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Kleinendorst L, Abawi O, Vos N, van der Valk ES, Maas SM, Morgan AT, Hildebrand MS, Da Silva JD, Florijn RJ, Lauffer P, Visser JA, van Rossum EFC, van den Akker ELT, van Haelst MM. GNB1 and obesity: Evidence for a correlation between haploinsufficiency and syndromic obesity. Clin Obes 2024; 14:e12661. [PMID: 38596856 DOI: 10.1111/cob.12661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 03/26/2024] [Indexed: 04/11/2024]
Abstract
Most patients with GNB1 encephalopathy have developmental delay and/or intellectual disability, brain anomalies and seizures. Recently, two cases with GNB1 encephalopathy caused by haploinsufficiency have been reported that also show a Prader-Willi-like phenotype of childhood hypotonia and severe obesity. Here we present three new cases from our expert centre for genetic obesity in which GNB1 truncating and splice variants, probably leading to haploinsufficiency, were identified. They all have obesity, hyperphagia and intellectual deficit. The clinical cases and their weight courses are presented, together with a review of all 68 published cases with GNB1 encephalopathy. Information on weight was not mentioned in most of these articles, so we contacted authors for additional clinical information on weight status and hyperphagia. Of the 42 patients whose weight status we could determine, obesity was present in 8 patients (19%). Obesity is significantly over-represented in the group with truncating and splicing variants. In this group, we see an obesity prevalence of 75%. Since GNB1 has been linked to several key genes in the hypothalamic leptin-melanocortin pathway, which regulates satiety and energy expenditure, our data support the potential association between GNB1 haploinsufficiency and genetic obesity. We also suggest GNB1 is a candidate gene for the known obesity phenotype of the 1p36 microdeletion syndrome given this chromosomal region includes the GNB1 gene. Knowledge of an additional obesity phenotype is important for prognosis, early interventions against obesity and awareness when prescribing weight-inducing medication.
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Affiliation(s)
- Lotte Kleinendorst
- Department of Human Genetics, Amsterdam Reproduction & Development Research Institute, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
- Emma Center for Personalized Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Ozair Abawi
- Department of Pediatrics, Division of Endocrinology, Erasmus MC-Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, the Netherlands
- Obesity Center CGG, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - Niels Vos
- Department of Human Genetics, Amsterdam Reproduction & Development Research Institute, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Eline S van der Valk
- Obesity Center CGG, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
- Department of Internal Medicine, Division of Endocrinology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - Saskia M Maas
- Department of Human Genetics, Amsterdam Reproduction & Development Research Institute, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | | | - Michael S Hildebrand
- Murdoch Children's Research Institute, Melbourne, Australia
- Department of Medicine, Austin Health, University of Melbourne, Melbourne, Australia
| | - Jorge D Da Silva
- Centro de Genética Médica Doutor Jacinto Magalhães, Centro Hospitalar Universitário do Porto & Unit for Multidisciplinary Research in Biomedicine, Abel Salazar Biomedical Sciences Institute, Porto University, Porto, Portugal
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Ralph J Florijn
- Department of Human Genetics, Amsterdam Reproduction & Development Research Institute, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Peter Lauffer
- Department of Human Genetics, Amsterdam Reproduction & Development Research Institute, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Jenny A Visser
- Obesity Center CGG, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
- Department of Internal Medicine, Division of Endocrinology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - Elisabeth F C van Rossum
- Obesity Center CGG, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
- Department of Internal Medicine, Division of Endocrinology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - Erica L T van den Akker
- Department of Pediatrics, Division of Endocrinology, Erasmus MC-Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, the Netherlands
- Obesity Center CGG, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - Mieke M van Haelst
- Department of Human Genetics, Amsterdam Reproduction & Development Research Institute, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
- Emma Center for Personalized Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
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Nasvytis M, Čiauškaitė J, Jurkevičienė G. GNB1 Encephalopathy: Clinical Case Report and Literature Review. MEDICINA (KAUNAS, LITHUANIA) 2024; 60:589. [PMID: 38674235 PMCID: PMC11051738 DOI: 10.3390/medicina60040589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 03/13/2024] [Accepted: 03/31/2024] [Indexed: 04/28/2024]
Abstract
GNB1 encephalopathy is a rare genetic disease caused by pathogenic variants in the G Protein Subunit Beta 1 (GNB1) gene, with only around 68 cases documented worldwide. Although most cases had been caused by de novo germline mutations, in this case, the pathogenic variant was inherited from patient's mother, indicating an autosomal dominant inheritance pattern. The patient presented at 25 years of age with mild developmental delay and cognitive impairment, prominent generalized dystonia, and horizontal nystagmus which are all characterizing symptoms of GNB1 encephalopathy. Electroencephalography (EEG) showed no epileptiform patterns, and magnetic resonance imaging (MRI) revealed hypointensities in globus pallidus and dentate nucleus areas. The main theory for GNB1 encephalopathy pathogenesis is neuronal hyperexcitability caused by impaired ion channel regulation. Due to low specificity of symptoms, diagnosis relies on genetic testing. As there are no standardized GNB1 encephalopathy treatment guidelines, evaluation of different treatment options is based on anecdotal cases. Reviewing different treatment options, deep brain stimulation and intrathecal baclofen pump, as well as some other medications still in preclinical trials, seem to be the most promising.
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Affiliation(s)
| | - Julija Čiauškaitė
- Department of Neurology, Medical Academy, Lithuanian University of Health Sciences, 44307 Kaunas, Lithuania; (J.Č.); (G.J.)
| | - Giedrė Jurkevičienė
- Department of Neurology, Medical Academy, Lithuanian University of Health Sciences, 44307 Kaunas, Lithuania; (J.Č.); (G.J.)
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Conti GM, Cancellieri F, Quinodoz M, Kaminska K, Vaclavik V, Rivolta C, Tran HV. GNB1-Related Rod-Cone Dystrophy: A Case Report. Case Rep Ophthalmol 2024; 15:230-237. [PMID: 38500542 PMCID: PMC10948171 DOI: 10.1159/000537997] [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: 09/26/2023] [Accepted: 02/19/2024] [Indexed: 03/20/2024] Open
Abstract
Introduction The GNB1 (guanine nucleotide-binding protein, β1) gene encodes for the ubiquitous β1 subunit of heterotrimeric G proteins, which are associated with G-protein-coupled receptors (GPCRs). GNB1 mutations cause a neurodevelopmental disorder characterized by a broad clinical spectrum. A novel variant has recently been confirmed in a case of rod-cone dystrophy. Case Presentation We describe the second confirmed case of a classical rod-cone dystrophy associated with a mutation located in exon 6 of GNB1 [NM_002074.5:c.217G>C, p.(Ala73Pro)] in a 56-year-old patient also presenting mild intellectual disability, attention deficit/hyperactivity disorder, and truncal obesity. Conclusion This paper confirms the role of GNB1 in the pathogenesis of a classic rod-cone dystrophy and highlights the importance of including this gene in the genetic analysis panel for inherited retinal diseases.
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Affiliation(s)
- Giovanni Marco Conti
- Genetic Ophthalmic Department, Hôpital Ophtalmique Jules-Gonin, University of Lausanne and Faculty of Life Sciences, Lausanne, Switzerland
- Institut D’Ophtalmologie de Vevey (INOV), Vevey, Switzerland
| | - Francesca Cancellieri
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland
- Department of Ophthalmology, University of Basel, Basel, Switzerland
| | - Mathieu Quinodoz
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland
- Department of Ophthalmology, University of Basel, Basel, Switzerland
- Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - Karolina Kaminska
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland
- Department of Ophthalmology, University of Basel, Basel, Switzerland
| | - Veronika Vaclavik
- Genetic Ophthalmic Department, Hôpital Ophtalmique Jules-Gonin, University of Lausanne and Faculty of Life Sciences, Lausanne, Switzerland
| | - Carlo Rivolta
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland
- Department of Ophthalmology, University of Basel, Basel, Switzerland
- Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - Hoai Viet Tran
- Genetic Ophthalmic Department, Hôpital Ophtalmique Jules-Gonin, University of Lausanne and Faculty of Life Sciences, Lausanne, Switzerland
- Institut D’Ophtalmologie de Vevey (INOV), Vevey, Switzerland
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, London, UK
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Yang H, Huang J, Zheng H, Zhang Y, Zhang Y, Liu W, Wu J, Chen X, Lin J, Ni Y, Nie X. Deletion in 1p36.33-p36.32 is associated with pancytopenia: a case report. BMC Med Genomics 2023; 16:282. [PMID: 37946214 PMCID: PMC10634020 DOI: 10.1186/s12920-023-01723-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 10/31/2023] [Indexed: 11/12/2023] Open
Abstract
BACKGROUND 1P36 deletion syndrome is recognized as the most common terminal microdeletion syndrome in humans, characterized by early developmental delay and consequent intellectual disability, seizure disorder, and distinctive facial features. Variable deletion locations may attributed to phenotypic variability. However, the abnormal phenotypes of hematology are rarely reported in 1P36 deletion syndrome patients. CASE PRESENTATION We present a case of postnatal intellectual disability accompanied by pancytopenia. Copy number variation analysis revealed a pathogenic deletion in 1p36.331p36.32 with a deletion size of 2.21 Mb. Following successful treatment with glucocorticoids, the patient was diagnosed with immuno-related hemocytopenia (IRH). DISCUSSION The patient experienced IRH, an uncommon characteristic of 1p36 deletion syndrome. The deletion fragment of 1p36.33-p36.32, particularly the loss of GNB1 gene, has been associated with the development of pancytopenia. Genotype-phenotype correlations are valuable in identifying the genes responsible for various clinical characteristics of the syndrome by associating phenotypic variation with specific genes located within the chromosome deletion region. Genome sequencing is recommended in cases where clinical manifestations indicate the presence of a genetic disorder but pose diagnostic challenges.
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Affiliation(s)
- Huanhuan Yang
- Fuzong Clinical Medical College of Fujian Medical University, Fuzhou, China
- Department of Pediatrics, The 900th Hospital of Joint Logistic Support Force, PLA, Fuzhou, China
| | - Jun Huang
- Fuzong Clinical Medical College of Fujian Medical University, Fuzhou, China
- Department of Pediatrics, The 900th Hospital of Joint Logistic Support Force, PLA, Fuzhou, China
| | - Hao Zheng
- Department of Pediatrics, Fujian Union Hospital, Fuzhou, China
| | - Yunfan Zhang
- Fuzong Clinical Medical College of Fujian Medical University, Fuzhou, China
- Department of Pediatrics, The 900th Hospital of Joint Logistic Support Force, PLA, Fuzhou, China
| | - Yuanzhen Zhang
- Department of Pediatrics, The 900th Hospital of Joint Logistic Support Force, PLA, Fuzhou, China
- Department of Pediatrics, Affiliated Dongfang Hospital, Xiamen University, Fuzhou, China
| | - Wei Liu
- Department of Pediatrics, The 900th Hospital of Joint Logistic Support Force, PLA, Fuzhou, China
| | - Jinrong Wu
- Department of Pediatrics, The 900th Hospital of Joint Logistic Support Force, PLA, Fuzhou, China
| | - Xiaobin Chen
- Department of Pediatrics, The 900th Hospital of Joint Logistic Support Force, PLA, Fuzhou, China
| | - Jinfeng Lin
- Department of Pediatrics, The 900th Hospital of Joint Logistic Support Force, PLA, Fuzhou, China
| | - Yanna Ni
- Department of Pediatrics, The 900th Hospital of Joint Logistic Support Force, PLA, Fuzhou, China
| | - Xiaojing Nie
- Fuzong Clinical Medical College of Fujian Medical University, Fuzhou, China.
- Department of Pediatrics, The 900th Hospital of Joint Logistic Support Force, PLA, Fuzhou, China.
- Department of Pediatrics, Affiliated Dongfang Hospital, Xiamen University, Fuzhou, China.
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Ramírez CG, Azaña Defez JM, Clemente SP, Sanz PL, Córdoba SM. Comment on "Cutaneous mastocytosis in a child with a de novo GNB1 mutation". Pediatr Dermatol 2023; 40:1164-1165. [PMID: 37970691 DOI: 10.1111/pde.15279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 01/27/2023] [Indexed: 11/17/2023]
Affiliation(s)
| | | | - Sara Plata Clemente
- Department of Dermatology, University General Hospital of Albacete, Albacete, Spain
| | - Pablo López Sanz
- Department of Dermatology, University General Hospital of Albacete, Albacete, Spain
| | - Silvia Manso Córdoba
- Department of Dermatology, University General Hospital of Albacete, Albacete, Spain
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Springer MS, Emerling CA, Gatesy J. Three Blind Moles: Molecular Evolutionary Insights on the Tempo and Mode of Convergent Eye Degeneration in Notoryctes typhlops (Southern Marsupial Mole) and Two Chrysochlorids (Golden Moles). Genes (Basel) 2023; 14:2018. [PMID: 38002961 PMCID: PMC10671557 DOI: 10.3390/genes14112018] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 10/20/2023] [Accepted: 10/25/2023] [Indexed: 11/26/2023] Open
Abstract
Golden moles (Chrysochloridae) and marsupial moles (Notoryctidae) are textbook examples of convergent evolution. Both taxa are highly adapted to subterranean lifestyles and have powerful limbs for digging through the soil/sand, ears that are adapted for low-frequency hearing, vestigial eyes that are covered by skin and fur, and the absence of optic nerve connections between the eyes and the brain. The eyes of marsupial moles also lack a lens as well as retinal rods and cones. Two hypotheses have been proposed to account for the greater degeneracy of the eyes of marsupial moles than golden moles. First, marsupial moles may have had more time to adapt to their underground habitat than other moles. Second, the eyes of marsupial moles may have been rapidly and recently vestigialized to (1) reduce the injurious effects of sand getting into the eyes and (2) accommodate the enlargement of lacrimal glands that keep the nasal cavity moist and prevent the entry of sand into the nasal passages during burrowing. Here, we employ molecular evolutionary methods on DNA sequences for 38 eye genes, most of which are eye-specific, to investigate the timing of relaxed selection (=neutral evolution) for different groups of eye-specific genes that serve as proxies for distinct functional components of the eye (rod phototransduction, cone phototransduction, lens/cornea). Our taxon sampling included 12 afrothere species, of which two are golden moles (Amblysomus hottentotus, Chrysochloris asiatica), and 28 marsupial species including two individuals of the southern marsupial mole (Notoryctes typhlops). Most of the sequences were mined from databases, but we also provide new genome data for A. hottentotus and one of the two N. typhlops individuals. Even though the eyes of golden moles are less degenerate than the eyes of marsupial moles, there are more inactivating mutations (e.g., frameshift indels, premature stop codons) in their cone phototransduction and lens/cornea genes than in orthologous genes of the marsupial mole. We estimate that cone phototransduction recovery genes were inactivated first in each group, followed by lens/cornea genes and then cone phototransduction activation genes. All three groups of genes were inactivated earlier in golden moles than in marsupial moles. For the latter, we estimate that lens/cornea genes were inactivated ~17.8 million years ago (MYA) when stem notoryctids were burrowing in the soft soils of Australian rainforests. Selection on phototransduction activation genes was relaxed much later (5.38 MYA), during the early stages of Australia's aridification that produced coastal sand plains and eventually sand dunes. Unlike cone phototransduction activation genes, rod phototransduction activation genes are intact in both golden moles and one of the two individuals of N. typhlops. A second marsupial mole individual has just a single inactivating mutation in one of the rod phototransduction activation genes (PDE6B). One explanation for this result is that some rod phototransduction activation genes are pleiotropic and are expressed in extraocular tissues, possibly in conjunction with sperm thermotaxis.
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Affiliation(s)
- Mark S. Springer
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA 92521, USA
| | | | - John Gatesy
- Division of Vertebrate Zoology, American Museum of Natural History, New York, NY 10024, USA;
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Choi HB, Na Y, Lee J, Lee J, Jang JH, Kim JW, Kwon JY. Case report: Suspecting guanine nucleotide-binding protein beta 1 mutation in dyskinetic cerebral palsy is important. Front Pediatr 2023; 11:1204360. [PMID: 37900673 PMCID: PMC10611516 DOI: 10.3389/fped.2023.1204360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 09/25/2023] [Indexed: 10/31/2023] Open
Abstract
Herein, we describe the case of a 43-month-old girl who presented with clinical manifestations of dyskinetic cerebral palsy (CP), classified as the Gross Motor Function Classification System (GMFCS) V. The patient had no family history of neurological or perinatal disorders. Despite early rehabilitation, serial assessments using the Gross Motor Function Measure (GMFM) showed no significant improvements in gross motor function. Brain magnetic resonance imaging showed nonspecific findings that could not account for developmental delay or dystonia. Whole-genome sequencing identified a heterozygous NM_002074.5(GNB1):c.239T>C (p.Ile80Thr) mutation in guanine nucleotide-binding protein beta 1 (GNB1) gene. Considering this case and previous studies, genetic testing for the etiology of dyskinetic CP is recommended for children without relevant or with nonspecific brain lesions.
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Affiliation(s)
- Han-Byeol Choi
- Department of Physical and Rehabilitation Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Yoonju Na
- Department of Physical and Rehabilitation Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Jiwon Lee
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Jeehun Lee
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Ja-Hyun Jang
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Jong-Won Kim
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
- Department of Health Science and Technology, Samsung Advanced Institute for Health Science and Technology, Sungkyunkwan University, Seoul, Republic of Korea
| | - Jeong-Yi Kwon
- Department of Physical and Rehabilitation Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
- Department of Health Science and Technology, Samsung Advanced Institute for Health Science and Technology, Sungkyunkwan University, Seoul, Republic of Korea
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Tsuji M, Ikeda A, Tsuyusaki Y, Iai M, Kurosawa K, Kosaki K, Goto T. Atypical clinical course in two patients with GNB1 variants who developed acute encephalopathy. Brain Dev 2023; 45:462-466. [PMID: 37453880 DOI: 10.1016/j.braindev.2023.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 06/15/2023] [Accepted: 06/18/2023] [Indexed: 07/18/2023]
Abstract
INTRODUCTION Variants in the GNB1 gene, which encodes the β1 subunit of a trimeric G protein, can cause moderate to severe psychomotor retardation. Acute encephalopathies have also been observed in patients with central nervous system abnormalities; however, severe neurological sequelae have not previously been reported. CASE PRESENTATIONS Patient 1 was a Japanese female with a de novo GNB1 variant (c.284 T > C). At 8 months old she contracted influenza A and developed generalized convulsions. In the acute phase, brain magnetic resonance imaging (MRI) findings indicated acute encephalopathy; diffuse cerebral atrophy was present 1 month later. Although multidisciplinary treatment was administered, she had severe neurological sequelae including spastic tetraplegia, severe intellectual disabilities, and refractory epilepsy. Patient 2 was a Japanese male with a de novo GNB1 variant (c.239 T > C). He experienced an unexplained respiratory arrest aged 17 years; refractory convulsions developed. Brain MRI at 1 month showed bilateral basal ganglia high intensities; at 3 months, diffuse cerebral cortex and white matter atrophy was observed. Despite multidisciplinary treatment, he developed severe spastic tetraplegia and mental regression. DISCUSSION We report two patients with GNB1 variants who had acute lesions on brain MRI and unexpected disease courses. In such patients with acute neurological deterioration, multidisciplinary treatment is required; patients should also be carefully observed for progression to acute encephalopathy.
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Affiliation(s)
- Megumi Tsuji
- Department of Neurology, Kanagawa Children's Medical Center, 2-138-4 Mutsukawa, Minami-ku, Yokohama 232-8555, Japan; Institution for Children with Profound Multiple Disabilities, Kanagawa Children's Medical Center, 2-138-4 Mutsukawa, Minami-ku, Yokohama 232-8555, Japan.
| | - Azusa Ikeda
- Department of Neurology, Kanagawa Children's Medical Center, 2-138-4 Mutsukawa, Minami-ku, Yokohama 232-8555, Japan.
| | - Yu Tsuyusaki
- Department of Neurology, Kanagawa Children's Medical Center, 2-138-4 Mutsukawa, Minami-ku, Yokohama 232-8555, Japan.
| | - Mizue Iai
- Department of Neurology, Kanagawa Children's Medical Center, 2-138-4 Mutsukawa, Minami-ku, Yokohama 232-8555, Japan; Institution for Children with Profound Multiple Disabilities, Kanagawa Children's Medical Center, 2-138-4 Mutsukawa, Minami-ku, Yokohama 232-8555, Japan.
| | - Kenji Kurosawa
- Department of Genetics, Kanagawa Children's Medical Center, 2-138-4 Mutsukawa, Minami-ku, Yokohama 232-8555, Japan.
| | - Kenjiro Kosaki
- Center for Medical Genetics, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
| | - Tomohide Goto
- Department of Neurology, Kanagawa Children's Medical Center, 2-138-4 Mutsukawa, Minami-ku, Yokohama 232-8555, Japan.
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Jiao J, Wang Y, Hou Y, Gao C, Shi H, Tian S. Clinical characterization of familial 1p36.3 microduplication. Neurogenetics 2023; 24:201-208. [PMID: 37289317 PMCID: PMC10319691 DOI: 10.1007/s10048-023-00722-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 05/25/2023] [Indexed: 06/09/2023]
Abstract
Unlike the 1p36 microdeletion syndrome, which has been extensively described, 1p36.3 microduplications have rarely been reported. We report the two siblings of familial 1p36.3 microduplication, presenting with a severe global developmental delay, epilepsy, and a few dysmorphic features. They were referred to moderate-to-severe developmental delay (DD) and intellectual disability (ID). Both were considered eyelid myoclonus with absence of epilepsy (Jeavons syndrome). The EEG is characterized by widespread 2.5-3.5 Hz spikes and spike slow complex wave, eye closure sensitivity, and photosensitivity. The children has same dysmorphic features, including mild bitemporal narrowing and sloping forehead, sparse eyebrows, hypertelorism, ptosis, strabismus, infraorbital creases, wide nasal bridge with bulbous nasal tip, dystaxia, hallux valgus, and flat feet. Family exome sequencing revealed a maternally inherited 3.2-Mb microduplication of chromosomal band 1p36.3p36.2. However, DNA purified from blood samples of either parent did not find evidence for a microduplication of 1p36 in somatic tissue, indicating that such a mutation might be carried in the germline of the parents as gonadal mosaicism. No other family members of the affected siblings' parents were reported to be affected by the symptoms found.
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Affiliation(s)
- Junping Jiao
- Department of Neurology, The First Hospital of Hebei Medical University, Shijiangzhuang City, Hebei Province, China
| | - Yuping Wang
- Xuanwu Hospital Capital Medical University, Beijing, China
| | - Yue Hou
- Xuanwu Hospital Capital Medical University, Beijing, China
| | - Chao Gao
- Department of Neurology, The First Hospital of Hebei Medical University, Shijiangzhuang City, Hebei Province, China
| | - Huimin Shi
- Department of Neurology, The First Hospital of Hebei Medical University, Shijiangzhuang City, Hebei Province, China
| | - Shujuan Tian
- Department of Neurology, The First Hospital of Hebei Medical University, Shijiangzhuang City, Hebei Province, China.
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Colombo S, Reddy HP, Petri S, Williams DJ, Shalomov B, Dhindsa RS, Gelfman S, Krizay D, Bera AK, Yang M, Peng Y, Makinson CD, Boland MJ, Frankel WN, Goldstein DB, Dascal N. Epilepsy in a mouse model of GNB1 encephalopathy arises from altered potassium (GIRK) channel signaling and is alleviated by a GIRK inhibitor. Front Cell Neurosci 2023; 17:1175895. [PMID: 37275776 PMCID: PMC10232839 DOI: 10.3389/fncel.2023.1175895] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 04/12/2023] [Indexed: 06/07/2023] Open
Abstract
De novo mutations in GNB1, encoding the Gβ1 subunit of G proteins, cause a neurodevelopmental disorder with global developmental delay and epilepsy, GNB1 encephalopathy. Here, we show that mice carrying a pathogenic mutation, K78R, recapitulate aspects of the disorder, including developmental delay and generalized seizures. Cultured mutant cortical neurons also display aberrant bursting activity on multi-electrode arrays. Strikingly, the antiepileptic drug ethosuximide (ETX) restores normal neuronal network behavior in vitro and suppresses spike-and-wave discharges (SWD) in vivo. ETX is a known blocker of T-type voltage-gated Ca2+ channels and G protein-coupled potassium (GIRK) channels. Accordingly, we present evidence that K78R results in a gain-of-function (GoF) effect by increasing the activation of GIRK channels in cultured neurons and a heterologous model (Xenopus oocytes)-an effect we show can be potently inhibited by ETX. This work implicates a GoF mechanism for GIRK channels in epilepsy, identifies a new mechanism of action for ETX in preventing seizures, and establishes this mouse model as a pre-clinical tool for translational research with predicative value for GNB1 encephalopathy.
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Affiliation(s)
- Sophie Colombo
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
| | - Haritha P. Reddy
- Department of Physiology and Pharmacology, School of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, India
| | - Sabrina Petri
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
| | - Damian J. Williams
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
| | - Boris Shalomov
- Department of Physiology and Pharmacology, School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ryan S. Dhindsa
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
| | - Sahar Gelfman
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
| | - Daniel Krizay
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
| | - Amal K. Bera
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, India
| | - Mu Yang
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
- Mouse NeuroBehavior Core Facility, Columbia University Irving Medical Center, New York, NY, United States
| | - Yueqing Peng
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, United States
| | - Christopher D. Makinson
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, United States
- Department of Neuroscience, Columbia University, New York, NY, United States
| | - Michael J. Boland
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, United States
| | - Wayne N. Frankel
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY, United States
| | - David B. Goldstein
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY, United States
| | - Nathan Dascal
- Department of Physiology and Pharmacology, School of Medicine, Tel Aviv University, Tel Aviv, Israel
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11
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Khan SM, Martin RD, Bayne A, Pétrin D, Bourque K, Jones-Tabah J, Bouazza C, Blaney J, Lau J, Martins-Cannavino K, Gora S, Zhang A, MacKinnon S, Trieu P, Clarke PBS, Trempe JF, Tanny JC, Hébert TE. Gβγ subunits colocalize with RNA polymerase II and regulate transcription in cardiac fibroblasts. J Biol Chem 2023; 299:103064. [PMID: 36841480 PMCID: PMC10060754 DOI: 10.1016/j.jbc.2023.103064] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 02/08/2023] [Accepted: 02/09/2023] [Indexed: 02/26/2023] Open
Abstract
Gβγ subunits mediate many different signaling processes in various compartments of the cell, including the nucleus. To gain insight into the functions of nuclear Gβγ signaling, we investigated the functional role of Gβγ signaling in the regulation of GPCR-mediated gene expression in primary rat neonatal cardiac fibroblasts. We identified a novel, negative, regulatory role for the Gβ1γ dimer in the fibrotic response. Depletion of Gβ1 led to derepression of the fibrotic response at the mRNA and protein levels under basal conditions and an enhanced fibrotic response after sustained stimulation of the angiotensin II type I receptor. Our genome-wide chromatin immunoprecipitation experiments revealed that Gβ1 colocalized and interacted with RNA polymerase II on fibrotic genes in an angiotensin II-dependent manner. Additionally, blocking transcription with inhibitors of Cdk9 prevented association of Gβγ with transcription complexes. Together, our findings suggest that Gβ1γ is a novel transcriptional regulator of the fibrotic response that may act to restrict fibrosis to conditions of sustained fibrotic signaling. Our work expands the role for Gβγ signaling in cardiac fibrosis and may have broad implications for the role of nuclear Gβγ signaling in other cell types.
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Affiliation(s)
- Shahriar M Khan
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Ryan D Martin
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Andrew Bayne
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada; Centre de Recherche en Biologie Structurale, McGill University, Montréal, Québec, Canada
| | - Darlaine Pétrin
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Kyla Bourque
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Jace Jones-Tabah
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Celia Bouazza
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Jacob Blaney
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Jenny Lau
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | | | - Sarah Gora
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Andy Zhang
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Sarah MacKinnon
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Phan Trieu
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Paul B S Clarke
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Jean-François Trempe
- Centre de Recherche en Biologie Structurale, McGill University, Montréal, Québec, Canada
| | - Jason C Tanny
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada.
| | - Terence E Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada.
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12
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Reyes NGD, Di Luca DG, McNiven V, Lang AE. Dystonia with myoclonus and vertical supranuclear gaze palsy associated with a rare GNB1 variant. Parkinsonism Relat Disord 2023; 106:105239. [PMID: 36521323 DOI: 10.1016/j.parkreldis.2022.105239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/29/2022] [Accepted: 12/05/2022] [Indexed: 12/14/2022]
Abstract
GNB1 encephalopathy (OMIM: 616973), caused by pathogenic variants in the GNB1 gene, is a rare neurodevelopmental syndrome characterized by global developmental delay (GDD) variably co-occurring with movement disorders. For the latter, dystonia, although the most frequent, remains uncommon. Other phenomenologies including myoclonus, tics, chorea, and ataxia, as well as oculomotor abnormalities are rare [1]. Most pathogenic variants in GNBI occur in exons 6 and 7, which are considered to be mutational hotspots [2]. Here, we report a case of GNB1 encephalopathy arising from a de novo mutation in a gene region with few reported pathogenic variants (i.e., exon 11) presenting with a unique phenotype consisting of dystonia with myoclonus and vertical supranuclear gaze palsy.
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Affiliation(s)
- Nikolai Gil D Reyes
- Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, Toronto, Ontario, Canada.
| | - Daniel G Di Luca
- Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, Toronto, Ontario, Canada; Institute of Health Policy, Management and Evaluation, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
| | - Vanda McNiven
- Division of Clinical and Metabolic Genetics, Department of Pediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada; Fred A Litwin Family Centre in Genetic Medicine, University Health Network and Mount Sinai Hospital, Toronto, ON, M5T 3L9, Canada.
| | - Anthony E Lang
- Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, Toronto, Ontario, Canada.
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13
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Rojnueangnit K, Anthanont P, Khetkham T, Puttamanee S, Ittiwut C. Genetic diagnosis for adult patients at a genetic clinic. Cold Spring Harb Mol Case Stud 2022; 8:a006235. [PMID: 36265913 PMCID: PMC9808555 DOI: 10.1101/mcs.a006235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 10/04/2022] [Indexed: 01/31/2023] Open
Abstract
Clinical utility of genetic testing has rapidly increased in the past decade to identify the definitive diagnosis, etiology, and specific management. The majority of patients receiving testing are children. There are several barriers for genetic tests in adult patients; barriers may arise from either patients or clinicians. Our study aims to realize the detection rate and the benefits of genetic tests in adults. We conducted a prospective study of 10 adult patients who were referred to a genetic clinic. Exome sequencing (ES) was pursued in all cases, and chromosomal microarray (CMA) was performed for six cases. Our result is impressive; six cases (60%) received likely pathogenic and pathogenic variants. Four definitive diagnosis cases had known pathogenic variants in KCNJ2, TGFBR1, SCN1A, and FBN1, whereas another two cases revealed novel likely pathogenic and pathogenic variants in GNB1 and DNAH9. Our study demonstrates the success in genetic diagnosis in adult patients: four cases with definitive, two cases with possible, and one case with partial diagnosis. The advantage of diagnosis is beyond obtaining the diagnosis itself, but also relieving any doubt for the patient regarding any previous questionable diagnosis, guide for management, and recurrence risk in their children or family members. Therefore, this supports the value of genetic testing in adult patients.
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Affiliation(s)
- Kitiwan Rojnueangnit
- Department of Pediatrics, Faculty of Medicine, Thammasat University, Pathumthani, 12120 Thailand
| | - Pimjai Anthanont
- Department of Medicine, Faculty of Medicine, Thammasat University, Pathumthani, 12120 Thailand
| | - Thanitchet Khetkham
- Division of Forensic Medicine, Thammasat University Hospital, 12120 Thailand
| | - Sukita Puttamanee
- Faculty of Medicine, Thammasat University, Pathumthani, 12120 Thailand
| | - Chupong Ittiwut
- Center of Excellence for Medical Genomics, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330 Thailand
- Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, 10330 Thailand
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14
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GNB3 c.825C>T (rs5443) Polymorphism and Risk of Acute Cardiovascular Events after Renal Allograft Transplant. Int J Mol Sci 2022; 23:ijms23179783. [PMID: 36077181 PMCID: PMC9456448 DOI: 10.3390/ijms23179783] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 08/22/2022] [Accepted: 08/24/2022] [Indexed: 11/17/2022] Open
Abstract
The c.825C>T single-nucleotide polymorphism (rs5443) of the guanine nucleotide-binding protein subunit β3 (GNB3) results in increased intracellular signal transduction via G-proteins. The present study investigated the effect of the GNB3 c.825C>T polymorphism on cardiovascular events among renal allograft recipients posttransplant. Our retrospective study involved 436 renal allograft recipients who were followed up for up to 8 years after transplant. The GNB3 c.825C>T polymorphism was detected with restriction fragment length polymorphism (RFLP) polymerase chain reaction (PCR). The GNB3 TT genotype was detected in 43 (10%) of 436 recipients. Death due to an acute cardiovascular event occurred more frequently among recipients with the TT genotype (4 [9%]) than among those with the CC/CT genotypes (7 [2%]; p = 0.003). The rates of myocardial infarction (MI)−free survival (p = 0.003) and acute peripheral artery occlusive disease (PAOD)−free survival (p = 0.004) were significantly lower among T-homozygous patients. A multivariate analysis showed that homozygous GNB3 c.825C>T polymorphism exerted only a mild effect for the occurrence of myocardial infarction (relative risk, 2.2; p = 0.065) or acute PAOD (relative risk, 2.4; p = 0.05) after renal transplant. Our results suggest that the homozygous GNB3 T allele exerts noticeable effects on the risk of MI and acute PAOD only in the presence of additional nonheritable risk factors.
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15
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Galosi S, Pollini L, Novelli M, Bernardi K, Di Rocco M, Martinelli S, Leuzzi V. Motor, epileptic, and developmental phenotypes in genetic disorders affecting G protein coupled receptors-cAMP signaling. Front Neurol 2022; 13:886751. [PMID: 36003298 PMCID: PMC9393484 DOI: 10.3389/fneur.2022.886751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 07/13/2022] [Indexed: 11/13/2022] Open
Abstract
Over the last years, a constantly increasing number of genetic diseases associated with epilepsy and movement disorders have been recognized. An emerging group of conditions in this field is represented by genetic disorders affecting G-protein-coupled receptors (GPCRs)–cAMP signaling. This group of postsynaptic disorders includes genes encoding for proteins highly expressed in the central nervous system and involved in GPCR signal transduction and cAMP production (e.g., GNAO1, GNB1, ADCY5, GNAL, PDE2A, PDE10A, and HPCA genes). While the clinical phenotype associated with ADCY5 and GNAL is characterized by movement disorder in the absence of epilepsy, GNAO1, GNB1, PDE2A, PDE10A, and HPCA have a broader clinical phenotype, encompassing movement disorder, epilepsy, and neurodevelopmental disorders. We aimed to provide a comprehensive phenotypical characterization of genetic disorders affecting the cAMP signaling pathway, presenting with both movement disorders and epilepsy. Thus, we reviewed clinical features and genetic data of 203 patients from the literature with GNAO1, GNB1, PDE2A, PDE10A, and HPCA deficiencies. Furthermore, we delineated genotype–phenotype correlation in GNAO1 and GNB1 deficiency. This group of disorders presents with a highly recognizable clinical phenotype combining distinctive motor, epileptic, and neurodevelopmental features. A severe hyperkinetic movement disorder with potential life-threatening exacerbations and high susceptibility to a wide range of triggers is the clinical signature of the whole group of disorders. The existence of a distinctive clinical phenotype prompting diagnostic suspicion and early detection has relevant implications for clinical and therapeutic management. Studies are ongoing to clarify the pathophysiology of these rare postsynaptic disorders and start to design disease-specific treatments.
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Affiliation(s)
- Serena Galosi
- Department Human Neuroscience, Sapienza University, Rome, Italy
- *Correspondence: Serena Galosi
| | - Luca Pollini
- Department Human Neuroscience, Sapienza University, Rome, Italy
| | - Maria Novelli
- Department Human Neuroscience, Sapienza University, Rome, Italy
| | | | - Martina Di Rocco
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Simone Martinelli
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Vincenzo Leuzzi
- Department Human Neuroscience, Sapienza University, Rome, Italy
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16
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The Genetic Diagnosis of Ultrarare DEEs: An Ongoing Challenge. Genes (Basel) 2022; 13:genes13030500. [PMID: 35328054 PMCID: PMC8953579 DOI: 10.3390/genes13030500] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/04/2022] [Accepted: 03/10/2022] [Indexed: 02/06/2023] Open
Abstract
Epileptic encephalopathies (EEs) and developmental and epileptic encephalopathies (DEEs) are a group of severe early-onset neurodevelopmental disorders (NDDs). In recent years, next-generation equencing (NGS) technologies enabled the discovery of numerous genes involved in these conditions. However, more than 50% of patients remained undiagnosed. A major obstacle lies in the high degree of genetic heterogeneity and the wide phenotypic variability that has characterized these disorders. Interpreting a large amount of NGS data is also a crucial challenge. This study describes a dynamic diagnostic procedure used to investigate 17 patients with DEE or EE with previous negative or inconclusive genetic testing by whole-exome sequencing (WES), leading to a definite diagnosis in about 59% of participants. Biallelic mutations caused most of the diagnosed cases (50%), and a pathogenic somatic mutation resulted in 10% of the subjects. The high diagnostic yield reached highlights the relevance of the scientific approach, the importance of the reverse phenotyping strategy, and the involvement of a dedicated multidisciplinary team. The study emphasizes the role of recessive and somatic variants, new genetic mechanisms, and the complexity of genotype–phenotype associations. In older patients, WES results could end invasive diagnostic procedures and allow a more accurate transition. Finally, an early pursued diagnosis is essential for comprehensive care of patients, precision approach, knowledge of prognosis, patient and family planning, and quality of life.
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17
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Song H, Yang J, Yu W. Promoter Hypomethylation of TGFBR3 as a Risk Factor of Alzheimer’s Disease: An Integrated Epigenomic-Transcriptomic Analysis. Front Cell Dev Biol 2022; 9:825729. [PMID: 35310542 PMCID: PMC8924075 DOI: 10.3389/fcell.2021.825729] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 12/29/2021] [Indexed: 11/13/2022] Open
Abstract
Alzheimer’s disease (AD) is characterized by the abnormal deposition of amyloid-β (Aβ) plaques and tau tangles in the brain and accompanied with cognitive impairment. However, the fundamental cause of this disease remains elusive. To elucidate the molecular processes related to AD, we carried out an integrated analysis utilizing gene expression microarrays (GSE36980 and GSE5281) and DNA methylation microarray (GSE66351) in temporal cortex of AD patients from the Gene Expression Omnibus (GEO) database. We totally discovered 409 aberrantly methylated and differentially expressed genes. These dysregulated genes were significantly enriched in biological processes including cell part morphogenesis, chemical synaptic transmission and regulation of Aβ formation. Through convergent functional genomic (CFG) analysis, expression cross-validation and clinicopathological correlation analysis, higher TGFBR3 level was observed in AD and positively correlated with Aβ accumulation. Meanwhile, the promoter methylation level of TGFBR3 was reduced in AD and negatively associated with Aβ level and advanced Braak stage. Mechanically, TGFBR3 might promote Aβ production by enhancing β- and γ-secretase activities. Further investigation revealed that TGFBR3 may exert its functions via Synaptic vesicle cycle, Calcium signaling pathway and MAPK signal pathway by regulating hub genes GNB1, GNG3, CDC5L, DYNC1H1 and FBXW7. Overall, our findings highlighted TGFBR3 as an AD risk gene and might be used as a diagnostic biomarker and therapeutic target for AD treatment.
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Affiliation(s)
- Hui Song
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education and Key Laboratory of Medical Molecular Biology of Guizhou Province, School of Basic Medical Sciences, Guizhou Medical University, Guiyang, China
| | - Jue Yang
- The State Key Laboratory of Functions and Applications of Medicinal Plants, Guizhou Medical University, Guiyang, China
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences, Guiyang, China
| | - Wenfeng Yu
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education and Key Laboratory of Medical Molecular Biology of Guizhou Province, School of Basic Medical Sciences, Guizhou Medical University, Guiyang, China
- *Correspondence: Wenfeng Yu,
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18
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Lattanzio K, Larijani M, Treat JR. Cutaneous mastocytosis in a child with a de novo GNB1 mutation. Pediatr Dermatol 2022; 39:328-329. [PMID: 35119134 DOI: 10.1111/pde.14913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 12/13/2021] [Accepted: 12/22/2021] [Indexed: 11/30/2022]
Abstract
In the last few years, de novo mutations in the GNB1 gene have been found to cause a neurodevelopmental disorder typically characterized by global developmental delay and hypotonia. Only 4 cases of maculopapular cutaneous mastocytosis in children with GNB1 mutations have been reported to date. Here, we describe another case of the condition with concomitant cutaneous mastocytosis.
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Affiliation(s)
- Katherine Lattanzio
- The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Mary Larijani
- Section of Pediatric Dermatology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - James R Treat
- The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Section of Pediatric Dermatology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
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19
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Rožmarić G, Hero M, Rački V, Vuletić V, Chudy D, Peterlin B. A case report of a novel GNB1 pathogenic variant and the response to deep brain stimulation. Acta Neurol Belg 2022; 123:603-605. [PMID: 35122616 DOI: 10.1007/s13760-022-01883-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 01/27/2022] [Indexed: 04/28/2023]
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20
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De Nittis P, Efthymiou S, Sarre A, Guex N, Chrast J, Putoux A, Sultan T, Raza Alvi J, Ur Rahman Z, Zafar F, Rana N, Rahman F, Anwar N, Maqbool S, Zaki MS, Gleeson JG, Murphy D, Galehdari H, Shariati G, Mazaheri N, Sedaghat A, Lesca G, Chatron N, Salpietro V, Christoforou M, Houlden H, Simonds WF, Pedrazzini T, Maroofian R, Reymond A. Inhibition of G-protein signalling in cardiac dysfunction of intellectual developmental disorder with cardiac arrhythmia (IDDCA) syndrome. J Med Genet 2021; 58:815-831. [PMID: 33172956 PMCID: PMC8639930 DOI: 10.1136/jmedgenet-2020-107015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 08/30/2020] [Accepted: 09/04/2020] [Indexed: 11/16/2022]
Abstract
BACKGROUND Pathogenic variants of GNB5 encoding the β5 subunit of the guanine nucleotide-binding protein cause IDDCA syndrome, an autosomal recessive neurodevelopmental disorder associated with cognitive disability and cardiac arrhythmia, particularly severe bradycardia. METHODS We used echocardiography and telemetric ECG recordings to investigate consequences of Gnb5 loss in mouse. RESULTS We delineated a key role of Gnb5 in heart sinus conduction and showed that Gnb5-inhibitory signalling is essential for parasympathetic control of heart rate (HR) and maintenance of the sympathovagal balance. Gnb5-/- mice were smaller and had a smaller heart than Gnb5+/+ and Gnb5+/- , but exhibited better cardiac function. Lower autonomic nervous system modulation through diminished parasympathetic control and greater sympathetic regulation resulted in a higher baseline HR in Gnb5-/- mice. In contrast, Gnb5-/- mice exhibited profound bradycardia on treatment with carbachol, while sympathetic modulation of the cardiac stimulation was not altered. Concordantly, transcriptome study pinpointed altered expression of genes involved in cardiac muscle contractility in atria and ventricles of knocked-out mice. Homozygous Gnb5 loss resulted in significantly higher frequencies of sinus arrhythmias. Moreover, we described 13 affected individuals, increasing the IDDCA cohort to 44 patients. CONCLUSIONS Our data demonstrate that loss of negative regulation of the inhibitory G-protein signalling causes HR perturbations in Gnb5-/- mice, an effect mainly driven by impaired parasympathetic activity. We anticipate that unravelling the mechanism of Gnb5 signalling in the autonomic control of the heart will pave the way for future drug screening.
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Affiliation(s)
| | - Stephanie Efthymiou
- Department of Neuromuscular Disorders, Queen Square Institute of Neurology, University College London, London, UK
| | - Alexandre Sarre
- Cardiovascular Assessment Facility, University of Lausanne, Lausanne, Switzerland
| | - Nicolas Guex
- Bioinformatics Competence Center, University of Lausanne, Lausanne, Switzerland
| | - Jacqueline Chrast
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Audrey Putoux
- Service de Génétique, Hopital Femme Mere Enfant, Bron, France
| | - Tipu Sultan
- Department of Pediatric Neurology, The Children's Hospital and Institute of Child Health, Lahore, Pakistan
| | - Javeria Raza Alvi
- Department of Pediatric Neurology, The Children's Hospital and Institute of Child Health, Lahore, Pakistan
| | - Zia Ur Rahman
- Department of Pediatric Neurology, The Children's Hospital and Institute of Child Health, Lahore, Pakistan
| | - Faisal Zafar
- Department of Paediatric Neurology, Children's Hospital and Institute of Child Health, Multan, Pakistan
| | - Nuzhat Rana
- Department of Paediatric Neurology, Children's Hospital and Institute of Child Health, Multan, Pakistan
| | - Fatima Rahman
- Department of Developmental-Behavioural Paediatrics, The Children's Hospital and Institute of Child Health, Lahore, Pakistan
| | - Najwa Anwar
- Department of Developmental-Behavioural Paediatrics, The Children's Hospital and Institute of Child Health, Lahore, Pakistan
| | - Shazia Maqbool
- Department of Developmental-Behavioural Paediatrics, The Children's Hospital and Institute of Child Health, Lahore, Pakistan
| | - Maha S Zaki
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Joseph G Gleeson
- Department of Neuroscience and Pediatrics, Howard Hughes Medical Institute, La Jolla, California, USA
| | - David Murphy
- Department of Neuromuscular Disorders, Queen Square Institute of Neurology, University College London, London, UK
| | - Hamid Galehdari
- Department of Genetics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahwaz, Iran (the Islamic Republic of)
| | - Gholamreza Shariati
- Department of Medical Genetics, Faculty of Medicine, Ahvaz Jondishapour University of Medical Sciences, Ahvaz, Iran (the Islamic Republic of)
| | - Neda Mazaheri
- Department of Genetics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahwaz, Iran (the Islamic Republic of)
| | - Alireza Sedaghat
- Health Research Institute, Diabetes Research Center, Ahvaz Jundishapur University of medical Sciences, Ahvaz, Iran (the Islamic Republic of)
| | - Gaetan Lesca
- Service de Genetique, Hospices Civils de Lyon, Lyon, France
| | - Nicolas Chatron
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
- Service de Genetique, Hospices Civils de Lyon, Lyon, France
| | - Vincenzo Salpietro
- Department of Neuromuscular Disorders, Queen Square Institute of Neurology, University College London, London, UK
| | - Marilena Christoforou
- Department of Neuromuscular Disorders, Queen Square Institute of Neurology, University College London, London, UK
| | - Henry Houlden
- Department of Neuromuscular Disorders, Queen Square Institute of Neurology, University College London, London, UK
| | - William F Simonds
- Metabolic Diseases Branch/NIDDK, National Institutes of Health, Bethesda, MD, USA
| | - Thierry Pedrazzini
- Experimental Cardiology Unit, Department of Cardiovascular Medicine, University of Lausanne, Lausanne, Switzerland
| | - Reza Maroofian
- Department of Neuromuscular Disorders, Queen Square Institute of Neurology, University College London, London, UK
| | - Alexandre Reymond
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
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21
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Da Silva JD, Costa MD, Almeida B, Lopes F, Maciel P, Teixeira-Castro A. Case Report: A Novel GNB1 Mutation Causes Global Developmental Delay With Intellectual Disability and Behavioral Disorders. Front Neurol 2021; 12:735549. [PMID: 34646230 PMCID: PMC8504539 DOI: 10.3389/fneur.2021.735549] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 08/27/2021] [Indexed: 01/26/2023] Open
Abstract
Diseases of neurodevelopment mostly exhibit neurological and psychiatric symptoms that go from very mild to extremely severe. While the etiology of most cases of neurodevelopmental disease is still unknown, the discovery of underlying genetic causes is rapidly increasing, with hundreds of genes being currently implicated as disease-causing. Here, we report a clinical case of a patient with a previously undiagnosed syndrome comprising severe global developmental delay, intellectual disability, and behavioral disorders (such as attention-deficit/hyperactivity disorder, autism spectrum disorder and recurrent bouts of aggressive behavior). After genetic testing, a pathogenic variant was detected in the GNB1 gene, which codes for the G-protein subunit β1. The detected variant (c.217G>A, p.A73T) has not been previously reported in any of the 58 published cases of GNB1 encephalopathy. However, it localizes to the mutational hotspot in exons 6 and 7 in which 88% of all missense mutations occur. An in silico model predicts that this mutation is likely to disrupt the WD40 domain of the GNB1 protein, which is required for its interaction with other G-proteins and, consequently, for downstream signal transduction. In conclusion, we reported an additional GNB1 encephalopathy patient, bearing a novel mutation, taking another step toward a better understanding of its clinical presentation and prospective development of treatments for the disease.
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Affiliation(s)
- Jorge Diogo Da Silva
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-Portuguese Government Associate Laboratory, Braga, Guimarães, Portugal.,Pediatrics Department, Hospital of Santa Maria Maior, Barcelos, Portugal
| | - Marta Daniela Costa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-Portuguese Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Bruno Almeida
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-Portuguese Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Fátima Lopes
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-Portuguese Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Patrícia Maciel
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-Portuguese Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Andreia Teixeira-Castro
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's-Portuguese Government Associate Laboratory, Braga, Guimarães, Portugal
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22
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Encephalopathy-causing mutations in Gβ 1 ( GNB1) alter regulation of neuronal GIRK channels. iScience 2021; 24:103018. [PMID: 34522861 PMCID: PMC8426278 DOI: 10.1016/j.isci.2021.103018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/04/2021] [Accepted: 08/18/2021] [Indexed: 11/24/2022] Open
Abstract
Mutations in the GNB1 gene, encoding the Gβ1 subunit of heterotrimeric G proteins, cause GNB1 Encephalopathy. Patients experience seizures, pointing to abnormal activity of ion channels or neurotransmitter receptors. We studied three Gβ1 mutations (K78R, I80N and I80T) using computational and functional approaches. In heterologous expression models, these mutations did not alter the coupling between G protein-coupled receptors to Gi/o, or the Gβγ regulation of the neuronal voltage-gated Ca2+ channel CaV2.2. However, the mutations profoundly affected the Gβγ regulation of the G protein-gated inwardly rectifying potassium channels (GIRK, or Kir3). Changes were observed in Gβ1 protein expression levels, Gβγ binding to cytosolic segments of GIRK subunits, and in Gβγ function, and included gain-of-function for K78R or loss-of-function for I80T/N, which were GIRK subunit-specific. Our findings offer new insights into subunit-dependent gating of GIRKs by Gβγ, and indicate diverse etiology of GNB1 Encephalopathy cases, bearing a potential for personalized treatment. GIRK channels are key players affected by GNB1 mutations under study (K78R and I80N/T) Effects of mutations (LoF or GoF) are channel subunit composition-specific The findings help to understand the GNB1 encephalopathy and to devise treatments The results yield new insights into mechanisms of Gβγ regulation of GIRKs
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23
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Hidden etiology of cerebral palsy: genetic and clinical heterogeneity and efficient diagnosis by next-generation sequencing. Pediatr Res 2021; 90:284-288. [PMID: 33177673 DOI: 10.1038/s41390-020-01250-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 09/30/2020] [Accepted: 10/16/2020] [Indexed: 12/21/2022]
Abstract
Cerebral palsy (CP) is a heterogeneous neurodevelopmental disorder that causes movement and postural disabilities. Recent research studies focused on genetic diagnosis in patients with CP of unknown etiology. The present study was carried out in 20 families with one family member affected with idiopathic CP. Chromosomal microarray and exome sequencing techniques were performed in all patients. Chromosomal microarray analysis did not show any pathological or probable pathological structural variant. However, the next-generation sequencing study showed a high diagnostic yield. We report 11/20 patients (55%) with different pathogenic or potentially pathogenic variants detected by exome sequencing analysis: five patients with mutations in genes related to hereditary spastic paraplegia, two with mutations in genes related to Aicardi-Goutières syndrome, three with mutations in genes related to developmental/epileptic encephalopathies, and one with a mutation in the PGK1 gene. The accurate and precise patients' selection, the use of a high-throughput genetic platform, the selection of adequate target genes, and the application of rigorous criteria for the clinical interpretation are the most important elements for a good diagnostic performance. Based on our findings, next-generation sequencing should be considered in patients with cryptogenic CP as the first line of genetic workup. IMPACT: Sequencing techniques in CP of uncertain etiology provides a diagnostic yield of 55%. The appropriate selection of cases optimizes the diagnostic yield. NGS facilitate better understanding of new phenotypes of certain genetic diseases.
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24
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Tan NB, Pagnamenta AT, Ferla MP, Gadian J, Chung BH, Chan MC, Fung JL, Cook E, Guter S, Boschann F, Heinen A, Schallner J, Mignot C, Keren B, Whalen S, Sarret C, Mittag D, Demmer L, Stapleton R, Saida K, Matsumoto N, Miyake N, Sheffer R, Mor-Shaked H, Barnett CP, Byrne AB, Scott HS, Kraus A, Cappuccio G, Brunetti-Pierri N, Iorio R, Di Dato F, Pais LS, Yeung A, Tan TY, Taylor JC, Christodoulou J, White SM. Recurrent de novo missense variants in GNB2 can cause syndromic intellectual disability. J Med Genet 2021; 59:511-516. [PMID: 34183358 DOI: 10.1136/jmedgenet-2020-107462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 03/25/2021] [Accepted: 04/23/2021] [Indexed: 11/04/2022]
Abstract
PURPOSE Binding proteins (G-proteins) mediate signalling pathways involved in diverse cellular functions and comprise Gα and Gβγ units. Human diseases have been reported for all five Gβ proteins. A de novo missense variant in GNB2 was recently reported in one individual with developmental delay/intellectual disability (DD/ID) and dysmorphism. We aim to confirm GNB2 as a neurodevelopmental disease gene, and elucidate the GNB2-associated neurodevelopmental phenotype in a patient cohort. METHODS We discovered a GNB2 variant in the index case via exome sequencing and sought individuals with GNB2 variants via international data-sharing initiatives. In silico modelling of the variants was assessed, along with multiple lines of evidence in keeping with American College of Medical Genetics and Genomics guidelines for interpretation of sequence variants. RESULTS We identified 12 unrelated individuals with five de novo missense variants in GNB2, four of which are recurrent: p.(Ala73Thr), p.(Gly77Arg), p.(Lys89Glu) and p.(Lys89Thr). All individuals have DD/ID with variable dysmorphism and extraneurologic features. The variants are located at the universally conserved shared interface with the Gα subunit, which modelling suggests weaken this interaction. CONCLUSION Missense variants in GNB2 cause a congenital neurodevelopmental disorder with variable syndromic features, broadening the spectrum of multisystem phenotypes associated with variants in genes encoding G-proteins.
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Affiliation(s)
- Natalie B Tan
- Victorian Clinical Genetics Services, Parkville, Victoria 3052, Australia.,Murdoch Children's Research Institute, Parkville, Victoria 3052, Australia.,Department of Paediatrics, The University of Melbourne, Parkville 3052, Victoria, Australia
| | - Alistair T Pagnamenta
- NIHR Oxford BRC, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Matteo P Ferla
- NIHR Oxford BRC, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Jonathan Gadian
- Department of Paediatric Neurology, John Radcliffe Hospital, Oxford, UK
| | - Brian Hy Chung
- Department of Paediatrics and Adolescent Medicine, LKS Faculty of Medicine, University of Hong Kong, Hong Kong
| | - Marcus Cy Chan
- Department of Paediatrics and Adolescent Medicine, LKS Faculty of Medicine, University of Hong Kong, Hong Kong
| | - Jasmine Lf Fung
- Department of Paediatrics and Adolescent Medicine, LKS Faculty of Medicine, University of Hong Kong, Hong Kong
| | - Edwin Cook
- Institute for Juvenile Research, Department of Psychiatry, University of Illinois at Chicago, Chicago 60608, Illinois, USA
| | - Stephen Guter
- Institute for Juvenile Research, Department of Psychiatry, University of Illinois at Chicago, Chicago 60608, Illinois, USA
| | - Felix Boschann
- Institute of Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, Berlin 13353, Germany
| | - Andre Heinen
- Carl Gustav Carus Faculty of Medicine, Children's Hospital, Technical University Dresden, Dresden, Germany
| | - Jens Schallner
- Department of Neuropediatrics, Carl Gustav Carus Faculty of Medicine, Children's Hospital, Technical University Dresden, Dresden, Germany
| | - Cyril Mignot
- Département de Génétique, Hôpital Pitié-Salpêtrière, APHP.Sorbonne Université, Paris, France
| | - Boris Keren
- Département de Génétique, Hôpital Pitié-Salpêtrière, APHP.Sorbonne Université, Paris, France
| | - Sandra Whalen
- UF de Génétique Clinique, Centre de Référence Maladies Rares Anomalies du développement et syndromes malformatifs, APHP.Sorbonne Université, Hôpital Armand Trousseau, Paris, France
| | - Catherine Sarret
- Service de génétique médicale, Hôpital Estaing, Centre hospitalo-universitaire de Clermont-Ferrand, 63003 Clermont-Ferrand, France
| | - Dana Mittag
- Division of Genetics, Levine Children's Hospital, Carolinas Medical Center, Atrium Health, Charlotte 28232-2861, North Carolina, USA
| | - Laurie Demmer
- Division of Genetics, Levine Children's Hospital, Carolinas Medical Center, Atrium Health, Charlotte 28232-2861, North Carolina, USA
| | - Rachel Stapleton
- Genetic Health Service NZ, Christchurch Hospital, Christchurch 8140, New Zealand
| | - Ken Saida
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Yokohama, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Yokohama, Japan
| | - Noriko Miyake
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Yokohama, Japan
| | - Ruth Sheffer
- Department of Human Genetics, Hadassah University Hospital, Jerusalem, Israel
| | - Hagar Mor-Shaked
- Department of Human Genetics, Hadassah University Hospital, Jerusalem, Israel
| | - Christopher P Barnett
- South Australian Clinical Genetics Service, Women's and Children's Hospital, North Adelaide 5006, South Australia, Australia
| | - Alicia B Byrne
- Department of Genetics and Molecular Pathology, Centre for Cancer Biology, Adelaide, South Australia, Australia.,UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Hamish S Scott
- Department of Genetics and Molecular Pathology, Centre for Cancer Biology, Adelaide, South Australia, Australia
| | - Alison Kraus
- Yorkshire Regional Genetics Service, Chapel Allerton Hospital, Leeds 0113 392 4455, UK.,Castle Hill Hospital, Cottingham, Hull 01482 622470, UK
| | - Gerarda Cappuccio
- Department of Translational Medicine, Section of Pediatrics, Federico II University Hospital, Naples, Italy.,Telethon Institute of Genetics and Medicine, Pozzuoli, Naples, Italy
| | - Nicola Brunetti-Pierri
- Department of Translational Medicine, Section of Pediatrics, Federico II University Hospital, Naples, Italy.,Telethon Institute of Genetics and Medicine, Pozzuoli, Naples, Italy
| | - Raffaele Iorio
- Department of Translational Medicine, Section of Pediatrics, Federico II University Hospital, Naples, Italy
| | - Fabiola Di Dato
- Department of Translational Medicine, Section of Pediatrics, Federico II University Hospital, Naples, Italy
| | - Lynn S Pais
- Center for Mendelian Genomics, Eli and Edythe L Broad Institute of Harvard and MIT, Cambridge, Massachusetts, USA
| | - Alison Yeung
- Victorian Clinical Genetics Services, Parkville, Victoria 3052, Australia.,Murdoch Children's Research Institute, Parkville, Victoria 3052, Australia.,Department of Paediatrics, The University of Melbourne, Parkville 3052, Victoria, Australia
| | - Tiong Y Tan
- Victorian Clinical Genetics Services, Parkville, Victoria 3052, Australia.,Murdoch Children's Research Institute, Parkville, Victoria 3052, Australia.,Department of Paediatrics, The University of Melbourne, Parkville 3052, Victoria, Australia
| | - Jenny C Taylor
- NIHR Oxford BRC, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - John Christodoulou
- Victorian Clinical Genetics Services, Parkville, Victoria 3052, Australia .,Murdoch Children's Research Institute, Parkville, Victoria 3052, Australia.,Department of Paediatrics, The University of Melbourne, Parkville 3052, Victoria, Australia
| | - Susan M White
- Victorian Clinical Genetics Services, Parkville, Victoria 3052, Australia .,Murdoch Children's Research Institute, Parkville, Victoria 3052, Australia.,Department of Paediatrics, The University of Melbourne, Parkville 3052, Victoria, Australia
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25
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Sub-genic intolerance, ClinVar, and the epilepsies: A whole-exome sequencing study of 29,165 individuals. Am J Hum Genet 2021; 108:965-982. [PMID: 33932343 DOI: 10.1016/j.ajhg.2021.04.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 04/08/2021] [Indexed: 12/23/2022] Open
Abstract
Both mild and severe epilepsies are influenced by variants in the same genes, yet an explanation for the resulting phenotypic variation is unknown. As part of the ongoing Epi25 Collaboration, we performed a whole-exome sequencing analysis of 13,487 epilepsy-affected individuals and 15,678 control individuals. While prior Epi25 studies focused on gene-based collapsing analyses, we asked how the pattern of variation within genes differs by epilepsy type. Specifically, we compared the genetic architectures of severe developmental and epileptic encephalopathies (DEEs) and two generally less severe epilepsies, genetic generalized epilepsy and non-acquired focal epilepsy (NAFE). Our gene-based rare variant collapsing analysis used geographic ancestry-based clustering that included broader ancestries than previously possible and revealed novel associations. Using the missense intolerance ratio (MTR), we found that variants in DEE-affected individuals are in significantly more intolerant genic sub-regions than those in NAFE-affected individuals. Only previously reported pathogenic variants absent in available genomic datasets showed a significant burden in epilepsy-affected individuals compared with control individuals, and the ultra-rare pathogenic variants associated with DEE were located in more intolerant genic sub-regions than variants associated with non-DEE epilepsies. MTR filtering improved the yield of ultra-rare pathogenic variants in affected individuals compared with control individuals. Finally, analysis of variants in genes without a disease association revealed a significant burden of loss-of-function variants in the genes most intolerant to such variation, indicating additional epilepsy-risk genes yet to be discovered. Taken together, our study suggests that genic and sub-genic intolerance are critical characteristics for interpreting the effects of variation in genes that influence epilepsy.
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26
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Tennakoon M, Senarath K, Kankanamge D, Ratnayake K, Wijayaratna D, Olupothage K, Ubeysinghe S, Martins-Cannavino K, Hébert TE, Karunarathne A. Subtype-dependent regulation of Gβγ signalling. Cell Signal 2021; 82:109947. [PMID: 33582184 PMCID: PMC8026654 DOI: 10.1016/j.cellsig.2021.109947] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/01/2021] [Accepted: 02/02/2021] [Indexed: 01/04/2023]
Abstract
G protein-coupled receptors (GPCRs) transmit information to the cell interior by transducing external signals to heterotrimeric G protein subunits, Gα and Gβγ subunits, localized on the inner leaflet of the plasma membrane. Though the initial focus was mainly on Gα-mediated events, Gβγ subunits were later identified as major contributors to GPCR-G protein signalling. A broad functional array of Gβγ signalling has recently been attributed to Gβ and Gγ subtype diversity, comprising 5 Gβ and 12 Gγ subtypes, respectively. In addition to displaying selectivity towards each other to form the Gβγ dimer, numerous studies have identified preferences of distinct Gβγ combinations for specific GPCRs, Gα subtypes and effector molecules. Importantly, Gβ and Gγ subtype-dependent regulation of downstream effectors, representing a diverse range of signalling pathways and physiological functions have been found. Here, we review the literature on the repercussions of Gβ and Gγ subtype diversity on direct and indirect regulation of GPCR/G protein signalling events and their physiological outcomes. Our discussion additionally provides perspective in understanding the intricacies underlying molecular regulation of subtype-specific roles of Gβγ signalling and associated diseases.
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Affiliation(s)
- Mithila Tennakoon
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA
| | - Kanishka Senarath
- Genetics and Molecular Biology Unit, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
| | - Dinesh Kankanamge
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA
| | - Kasun Ratnayake
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA; Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Dhanushan Wijayaratna
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA
| | - Koshala Olupothage
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA
| | - Sithurandi Ubeysinghe
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA
| | | | - Terence E Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QC H3G 1Y6, Canada.
| | - Ajith Karunarathne
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA.
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27
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Lansdon LA, Fleming EA, Viso FD, Sullivan BR, Saunders CJ. Second patient with GNB2-related neurodevelopmental disease: Further evidence for a gene-disease association. Eur J Med Genet 2021; 64:104243. [PMID: 33971351 DOI: 10.1016/j.ejmg.2021.104243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 04/28/2021] [Accepted: 05/02/2021] [Indexed: 11/30/2022]
Abstract
G-proteins are ubiquitously expressed heterotrimeric proteins consisting of α, β and γ subunits and mediate G-protein coupled receptor signalling cascades. The β subunit is encoded by one of five highly similar paralogs (GNB1-GNB5, accordingly). The developmental importance of G-proteins is highlighted by the clinical relevance of variants in genes such as GNB1, which cause severe neurodevelopmental disease (NDD). Recently the candidacy of GNB2 was raised in association with NDD in an individual with a de novo variant affecting a codon conserved across paralogs and recurrently mutated in GNB1-related disease, c.229G>A p.(Gly77Arg), in association with global developmental delay, intellectual disability and dysmorphic features. Here, we report a patient with strikingly similar facial features and NDD in association with a de novo GNB2 variant affecting the same codon, c.229G>T p.(Gly77Trp). In addition, this individual has epilepsy and overgrowth. Our report is the second to implicate a de novo GNB2 variant with a severe yet variable NDD.
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Affiliation(s)
- Lisa A Lansdon
- Department of Pathology and Laboratory Medicine, Children's Mercy-Kansas City, 2401 Gillham Road, Kansas City, MO, USA; Genomic Medicine Center, Children's Mercy-Kansas City, 2401 Gillham Road, Kansas City, MO, USA
| | - Emily A Fleming
- Division of Clinical Genetics, Children's Mercy-Kansas City, 2401 Gillham Road, Kansas City, MO, USA
| | - Florencia Del Viso
- Department of Pathology and Laboratory Medicine, Children's Mercy-Kansas City, 2401 Gillham Road, Kansas City, MO, USA; Genomic Medicine Center, Children's Mercy-Kansas City, 2401 Gillham Road, Kansas City, MO, USA
| | - Bonnie R Sullivan
- Division of Clinical Genetics, Children's Mercy-Kansas City, 2401 Gillham Road, Kansas City, MO, USA; University of Missouri-Kansas City, School of Medicine, 2411 Holmes Street, Kansas City, MO, USA
| | - Carol J Saunders
- Department of Pathology and Laboratory Medicine, Children's Mercy-Kansas City, 2401 Gillham Road, Kansas City, MO, USA; Genomic Medicine Center, Children's Mercy-Kansas City, 2401 Gillham Road, Kansas City, MO, USA; University of Missouri-Kansas City, School of Medicine, 2411 Holmes Street, Kansas City, MO, USA.
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28
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Pires G, Leitner D, Drummond E, Kanshin E, Nayak S, Askenazi M, Faustin A, Friedman D, Debure L, Ueberheide B, Wisniewski T, Devinsky O. Proteomic differences in the hippocampus and cortex of epilepsy brain tissue. Brain Commun 2021; 3:fcab021. [PMID: 34159317 DOI: 10.1093/braincomms/fcab021] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 12/10/2020] [Accepted: 12/11/2020] [Indexed: 12/22/2022] Open
Abstract
Epilepsy is a common neurological disorder affecting over 70 million people worldwide, with a high rate of pharmaco-resistance, diverse comorbidities including progressive cognitive and behavioural disorders, and increased mortality from direct (e.g. sudden unexpected death in epilepsy, accidents, drowning) or indirect effects of seizures and therapies. Extensive research with animal models and human studies provides limited insights into the mechanisms underlying seizures and epileptogenesis, and these have not translated into significant reductions in pharmaco-resistance, morbidities or mortality. To help define changes in molecular signalling networks associated with seizures in epilepsy with a broad range of aetiologies, we examined the proteome of brain samples from epilepsy and control cases. Label-free quantitative mass spectrometry was performed on the hippocampal cornu ammonis 1-3 region (CA1-3), frontal cortex and dentate gyrus microdissected from epilepsy and control cases (n = 14/group). Epilepsy cases had significant differences in the expression of 777 proteins in the hippocampal CA1 - 3 region, 296 proteins in the frontal cortex and 49 proteins in the dentate gyrus in comparison to control cases. Network analysis showed that proteins involved in protein synthesis, mitochondrial function, G-protein signalling and synaptic plasticity were particularly altered in epilepsy. While protein differences were most pronounced in the hippocampus, similar changes were observed in other brain regions indicating broad proteomic abnormalities in epilepsy. Among the most significantly altered proteins, G-protein subunit beta 1 (GNB1) was one of the most significantly decreased proteins in epilepsy in all regions studied, highlighting the importance of G-protein subunit signalling and G-protein-coupled receptors in epilepsy. Our results provide insights into common molecular mechanisms underlying epilepsy across various aetiologies, which may allow for novel targeted therapeutic strategies.
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Affiliation(s)
- Geoffrey Pires
- Comprehensive Epilepsy Center, New York University Grossman School of Medicine, New York, NY, USA.,Department of Neurology, Center for Cognitive Neurology, New York University Grossman School of Medicine, New York, NY, USA.,Alzheimer's and Prion Diseases Team, Paris Brain Institute, CNRS, UMR 7225, INSERM 1127, Sorbonne University UM75, Paris, France
| | - Dominique Leitner
- Comprehensive Epilepsy Center, New York University Grossman School of Medicine, New York, NY, USA
| | - Eleanor Drummond
- Department of Neurology, Center for Cognitive Neurology, New York University Grossman School of Medicine, New York, NY, USA.,Faculty of Medicine and Health, Brain and Mind Centre and School of Medical Sciences, University of Sydney, Sydney, Australia
| | - Evgeny Kanshin
- Proteomics Laboratory, Division of Advanced Research Technologies, New York University Grossman School of Medicine, New York, NY, USA
| | - Shruti Nayak
- Proteomics Laboratory, Division of Advanced Research Technologies, New York University Grossman School of Medicine, New York, NY, USA
| | - Manor Askenazi
- Biomedical Hosting LLC, USA.,Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY, USA
| | - Arline Faustin
- Department of Neurology, Center for Cognitive Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Daniel Friedman
- Comprehensive Epilepsy Center, New York University Grossman School of Medicine, New York, NY, USA
| | - Ludovic Debure
- Department of Neurology, Center for Cognitive Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Beatrix Ueberheide
- Department of Neurology, Center for Cognitive Neurology, New York University Grossman School of Medicine, New York, NY, USA.,Proteomics Laboratory, Division of Advanced Research Technologies, New York University Grossman School of Medicine, New York, NY, USA.,Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY, USA
| | - Thomas Wisniewski
- Department of Neurology, Center for Cognitive Neurology, New York University Grossman School of Medicine, New York, NY, USA.,Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, USA.,Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
| | - Orrin Devinsky
- Comprehensive Epilepsy Center, New York University Grossman School of Medicine, New York, NY, USA
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29
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Abstract
Mastocytosis is a heterogeneous group of disorders characterized by the accumulation of clonal mast cells in organs such as the skin and bone marrow. In contrast to adults, most affected children have only cutaneous involvement. This article reviews the molecular pathogenesis, skin findings, mast cell mediator-related symptoms, evaluation, and management of childhood-onset mastocytosis, noting differences from adult-onset disease. Current classification of cutaneous mastocytosis and the natural histories of different variants in pediatric patients are highlighted, with a focus on clinical manifestations with prognostic implications. A practical algorithm is provided to guide clinical assessment, laboratory and other investigations, and longitudinal monitoring, including recognition of hepatosplenomegaly as a marker of systemic disease and utilization of allele-specific quantitative PCR (ASqPCR) to detect KIT mutations in the peripheral blood. Updated information and consensus-based recommendations regarding possible triggers of mast-cell degranulation (e.g., physical, medications) are discussed, with an emphasis on patient-specific factors and avoiding excessive parental concern. Lastly, an individualized, stepwise approach to treatment of symptoms, skin-directed therapy, and potential use of kinase inhibitors for severe systemic disease is outlined.
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30
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Keller Sarmiento IJ, Mencacci NE. Genetic Dystonias: Update on Classification and New Genetic Discoveries. Curr Neurol Neurosci Rep 2021; 21:8. [PMID: 33564903 DOI: 10.1007/s11910-021-01095-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2021] [Indexed: 12/12/2022]
Abstract
PURPOSE OF REVIEW Since the advent of next-generation sequencing, the number of genes associated with dystonia has been growing exponentially. We provide here a comprehensive review of the latest genetic discoveries in the field of dystonia and discuss how the growing knowledge of biology underlying monogenic dystonias may influence and challenge current classification systems. RECENT FINDINGS Pathogenic variants in genes without previously confirmed roles in human disease have been identified in subjects affected by isolated or combined dystonia (KMT2B, VPS16, HPCA, KCTD17, DNAJC12, SLC18A2) and complex dystonia (SQSTM1, IRF2BPL, YY1, VPS41). Importantly, the classical distinction between isolated and combined dystonias has become harder to sustain since many genes have been shown to determine multiple dystonic presentations (e.g., ANO3, GNAL, ADCY5, and ATP1A3). In addition, a growing number of genes initially linked to other neurological phenotypes, such as developmental delay, epilepsy, or ataxia, are now recognized to cause prominent dystonia, occasionally in an isolated fashion (e.g., GNAO1, GNB1, SCN8A, RHOBTB2, and COQ8A). Finally, emerging analyses suggest biological convergence of genes linked to different dystonic phenotypes. While our knowledge on the genetic basis of monogenic dystonias has tremendously grown, their clinical boundaries are becoming increasingly blurry. The current phenotype-based classification may not reflect the molecular structure of the disease, urging the need for new systems based on shared biological pathways among dystonia-linked genes.
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Affiliation(s)
| | - Niccolò Emanuele Mencacci
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA.
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Lansdon LA, Saunders CJ. Genotype-phenotype correlation in GNB1-related neurodevelopmental disorder: Potential association of p.Leu95Pro with cleft palate. Am J Med Genet A 2021; 185:1341-1343. [PMID: 33427398 DOI: 10.1002/ajmg.a.62080] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 12/28/2020] [Accepted: 12/30/2020] [Indexed: 11/11/2022]
Affiliation(s)
- Lisa A Lansdon
- Department of Pathology and Laboratory Medicine, Children's Mercy-Kansas City, Kansas City, Missouri, USA.,Center for Pediatric Genomic Medicine, Children's Mercy-Kansas City, Kansas City, Missouri, USA
| | - Carol J Saunders
- Department of Pathology and Laboratory Medicine, Children's Mercy-Kansas City, Kansas City, Missouri, USA.,Center for Pediatric Genomic Medicine, Children's Mercy-Kansas City, Kansas City, Missouri, USA.,School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri, USA
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Gonzalez-Latapi P, Marotta N, Mencacci NE. Emerging and converging molecular mechanisms in dystonia. J Neural Transm (Vienna) 2021; 128:483-498. [DOI: 10.1007/s00702-020-02290-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 12/13/2020] [Indexed: 02/06/2023]
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G protein subunit β1 is an important mediator of the late stage of endochondral ossification. Biochem Biophys Res Commun 2020; 533:90-96. [PMID: 32928505 DOI: 10.1016/j.bbrc.2020.08.119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 08/31/2020] [Indexed: 01/14/2023]
Abstract
G protein signaling plays important roles in skeletal development. G protein subunit β1 (GNB1) is a component of the G protein complex and is associated with G protein signaling. In humans, GNB1 mutations cause global developmental and persistent growth delays and severe neurodevelopmental disability. Similarly, Gnb1-knockout (KO) mice display growth retardation with neural tube defects. These genetic studies raise the possibility that GNB1 regulates skeletal development. This study was designed to investigate the role of GNB1 in skeletal development using Gnb1-KO mice. Gnb1-KO mice showed dwarfism, shortening of limbs, and a decreased ossifying zone of long bones. In situ hybridization and RT-qPCR analyses revealed that Col10a1 and Mmp13 expression was reduced in long bones of Gnb1-KO mice, while Runx2, Osterix, Ihh, and Ppr expression levels were similar to those in wild-type littermates. Gnb1-KO-derived osteoblasts maintained calcification abilities and the expression levels of osteoblast marker genes were unaltered, indicating that osteoblast differentiation and function were not affected in Gnb1-KO mice. Taken together, our results show that GNB1 is required for the late stage of endochondral bone formation by regulating Col10a1 and Mmp13 expression.
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Schultz‐Rogers L, Masuho I, Pinto e Vairo F, Schmitz CT, Schwab TL, Clark KJ, Gunderson L, Pichurin PN, Wierenga K, Martemyanov KA, Klee EW. Haploinsufficiency as a disease mechanism in GNB1-associated neurodevelopmental disorder. Mol Genet Genomic Med 2020; 8:e1477. [PMID: 32918542 PMCID: PMC7667315 DOI: 10.1002/mgg3.1477] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 08/05/2020] [Accepted: 08/06/2020] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND GNB1 encodes a subunit of a heterotrimeric G-protein complex that transduces intracellular signaling cascades. Disruptions to the gene have previously been shown to be embryonic lethal in knockout mice and to cause complex neurodevelopmental disorders in humans. To date, the majority of variants associated with disease in humans have been missense variants in exons 5-7. METHODS Genetic sequencing was performed on two patients presenting with complex neurological phenotypes including intellectual disability, hypotonia, and in one patient seizures. Reported variants were assessed using RNA sequencing and functional BRET/BiFC assays. RESULTS A splice variant reported in patient 1 was confirmed to cause usage of a cryptic splice site leading to a truncated protein product. Patient 2 was reported to have a truncating variant. BRET and BiFC assays of both patient variants confirmed both were deficient in inducing GPCR-induced G protein activation due to lack of dimer formation with the Gγ subunit. CONCLUSION Here, we report two patients with functionally confirmed loss of function variants in GNB1 and neurodevelopmental phenotypes including intellectual disability, hypotonia, and seizures in one patient. These results suggest haploinsufficiency of GNB1 is a mechanism for neurodevelopmental disorders in humans.
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Affiliation(s)
| | - Ikuo Masuho
- Department of NeuroscienceThe Scripps Research InstituteJupiterFLUSA
| | - Filippo Pinto e Vairo
- Center for Individualized MedicineMayo ClinicRochesterMNUSA
- Department of Clinical GenomicsMayo ClinicRochesterMNUSA
| | | | - Tanya L. Schwab
- Department of Biochemistry and Molecular BiologyMayo ClinicRochesterMNUSA
| | - Karl J. Clark
- Department of Biochemistry and Molecular BiologyMayo ClinicRochesterMNUSA
| | | | | | - Klaas Wierenga
- Department of Medical GeneticsMayo ClinicJacksonvilleFLUSA
| | | | - Eric W. Klee
- Center for Individualized MedicineMayo ClinicRochesterMNUSA
- Department of Clinical GenomicsMayo ClinicRochesterMNUSA
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A three-year follow-up study evaluating clinical utility of exome sequencing and diagnostic potential of reanalysis. NPJ Genom Med 2020; 5:37. [PMID: 32963807 PMCID: PMC7484757 DOI: 10.1038/s41525-020-00144-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 08/14/2020] [Indexed: 01/05/2023] Open
Abstract
Exome sequencing (ES) has become one of the important diagnostic tools in clinical genetics with a reported diagnostic rate of 25–58%. Many studies have illustrated the diagnostic and immediate clinical impact of ES. However, up to 75% of individuals remain undiagnosed and there is scarce evidence supporting clinical utility beyond a follow-up period of >1 year. This is a 3-year follow-up analysis to our previous publication by Mak et al. (NPJ Genom. Med. 3:19, 2018), to evaluate the long-term clinical utility of ES and the diagnostic potential of exome reanalysis. The diagnostic yield of the initial study was 41% (43/104). Exome reanalysis in 46 undiagnosed individuals has achieved 12 new diagnoses. The additional yield compared with the initial analysis was at least 12% (increased from 41% to at least 53%). After a median follow-up period of 3.4 years, change in clinical management was observed in 72.2% of the individuals (26/36), leading to positive change in clinical outcome in four individuals (11%). There was a minimum healthcare cost saving of HKD$152,078 (USD$19,497; €17,282) annually for these four individuals. There were a total of six pregnancies from five families within the period. Prenatal diagnosis was performed in four pregnancies; one fetus was affected and resulted in termination. None of the parents underwent preimplantation genetic diagnosis. This 3-year follow-up study demonstrated the long-term clinical utility of ES at individual, familial and health system level, and the promising diagnostic potential of subsequent reanalysis. This highlights the benefits of implementing ES and regular reanalysis in the clinical setting.
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Vozdova M, Kubickova S, Pal K, Fröhlich J, Fictum P, Rubes J. Recurrent gene mutations detected in canine mast cell tumours by next generation sequencing. Vet Comp Oncol 2020; 18:509-518. [PMID: 31999054 DOI: 10.1111/vco.12572] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 01/17/2020] [Accepted: 01/24/2020] [Indexed: 12/12/2022]
Abstract
Genetic causes of canine mast cell tumours (MCTs), except for mutations in the KIT gene detected in some MCTs, are generally unknown. We used whole exome sequencing to reveal mutation spectra in canine MCTs. We detected somatic mutations in 87 genes including 10 genes recognized as human cancer drivers. Besides KIT, 14 other genes were recurrently mutated. Subsequently, we performed next generation sequencing of a panel of 50 selected genes in additional MCT samples. In this group, the most frequently altered gene was GNB1 showing a recurrent dinucleotide substitution at position of Gly116 in 30% of the MCT samples (n = 6/20) and Ile80 substitution accompanied by a splice region mutation in one case. We extended the study by analysis of the above mentioned GNB1 regions in additional MCT samples by Sanger sequencing, and assessed the overall prevalence of GNB1 mutations to 17.3% (n = 14/81), which is similar to the prevalence of KIT alterations. Our results indicate that GNB1 mutations are probably involved in canine MCT pathogenesis in both cutaneous and subcutaneous MCT cases. As opposed to KIT alterations, the presence of GNB1 mutations did not negatively affect survival times, and our data even showed a trend towards positive prognosis. If our results are confirmed in a larger number of MCTs, an extension of molecular testing of canine MCTs by GNB1 analysis would help to refine the molecular stratification of MCTs, and become useful for targeted treatment strategies.
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Affiliation(s)
- Miluse Vozdova
- Department of Genetics and Reproduction, Central European Institute of Technology, Veterinary Research Institute, Brno, Czech Republic
| | - Svatava Kubickova
- Department of Genetics and Reproduction, Central European Institute of Technology, Veterinary Research Institute, Brno, Czech Republic
| | - Karol Pal
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Jan Fröhlich
- Department of Genetics and Reproduction, Central European Institute of Technology, Veterinary Research Institute, Brno, Czech Republic
| | - Petr Fictum
- Department of Pathological Morphology and Parasitology, Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences Brno, Czech Republic
| | - Jiri Rubes
- Department of Genetics and Reproduction, Central European Institute of Technology, Veterinary Research Institute, Brno, Czech Republic
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Endo W, Ikemoto S, Togashi N, Miyabayashi T, Nakajima E, Hamano SI, Shibuya M, Sato R, Takezawa Y, Okubo Y, Inui T, Kato M, Sengoku T, Ogata K, Hamanaka K, Mizuguchi T, Miyatake S, Nakashima M, Matsumoto N, Haginoya K. Phenotype-genotype correlations in patients with GNB1 gene variants, including the first three reported Japanese patients to exhibit spastic diplegia, dyskinetic quadriplegia, and infantile spasms. Brain Dev 2020; 42:199-204. [PMID: 31735425 DOI: 10.1016/j.braindev.2019.10.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 08/19/2019] [Accepted: 10/21/2019] [Indexed: 10/25/2022]
Abstract
We report the first three Japanese patients with missense variants in the GNB1 gene. Patients exhibited severe dyskinetic quadriplegia with cortical blindness and epileptic spasms, West syndrome (but with good outcomes), and hypotonic quadriplegia that later developed into spastic diplegia. Whole-exome sequencing revealed two recurrent GNB1 variants (p.Leu95Pro and p.Ile80Thr) and one novel variant (p.Ser74Leu). A recent investigation revealed large numbers of patients with GNB1 variants. Functional studies of such variants and genotype-phenotype correlation are required to enable future precision medicine.
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Affiliation(s)
- Wakaba Endo
- Department of Pediatric Neurology, Miyagi Children's Hospital Hospital, Sendai 989-3126, Japan
| | - Satoru Ikemoto
- Division of Neurology, Saitama Children's Medical Center, Saitama 330-8777, Japan
| | - Noriko Togashi
- Department of Pediatric Neurology, Miyagi Children's Hospital Hospital, Sendai 989-3126, Japan
| | - Takuya Miyabayashi
- Department of Pediatric Neurology, Miyagi Children's Hospital Hospital, Sendai 989-3126, Japan
| | - Erika Nakajima
- Division of Neurology, Saitama Children's Medical Center, Saitama 330-8777, Japan
| | - Shin-Ichiro Hamano
- Division of Neurology, Saitama Children's Medical Center, Saitama 330-8777, Japan
| | - Moriei Shibuya
- Department of Pediatric Neurology, Miyagi Children's Hospital Hospital, Sendai 989-3126, Japan
| | - Ryo Sato
- Department of Pediatric Neurology, Miyagi Children's Hospital Hospital, Sendai 989-3126, Japan
| | - Yusuke Takezawa
- Department of Pediatric Neurology, Miyagi Children's Hospital Hospital, Sendai 989-3126, Japan
| | - Yukimune Okubo
- Department of Pediatric Neurology, Miyagi Children's Hospital Hospital, Sendai 989-3126, Japan
| | - Takehiko Inui
- Department of Pediatric Neurology, Miyagi Children's Hospital Hospital, Sendai 989-3126, Japan
| | - Mitsuhiro Kato
- Department of Pediatrics, Showa University School of Medicine, Tokyo 152-8555, Japan
| | - Toru Sengoku
- Department of Biochemistry, Graduate School of Medicine, Yokohama City University, Yokohama, Japan
| | - Kazuhiro Ogata
- Department of Biochemistry, Graduate School of Medicine, Yokohama City University, Yokohama, Japan
| | - Kohei Hamanaka
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Yokohama 236-0004, Japan
| | - Takeshi Mizuguchi
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Yokohama 236-0004, Japan
| | - Satoko Miyatake
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Yokohama 236-0004, Japan
| | - Mitsuko Nakashima
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Yokohama 236-0004, Japan; Department of Biochemistry, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Graduate School of Medicine, Yokohama City University, Yokohama 236-0004, Japan
| | - Kazuhiro Haginoya
- Department of Pediatric Neurology, Miyagi Children's Hospital Hospital, Sendai 989-3126, Japan.
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Malerba N, De Nittis P, Merla G. The Emerging Role of Gβ Subunits in Human Genetic Diseases. Cells 2019; 8:E1567. [PMID: 31817184 PMCID: PMC6952978 DOI: 10.3390/cells8121567] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/23/2019] [Accepted: 11/29/2019] [Indexed: 12/20/2022] Open
Abstract
Environmental stimuli are perceived and transduced inside the cell through the activation of signaling pathways. One common type of cell signaling transduction network is initiated by G-proteins. G-proteins are activated by G-protein-coupled receptors (GPCRs) and transmit signals from hormones, neurotransmitters, and other signaling factors, thus controlling a number of biological processes that include synaptic transmission, visual photoreception, hormone and growth factors release, regulation of cell contraction and migration, as well as cell growth and differentiation. G-proteins mainly act as heterotrimeric complexes, composed of alpha, beta, and gamma subunits. In the last few years, whole exome sequencing and biochemical studies have shown causality of disease-causing variants in genes encoding G-proteins and human genetic diseases. This review focuses on the G-protein β subunits and their emerging role in the etiology of genetically inherited rare diseases in humans.
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Affiliation(s)
- Natascia Malerba
- Division of Medical Genetics Unit, IRCCS Casa Sollievo della Sofferenza, Viale Cappuccini, 71013 San Giovanni Rotondo (FG), Italy;
| | - Pasquelena De Nittis
- Center for Integrative Genomics, University of Lausanne, CH-1015 Lausanne, Switzerland;
| | - Giuseppe Merla
- Division of Medical Genetics Unit, IRCCS Casa Sollievo della Sofferenza, Viale Cappuccini, 71013 San Giovanni Rotondo (FG), Italy;
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Fukuda T, Hiraide T, Yamoto K, Nakashima M, Kawai T, Yanagi K, Ogata T, Saitsu H. Exome reports A de novo GNB2 variant associated with global developmental delay, intellectual disability, and dysmorphic features. Eur J Med Genet 2019; 63:103804. [PMID: 31698099 DOI: 10.1016/j.ejmg.2019.103804] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 10/22/2019] [Accepted: 11/02/2019] [Indexed: 11/30/2022]
Abstract
Heterotrimeric G proteins are composed of α, β, and γ subunits and are involved in integrating signals between receptors and effector proteins. The 5 human Gβ proteins (encoded by GNB1, GNB2, GNB3, GNB4, and GNB5) are highly similar. Variants in GNB1 were identified as a genetic cause of developmental delay. De novo variant in GNB2 has recently been reported as a cause of sinus node dysfunction and atrioventricular block but not as a cause of developmental delay. Trio-based whole-exome sequencing was performed on an individual with global developmental delay, muscle hypotonia, multiple congenital joint contractures and dysmorphism such as brachycephalus, thick eyebrows, thin upper lip, micrognathia, prominent chin, and bilateral tapered fingers. We identified a de novo GNB2 variant c.229G>A, p.(Gly77Arg). Notably, pathogenic substitutions of the homologous Gly77 residue including an identical variant (p.Gly77Arg, p.Gly77Val, p.Gly77Ser, p.Gly77Ala) of GNB1, a paralog of GNB2, was reported in individuals with global developmental delay and hypotonia. Clinical features of our case overlap with those of GNB1 variants. Our study suggests that a GNB2 variant may be associated with syndromic global developmental delay.
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Affiliation(s)
- Tokiko Fukuda
- Department of Pediatrics, Hamamatsu University School of Medicine, Hamamatsu, Japan.
| | - Takuya Hiraide
- Department of Pediatrics, Hamamatsu University School of Medicine, Hamamatsu, Japan; Department of Biochemistry, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Kaori Yamoto
- Department of Pediatrics, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Mitsuko Nakashima
- Department of Biochemistry, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Tomoko Kawai
- Department of Maternal-Fetal Biology and National Research Institute for Child Health and Development, Tokyo, Japan
| | - Kumiko Yanagi
- Department of Genome Medicine, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Tsutomu Ogata
- Department of Pediatrics, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Hirotomo Saitsu
- Department of Biochemistry, Hamamatsu University School of Medicine, Hamamatsu, Japan
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40
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Genetic intolerance analysis as a tool for protein science. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1862:183058. [PMID: 31494120 DOI: 10.1016/j.bbamem.2019.183058] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Revised: 08/21/2019] [Accepted: 08/30/2019] [Indexed: 01/04/2023]
Abstract
Recent advances in whole genome and exome sequencing have dramatically increased the database of human gene variations. There are now enough sequenced human exomes and genomes to begin to identify gene variations that are notable because they are NOT observed in sequenced human genomes, apparently because they are subject to "purifying selection", exemplifying genetic intolerance. Such "dysprocreative" gene variations are embryonic lethal or prevent reproduction through any one of a number of possible mechanisms. Here we review an emerging quantitative approach, "Missense Tolerance Ratio" (MTR) analysis, that is used to assess protein-encoding gene (cDNA) sequence intolerance to missense mutations based on analysis of the >100 K and growing number of currently available human genome and exome sequences. This approach is already useful for analyzing intolerance to mutations in cDNA segments with a resolution on the order of 90 bases. Moreover, as the number of sequenced genomes/exomes increases by orders of magnitude it may eventually be possible to assess mutational tolerance in a statistically robust manner at or near single site resolution. Here we focus on how cDNA intolerance analysis complements other bioinformatic methods to illuminate structure-folding-function relationships for the encoded proteins. A set of disease-linked membrane proteins is employed to provide examples.
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41
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Jones HF, Morales-Briceño H, Barwick K, Lewis J, Sanchis-Juan A, Raymond FL, Stewart K, Waugh MC, Mahant N, Kurian MA, Dale RC, Mohammad SS. Myoclonus-dystonia caused by GNB1 mutation responsive to deep brain stimulation. Mov Disord 2019; 34:1079-1080. [PMID: 31034681 DOI: 10.1002/mds.27708] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 04/02/2019] [Accepted: 04/14/2019] [Indexed: 11/06/2022] Open
Affiliation(s)
- Hannah F Jones
- Neurology Department, The Children's Hospital at Westmead Clinical School, University of Sydney, New South Wales, Australia.,Kids Neuroscience Centre, Kids Research Institute, The Children's Hospital at Westmead, New South Wales, Australia
| | - Hugo Morales-Briceño
- Movement Disorders Unit, Neurology Department, Westmead Hospital, New South Wales, Australia
| | - Katy Barwick
- Molecular Neurosciences, Developmental Neurosciences, University College London Great Ormond St Institute of Child Health, London, UK
| | - Jennifer Lewis
- Kids Rehab, The Children's Hospital at Westmead, New South Wales, Australia
| | - Alba Sanchis-Juan
- Department of Haematology, University of Cambridge, National Health Service Blood and Transplant Centre, Cambridge, UK.,National Institute for Health Research BioResource, Cambridge University Hospitals National Health Service Foundation Trust, Cambridge Biomedical Campus, Cambridge, UK
| | - F Lucy Raymond
- Department of Medical Genetics, University of Cambridge, Cambridge, UK
| | - Kirsty Stewart
- Kids Rehab, The Children's Hospital at Westmead, New South Wales, Australia.,Discipline of Paediatrics and Child Health, University of Sydney, New South Wales, Australia
| | - Mary-Clare Waugh
- Kids Rehab, The Children's Hospital at Westmead, New South Wales, Australia.,Discipline of Paediatrics and Child Health, University of Sydney, New South Wales, Australia
| | - Neil Mahant
- Movement Disorders Unit, Neurology Department, Westmead Hospital, New South Wales, Australia
| | - Manju A Kurian
- Molecular Neurosciences, Developmental Neurosciences, University College London Great Ormond St Institute of Child Health, London, UK.,Department of Neurology, Great Ormond St Hospital for Children, London, UK
| | - Russell C Dale
- Neurology Department, The Children's Hospital at Westmead Clinical School, University of Sydney, New South Wales, Australia.,Kids Neuroscience Centre, Kids Research Institute, The Children's Hospital at Westmead, New South Wales, Australia
| | - Shekeeb S Mohammad
- Neurology Department, The Children's Hospital at Westmead Clinical School, University of Sydney, New South Wales, Australia.,Kids Neuroscience Centre, Kids Research Institute, The Children's Hospital at Westmead, New South Wales, Australia
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PDE10A mutations help to unwrap the neurobiology of hyperkinetic disorders. Cell Signal 2019; 60:31-38. [PMID: 30951862 DOI: 10.1016/j.cellsig.2019.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 03/31/2019] [Accepted: 04/01/2019] [Indexed: 12/31/2022]
Abstract
The dual-specific cAMP/cGMP phosphodiesterase PDE10A is exclusively localised to regions of the brain and specific cell types that control crucial brain circuits and behaviours. The downside to this expression pattern is that PDE10A is also positioned to be a key player in pathology when its function is perturbed. The last decade of research has seen a clear role emerge for PDE10A inhibition in modifying behaviours in animal models of psychosis and Huntington's disease. Unfortunately, this has not translated to the human diseases as expected. More recently, a series of families with hyperkinetic movement disorders have been identified with mutations altering the PDE10A protein sequence. As these mutations have been analysed and characterised in other model systems, we are beginning to learn more about PDE10A function and perhaps catch a glimpse into how PDE10A activity could be modified for therapeutic benefit.
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