseases. Here we report recent studies assessing the role of calcium, sodium, and potassium channels in BPD, schizophrenia, and autism spectrum disorders, and briefly summarize promising pharmacological strategies targeted on ion channels for the therapy of mental illness and related genetic tests.
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Affiliation(s)
- Paola Imbrici
- Section of Pharmacology, Department of Pharmacy - Drug Science, University of Bari Bari, Italy
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Genome-wide gene expression in a patient with 15q13.3 homozygous microdeletion syndrome. Eur J Hum Genet 2013; 21:1093-9. [PMID: 23361223 DOI: 10.1038/ejhg.2013.1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 12/07/2012] [Accepted: 01/04/2013] [Indexed: 11/08/2022] Open
Abstract
We identified a novel homozygous 15q13.3 microdeletion in a young boy, with a complex neurodevelopmental disorder characterized by severe cerebral visual impairment with additional signs of congenital stationary night blindness, congenital hypotonia with areflexia, profound intellectual disability, and refractory epilepsy. The mechanisms by which the genes in the deleted region exert their effect are unclear. In this paper, we probed the role of downstream effects of the deletions as a contributing mechanism to the molecular basis of the observed phenotype. We analyzed gene expression of lymphoblastoid cells derived from peripheral blood of the proband and his relatives to ascertain the relative effects of the homozygous and heterozygous deletions. We identified 267 genes with apparent differential expression between the proband with the homozygous deletion and 3 age- and sex-matched typically developing controls. Several of the differentially expressed genes are known to influence neurodevelopment and muscular function, and thus may contribute to the observed cognitive impairment and hypotonia. We further investigated the role of CHRNA7 by measuring TNFα modulation (a potentially important pathway in regulating synaptic plasticity). We found that the cell line with the homozygous deletion lost the ability to inhibit the activation of tumor necrosis factor-α secretion. Our findings suggest downstream genes that may have been altered by the 15q13.3 homozygous deletion, and thus contributed to the severe developmental encephalopathy of the proband. Furthermore, we show that a potentially important pathway in learning and development is affected by the deletion of CHRNA7.
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Hoppman-Chaney N, Wain K, Seger PR, Superneau DW, Hodge JC. Identification of single gene deletions at 15q13.3: further evidence that CHRNA7 causes the 15q13.3 microdeletion syndrome phenotype. Clin Genet 2012; 83:345-51. [PMID: 22775350 DOI: 10.1111/j.1399-0004.2012.01925.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 06/29/2012] [Accepted: 06/29/2012] [Indexed: 11/29/2022]
Abstract
The 15q13.3 microdeletion syndrome (OMIM #612001) is characterized by a wide range of phenotypic features, including intellectual disability, seizures, autism, and psychiatric conditions. This deletion is inherited in approximately 75% of cases and has been found in mildly affected and normal parents, consistent with variable expressivity and incomplete penetrance. The common deletion is approximately 2 Mb and contains several genes; however, the gene(s) responsible for the resulting clinical features have not been clearly defined. Recently, four probands were reported with small deletions including only the CHRNA7 gene. These patients showed a wide range of phenotypic features similar to those associated with the larger 15q13.3 microdeletion. To further correlate genotype and phenotype, we queried our database of >15,000 patients tested in the Mayo Clinic Cytogenetics Laboratory from 2008 to 2011 and identified 19 individuals (10 probands and 9 family members) with isolated heterozygous CHRNA7 gene deletions. All but two infants displayed multiple features consistent with 15q13.3 microdeletion syndrome. We also identified the first de novo deletion confined to CHRNA7 as well as the second known case with homozygous deletion of CHRNA7 only. These results provide further evidence implicating CHRNA7 as the gene responsible for the clinical findings associated with 15q13.3 microdeletion.
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Affiliation(s)
- N Hoppman-Chaney
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA.
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Abstract
Fanconi anemia (FA) is a rare bone marrow failure disorder with defective DNA interstrand crosslink repair. Still, there are FA patients without mutations in any of the 15 genes individually underlying the disease. A candidate protein for those patients, FA nuclease 1 (FAN1), whose gene is located at chromosome 15q13.3, is recruited to stalled replication forks by binding to monoubiquitinated FANCD2 and is required for interstrand crosslink repair, suggesting that mutation of FAN1 may cause FA. Here we studied clinical, cellular, and genetic features in 4 patients carrying a homozygous 15q13.3 micro-deletion, including FAN1 and 6 additional genes. Biallelic deletion of the entire FAN1 gene was confirmed by failure of 3'- and 5'-PCR amplification. Western blot analysis failed to show FAN1 protein in the patients' cell lines. Chromosome fragility was normal in all 4 FAN1-deficient patients, although their cells showed mild sensitivity to mitomycin C in terms of cell survival and G(2) phase arrest, dissimilar in degree to FA cells. Clinically, there were no symptoms pointing the way to FA. Our results suggest that FAN1 has a minor role in interstrand crosslink repair compared with true FA genes and exclude FAN1 as a novel FA gene.
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