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Nakane S, Koike H, Hayashi T, Nakatsuji Y. Autoimmune Autonomic Neuropathy: From Pathogenesis to Diagnosis. Int J Mol Sci 2024; 25:2296. [PMID: 38396973 PMCID: PMC10889307 DOI: 10.3390/ijms25042296] [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: 01/19/2024] [Revised: 02/09/2024] [Accepted: 02/12/2024] [Indexed: 02/25/2024] Open
Abstract
Autoimmune autonomic ganglionopathy (AAG) is a disease of autonomic failure caused by ganglionic acetylcholine receptor (gAChR) autoantibodies. Although the detection of autoantibodies is important for distinguishing the disease from other neuropathies that present with autonomic dysfunction, other factors are important for accurate diagnosis. Here, we provide a comprehensive review of the clinical features of AAG, highlighting differences in clinical course, clinical presentation, and laboratory findings from other neuropathies presenting with autonomic symptoms. The first step in diagnosing AAG is careful history taking, which should reveal whether the mode of onset is acute or chronic, followed by an examination of the time course of disease progression, including the presentation of autonomic and extra-autonomic symptoms. AAG is a neuropathy that should be differentiated from other neuropathies when the patient presents with autonomic dysfunction. Immune-mediated neuropathies, such as acute autonomic sensory neuropathy, are sometimes difficult to differentiate, and therefore, differences in clinical and laboratory findings should be well understood. Other non-neuropathic conditions, such as postural orthostatic tachycardia syndrome, chronic fatigue syndrome, and long COVID, also present with symptoms similar to those of AAG. Although often challenging, efforts should be made to differentiate among the disease candidates.
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Affiliation(s)
- Shunya Nakane
- Department of Neurology, Faculty of Medicine, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Haruki Koike
- Division of Neurology, Department of Internal Medicine, Faculty of Medicine, Saga University, Saga 849-8501, Japan
| | - Tomohiro Hayashi
- Department of Neurology, Faculty of Medicine, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Yuji Nakatsuji
- Department of Neurology, Faculty of Medicine, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
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Yarikipati P, Jonusaite S, Pleinis JM, Dominicci Cotto C, Sanchez-Hernandez D, Morrison DE, Goyal S, Schellinger J, Pénalva C, Curtiss J, Rodan AR, Jenny A. Unanticipated domain requirements for Drosophila Wnk kinase in vivo. PLoS Genet 2023; 19:e1010975. [PMID: 37819975 PMCID: PMC10593226 DOI: 10.1371/journal.pgen.1010975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 10/23/2023] [Accepted: 09/14/2023] [Indexed: 10/13/2023] Open
Abstract
WNK (With no Lysine [K]) kinases have critical roles in the maintenance of ion homeostasis and the regulation of cell volume. Their overactivation leads to pseudohypoaldosteronism type II (Gordon syndrome) characterized by hyperkalemia and high blood pressure. More recently, WNK family members have been shown to be required for the development of the nervous system in mice, zebrafish, and flies, and the cardiovascular system of mice and fish. Furthermore, human WNK2 and Drosophila Wnk modulate canonical Wnt signaling. In addition to a well-conserved kinase domain, animal WNKs have a large, poorly conserved C-terminal domain whose function has been largely mysterious. In most but not all cases, WNKs bind and activate downstream kinases OSR1/SPAK, which in turn regulate the activity of various ion transporters and channels. Here, we show that Drosophila Wnk regulates Wnt signaling and cell size during the development of the wing in a manner dependent on Fray, the fly homolog of OSR1/SPAK. We show that the only canonical RF(X)V/I motif of Wnk, thought to be essential for WNK interactions with OSR1/SPAK, is required to interact with Fray in vitro. However, this motif is unexpectedly dispensable for Fray-dependent Wnk functions in vivo during fly development and fluid secretion in the Malpighian (renal) tubules. In contrast, a structure function analysis of Wnk revealed that the less-conserved C-terminus of Wnk, that recently has been shown to promote phase transitions in cell culture, is required for viability in vivo. Our data thus provide novel insights into unexpected in vivo roles of specific WNK domains.
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Affiliation(s)
- Prathibha Yarikipati
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, New York, United States of America
| | - Sima Jonusaite
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, United States of America
| | - John M. Pleinis
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, United States of America
| | - Carihann Dominicci Cotto
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, New York, United States of America
| | - David Sanchez-Hernandez
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, New York, United States of America
| | - Daryl E. Morrison
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, United States of America
| | - Suhani Goyal
- Department of Internal Medicine, Division of Nephrology, University of Texas Southwestern, Dallas, Texas, United States of America
| | - Jeffrey Schellinger
- Department of Internal Medicine, Division of Nephrology, University of Texas Southwestern, Dallas, Texas, United States of America
| | - Clothilde Pénalva
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, United States of America
| | - Jennifer Curtiss
- Department of Cell & Developmental Biology, New Mexico State University, Las Cruces, New Mexico, United States of America
| | - Aylin R. Rodan
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, United States of America
- Department of Internal Medicine, Division of Nephrology and Hypertension, University of Utah, Salt Lake City, Utah, United States of America
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, United States of America
- Medical Service, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah, United States of America
| | - Andreas Jenny
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, New York, United States of America
- Department of Genetics, Albert Einstein College of Medicine, New York, New York, United States of America
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3
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Li L, Jia C, Tang Y, Kong Y, Xia Y, Ma L. Novel Gross Deletion Mutations in NTRK1 Gene Associated With Congenital Insensitivity to Pain With Anhidrosis. Front Pediatr 2021; 9:638190. [PMID: 33748046 PMCID: PMC7969531 DOI: 10.3389/fped.2021.638190] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Accepted: 01/20/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Congenital insensitivity to pain with anhidrosis (CIPA) is a rare inherited autosomal recessive disorder characterized by insensitivity to noxious stimuli, anhidrosis, recurrent fever, and intellectual disability. CIPA is mainly caused by mutations in the neurotrophic tyrosine kinase receptor type 1 gene (NTRK1). This study aims to identify pathogenic mutations underlying CIPA in two unrelated Chinese families. Methods: DNA was extracted from blood samples of patients and their available family members and subjected to whole exome sequencing (WES). Real-time PCR (qPCR), Gap-PCR, and Sanger sequencing were applied to verify the identified variants. Result: We found novel compound gross deletion mutations [exon1-6 del (g.1-1258_10169del); exon5-7 del (g.6995_11999del)] of NTRK1 (MIM 191315) gene in family 1 and the compound heterozygous mutations [c.851-33T>A; exon5-7 del (g.6995_11999del)] in family 2. Interestingly, we discovered the intragenic novel gross deletion [exon5-7 del (g.6995_11999del)] mediated by recombination between Alu elements. Conclusions: The present study highlights two rare gross deletion mutations in the NTRK1 gene associated with CIPA in two unrelated Chinese families. The deletion of exon1-6 (g.1-1258_10169del) is thought to be the largest NTRK1 deletion reported to date. Our findings expand the mutation spectrum of NTRK1 mutations in the Chinese and could be useful for prenatal interventions and more precise pharmacological treatments to patients. WES conducted in our study is a convenient and useful tool for clinical diagnosis of CIPA and other associated disorders.
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Affiliation(s)
- Lulu Li
- Department of Newborn Screening Center, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing Maternal and Child Health Care Hospital, Beijing, China
| | - Chao Jia
- Department of Neonatology, Hebei Provincial Children's Hospital, Shijiazhuang, China
| | - Yue Tang
- Department of Newborn Screening Center, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing Maternal and Child Health Care Hospital, Beijing, China
| | - Yuanyuan Kong
- Department of Newborn Screening Center, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing Maternal and Child Health Care Hospital, Beijing, China
| | - Yaofang Xia
- Department of Neonatology, Hebei Provincial Children's Hospital, Shijiazhuang, China
| | - Li Ma
- Department of Neonatology, Hebei Provincial Children's Hospital, Shijiazhuang, China
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4
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Prabhu S, Fortier K, Newsome L, Reebye UN. Office-Based Anesthetic and Oral Surgical Management of a Child With Hereditary Sensory Autonomic Neuropathy Type IV: A Case Report. Anesth Prog 2018; 65:181-186. [PMID: 30235436 DOI: 10.2344/anpr-65-03-07] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Hereditary sensory and autonomic neuropathy type IV (HSAN IV), or congenital insensitivity to pain with anhidrosis, is an exceptionally rare genetic disorder that results in the complete loss of pain and temperature sensation as well as anhidrosis. Anesthetic management of these patients can be difficult because of significantly increased risks during general anesthesia. Literature on perioperative anesthetic management is typically written in the context of a hospital setting. As such, our case presents a unique report on the anesthetic management of a HSAN IV patient who presented for extraction of 2 teeth in an office-based setting. In determining how to safely manage the procedure, we decided against general anesthesia as we lacked the facilities and equipment to safely handle previously reported complications. We were successful in providing sedation with nitrous oxide in oxygen and applying 20% benzocaine topical ointment on the surgical site in lieu of administering general anesthesia. We had an anesthesiologist present and obtained intravenous access prior to the surgery to help manage any complications. This report provides support that simple dental extractions can be accomplished safely in the HSAN IV patient in the office-based setting, thereby avoiding unnecessary risk.
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Affiliation(s)
- Shamit Prabhu
- Master of Physiology Candidate, North Carolina State University, Raleigh, North Carolina
| | - Kevin Fortier
- DMD Candidate, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts
| | - Lisa Newsome
- Anesthesiologist; Triangle Implant Center, Durham, North Carolina
| | - Uday N Reebye
- Oral and Maxillofacial Surgeon, Triangle Implant Center, Durham, North Carolina
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5
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Charcot Marie Tooth 2B Peripheral Sensory Neuropathy: How Rab7 Mutations Impact NGF Signaling? Int J Mol Sci 2017; 18:ijms18020324. [PMID: 28165391 PMCID: PMC5343860 DOI: 10.3390/ijms18020324] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 01/10/2017] [Accepted: 01/15/2017] [Indexed: 12/12/2022] Open
Abstract
Charcot-Marie-Tooth 2B peripheral sensory neuropathy (CMT2B) is a debilitating autosomal dominant hereditary sensory neuropathy. Patients with this disease lose pain sensation and frequently need amputation. Axonal dysfunction and degeneration of peripheral sensory neurons is a major clinical manifestation of CMT2B. However, the cellular and molecular pathogenic mechanisms remain undefined. CMT2B is caused by missense point mutations (L129F, K157N, N161T/I, V162M) in Rab7 GTPase. Strong evidence suggests that the Rab7 mutation(s) enhances the cellular levels of activated Rab7 proteins, thus resulting in increased lysosomal activity and autophagy. As a consequence, trafficking and signaling of neurotrophic factors such as nerve growth factor (NGF) in the long axons of peripheral sensory neurons are particularly vulnerable to premature degradation. A “gain of toxicity” model has, thus, been proposed based on these observations. However, studies of fly photo-sensory neurons indicate that the Rab7 mutation(s) causes a “loss of function”, resulting in haploinsufficiency. In the review, we summarize experimental evidence for both hypotheses. We argue that better models (rodent animals and human neurons) of CMT2B are needed to precisely define the disease mechanisms.
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Abstract
WNK (With-No-Lysine (K)) kinases are serine-threonine kinases characterized by an atypical placement of a catalytic lysine within the kinase domain. Mutations in human WNK1 or WNK4 cause an autosomal dominant syndrome of hypertension and hyperkalemia, reflecting the fact that WNK kinases are critical regulators of renal ion transport processes. Here, the role of WNKs in the regulation of ion transport processes in vertebrate and invertebrate renal function, cellular and organismal osmoregulation, and cell migration and cerebral edema will be reviewed, along with emerging literature demonstrating roles for WNKs in cardiovascular and neural development, Wnt signaling, and cancer. Conserved roles for these kinases across phyla are emphasized.
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Affiliation(s)
| | - Andreas Jenny
- Albert Einstein College of Medicine, New York, NY, United States.
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7
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Lunn M, Hanna M, Howard R, Parton M, Rahman S, Reilly M, Sidle K, Turner C. Nerve and Muscle Disease. Neurology 2016. [DOI: 10.1002/9781118486160.ch10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
| | | | | | | | | | | | - Katie Sidle
- National Hospital for Neurology & Neurosurgery
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8
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Nagy V, Cole T, Van Campenhout C, Khoung TM, Leung C, Vermeiren S, Novatchkova M, Wenzel D, Cikes D, Polyansky AA, Kozieradzki I, Meixner A, Bellefroid EJ, Neely GG, Penninger JM. The evolutionarily conserved transcription factor PRDM12 controls sensory neuron development and pain perception. Cell Cycle 2016; 14:1799-808. [PMID: 25891934 DOI: 10.1080/15384101.2015.1036209] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
PR homology domain-containing member 12 (PRDM12) belongs to a family of conserved transcription factors implicated in cell fate decisions. Here we show that PRDM12 is a key regulator of sensory neuronal specification in Xenopus. Modeling of human PRDM12 mutations that cause hereditary sensory and autonomic neuropathy (HSAN) revealed remarkable conservation of the mutated residues in evolution. Expression of wild-type human PRDM12 in Xenopus induced the expression of sensory neuronal markers, which was reduced using various human PRDM12 mutants. In Drosophila, we identified Hamlet as the functional PRDM12 homolog that controls nociceptive behavior in sensory neurons. Furthermore, expression analysis of human patient fibroblasts with PRDM12 mutations uncovered possible downstream target genes. Knockdown of several of these target genes including thyrotropin-releasing hormone degrading enzyme (TRHDE) in Drosophila sensory neurons resulted in altered cellular morphology and impaired nociception. These data show that PRDM12 and its functional fly homolog Hamlet are evolutionary conserved master regulators of sensory neuronal specification and play a critical role in pain perception. Our data also uncover novel pathways in multiple species that regulate evolutionary conserved nociception.
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Key Words
- BSA, bovine serum albumin
- Brn3d, brain 3d
- CGNL1, cyclin L1
- ChIP, chromatin immunoprecipitation
- DAPI, 4′,6-diamidino-2-phenylindole
- DDK, DYKDDDDK epitope
- Drgx, dorsal root ganglia homeobox
- ECL, enhanced chemiluminescence
- En1, engrailed-1
- FDR, false discovery rate
- FPKM, fragments per kilobase exon
- GAPDH, glyceraldehyde 3-phospate dehydrogenase
- GEO, gene expression omnibus
- GFP, green fluorescent protein
- HEK293, human embryonic kidney cell 293
- HRP, horseraddish peroxidase
- HSAN, hereditary and sensory autonomic neuropathy
- Hamlet
- Hmx3, H6 family homeobox 3
- IL1R1, interleukin 1 receptor type 1
- MO, morpholino oligonucleotide
- NBT/BCIP, nitro blue tetrazolium / 5-bromo-4-chloro-3-indolyl-phosphate
- PBS, phosphate buffered saline
- PDB, protein data base
- PMID, pubmed identification.
- PRDM12
- PRDM12, PR homology domain-containing member 12
- RA, retinoic acid
- RT-qPCR, real-time quantitative polymerase chain reaction
- S1PR1, Sphi8ngosine-1-phosphate receptor 1
- SET, Su(var)3–9 and ‘Enhancer of zeste’
- Sncg, Synuclein Gamma (Breast Cancer-Specific Protein 1)
- TRH(DE), tryrotropin-releasing hormone degrading enzyme
- TRHDE
- TRHDE, tyrotropin-releasing hormone degrading enzyme
- Tlx3, T-cell leukemia homeobox 3
- nociception
- pCMV6, plasmid cytomegalovirus
- sensory neurons
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Affiliation(s)
- Vanja Nagy
- IMBA-Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria; UNSW Medicine, Sydney, Australia
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9
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Abstract
• Individual variability in pain perception and differences in the efficacy of analgesic drugs are complex phenomena and are partly genetically predetermined. • Analgesics act in various ways on the peripheral and central pain pathways and are regarded as one of the most valuable but equally dangerous groups of medications. • While pharmacokinetic properties of drugs, metabolism in particular, have been scrutinised by genotype–phenotype correlation studies, the clinical significance of inherited variants in genes governing pharmacodynamics of analgesics remains largely unexplored (apart from the µ-opioid receptor). • Lack of replication of the findings from one study to another makes meaningful personalised analgesic regime still a distant future. • This narrative review will focus on findings related to pharmacogenetics of commonly used analgesic medications and highlight authors’ views on future clinical implications of pharmacogenetics in the context of pharmacological treatment of chronic pain.
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Affiliation(s)
- Roman Cregg
- UCL Centre for Anaesthesia, Critical Care & Pain Medicine, London, UK ; Royal Marsden NHS Foundation Trust, London, UK
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Caglayan AO, Comu S, Baranoski JF, Parman Y, Kaymakçalan H, Akgumus GT, Caglar C, Dolen D, Erson-Omay EZ, Harmanci AS, Mishra-Gorur K, Freeze HH, Yasuno K, Bilguvar K, Gunel M. NGLY1 mutation causes neuromotor impairment, intellectual disability, and neuropathy. Eur J Med Genet 2014; 58:39-43. [PMID: 25220016 DOI: 10.1016/j.ejmg.2014.08.008] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 08/18/2014] [Indexed: 11/26/2022]
Abstract
N-glycanase 1 (NGLY1) is a conserved enzyme that is responsible for the deglycosylation of misfolded N-glycosylated proteins in the cytoplasm prior to their proteasome-mediated degradation. Disruption of this degradation process has been associated with various neurologic diseases including amyotrophic lateral sclerosis and Parkinson's disease. Here, we describe two siblings with neuromotor impairment, apparent intellectual disability, corneal opacities, and neuropathy who were found to possess a novel homozygous frame-shift mutation due to a 4 base pair deletion in NGLY1 (c.1533_1536delTCAA, p.Asn511LysfsX51). We hypothesize that this mutation likely limits the capability of neuronal cells to respond to stress due to accumulation of misfolded proteins, thereby impairing their survival and resulting in progressive loss of neurological function.
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Affiliation(s)
- Ahmet Okay Caglayan
- Departments of Neurosurgery, Neurobiology and Genetics, Yale Program in Neurogenetics, Yale School of Medicine, New Haven 06510, CT, USA.
| | - Sinan Comu
- Department of Pediatrics, Division of Pediatric Neurology, Sisli, Memorial Hospital, Istanbul 34385, Turkey
| | - Jacob F Baranoski
- Departments of Neurosurgery, Neurobiology and Genetics, Yale Program in Neurogenetics, Yale School of Medicine, New Haven 06510, CT, USA
| | - Yesim Parman
- Department of Neurology, Istanbul University, Faculty of Medicine, Istanbul 34098, Turkey
| | - Hande Kaymakçalan
- Department of Genetics and Bioinformatics, Faculty of Engineering, Bahcesehir University, Istanbul 34353, Turkey
| | - Gozde Tugce Akgumus
- Departments of Neurosurgery, Neurobiology and Genetics, Yale Program in Neurogenetics, Yale School of Medicine, New Haven 06510, CT, USA
| | - Caner Caglar
- Departments of Neurosurgery, Neurobiology and Genetics, Yale Program in Neurogenetics, Yale School of Medicine, New Haven 06510, CT, USA
| | - Duygu Dolen
- Departments of Neurosurgery, Neurobiology and Genetics, Yale Program in Neurogenetics, Yale School of Medicine, New Haven 06510, CT, USA
| | - Emine Zeynep Erson-Omay
- Departments of Neurosurgery, Neurobiology and Genetics, Yale Program in Neurogenetics, Yale School of Medicine, New Haven 06510, CT, USA
| | - Akdes Serin Harmanci
- Departments of Neurosurgery, Neurobiology and Genetics, Yale Program in Neurogenetics, Yale School of Medicine, New Haven 06510, CT, USA
| | - Ketu Mishra-Gorur
- Departments of Neurosurgery, Neurobiology and Genetics, Yale Program in Neurogenetics, Yale School of Medicine, New Haven 06510, CT, USA
| | - Hudson H Freeze
- Genetic Disease Program, Sanford-Burnham Medical Research Institute, La Jolla 92037, CA, USA
| | - Katsuhito Yasuno
- Departments of Neurosurgery, Neurobiology and Genetics, Yale Program in Neurogenetics, Yale School of Medicine, New Haven 06510, CT, USA
| | - Kaya Bilguvar
- Departments of Neurosurgery, Neurobiology and Genetics, Yale Program in Neurogenetics, Yale School of Medicine, New Haven 06510, CT, USA
| | - Murat Gunel
- Departments of Neurosurgery, Neurobiology and Genetics, Yale Program in Neurogenetics, Yale School of Medicine, New Haven 06510, CT, USA.
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11
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Schabhüttl M, Wieland T, Senderek J, Baets J, Timmerman V, De Jonghe P, Reilly MM, Stieglbauer K, Laich E, Windhager R, Erwa W, Trajanoski S, Strom TM, Auer-Grumbach M. Whole-exome sequencing in patients with inherited neuropathies: outcome and challenges. J Neurol 2014; 261:970-82. [PMID: 24627108 DOI: 10.1007/s00415-014-7289-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 02/12/2014] [Accepted: 02/14/2014] [Indexed: 01/20/2023]
Abstract
Inherited peripheral neuropathies (IPN) are one of the most frequent inherited causes of neurological disability characterized by considerable phenotypic and genetic heterogeneity. Based on clinical and electrophysiological properties, they can be subdivided into three main groups: HMSN, dHMN, and HSN. At present, more than 50 IPN genes have been identified. Still, many patients and families with IPN have not yet received a molecular genetic diagnosis because clinical genetic testing usually only covers a subset of IPN genes. Moreover, a considerable proportion of IPN genes has to be identified. Here we present results of WES in 27 IPN patients excluded for mutations in many known IPN genes. Eight of the patients received a definite diagnosis. While six of these patients carried bona fide pathogenic mutations in known IPN genes, two patients had mutations in genes known to be involved in other types of neuromuscular disorders. A further group of eight patients carried sequence variations in IPN genes that could not unequivocally be classified as pathogenic. In addition, combining data of WES and linkage analysis identified SH3BP4, ITPR3, and KLHL13 as novel IPN candidate genes. Moreover, there was evidence that particular mutations in PEX12, a gene known to cause Zellweger syndrome, could also lead to an IPN phenotype. We show that WES is a useful tool for diagnosing IPN and we suggest an expanded phenotypic spectrum of some genes involved in other neuromuscular and neurodegenerative disorders. Nevertheless, interpretation of variants in known and potential novel disease genes has remained challenging.
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Affiliation(s)
- Maria Schabhüttl
- Department of Orthopaedics, Medical University Vienna, Währingergürtel 18-20, 1090, Vienna, Austria
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12
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Indo Y. Nerve growth factor, pain, itch and inflammation: lessons from congenital insensitivity to pain with anhidrosis. Expert Rev Neurother 2014; 10:1707-24. [DOI: 10.1586/ern.10.154] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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13
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Shorer Z, Wajsbrot E, Liran TH, Levy J, Parvari R. A novel mutation in SCN9A in a child with congenital insensitivity to pain. Pediatr Neurol 2014; 50:73-6. [PMID: 24188911 DOI: 10.1016/j.pediatrneurol.2013.09.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2013] [Revised: 09/03/2013] [Accepted: 09/09/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND [corrected] Congenital insensitivity to pain (CIP) is a rare condition in which patients have no pain perception and anosmia but are otherwise essentially normal (OMIM 243000). The recent discovery of the genetic defects underlying 3 monogenic pain disorders has provided additional and important insights about some components of human pain. Genetic studies in families demonstrating recessively inherited channelopathy-associated insensitivity to pain have identified nonsense mutations that result in truncation of the voltage-gated sodium channel type IX subunit (SCN9A), a 113.5-kb gene comprising coding 26 exons. Here we describe a patient with CIP with a new mutation in SCN9A not described yet. METHODS All exons were sequenced. RESULT All 26 coding exons were sequenced and two changes were identified in homozygosity in exon 10: c.1126 A > C causing K376Q and c.1124delG causing p.G375Afs* frame shift. CONCLUSION We report a novel, loss-of-function mutation in homozygosity that causes congenital insensitivity to pain and provide a comprehensive clinical description of the patient. This contributes to the clinical and neurophysiological characteristic of the sodium channel Nav1.7 channelopathy and expand our genetic knowledge which might provide more accurate and comprehensive clinical electrophysiological and genetic information.
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Affiliation(s)
- Zamir Shorer
- Department of Pediatrics, Soroka Medical Center, Beer Sheva, Israel; Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel.
| | - Einav Wajsbrot
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel; National Institute of Biotechnology, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Tamir-Hostovsky Liran
- Department of Pediatrics, Edmond & Lily Safra Children's Hospital, Sheba medical Center, Tel-Aviv, Israel
| | - Jacov Levy
- Department of Pediatrics, Soroka Medical Center, Beer Sheva, Israel; Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Ruti Parvari
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel; National Institute of Biotechnology, Ben Gurion University of the Negev, Beer Sheva, Israel
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14
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Abstract
Retrograde trophic signaling of nerve growth factor (NGF) supports neuronal survival and differentiation. Dysregulated trophic signaling could lead to various neurological disorders. Charcot-Marie-Tooth type 2B (CMT2B) is one of the most common inherited peripheral neuropathies characterized by severe terminal axonal loss. Genetic analysis of human CMT2B patients has revealed four missense point mutations in Rab7, a small GTPase that regulates late endosomal/lysosomal pathways, but the exact pathological mechanism remains poorly understood. Here, we show that these Rab7 mutants dysregulated axonal transport and diminished the retrograde signaling of NGF and its TrkA receptor. We found that all CMT2B Rab7 mutants were transported significantly faster than Rab7(wt) in the anterograde direction, accompanied with an increased percentile of anterograde Rab7-vesicles within axons of rat E15.5 dorsal root ganglion (DRG) neurons. In PC12M cells, the CMT2B Rab7 mutants drastically reduced the level of surface TrkA and NGF binding, presumably by premature degradation of TrkA. On the other hand, siRNA knock-down of endogenous Rab7 led to the appearance of large TrkA puncta in enlarged Rab5-early endosomes within the cytoplasm, suggesting delayed TrkA degradation. We also show that CMT2B Rab7 mutants markedly impaired NGF-induced Erk1/2 activation and differentiation in PC12M cells. Further analysis revealed that CMT2B Rab7 mutants caused axonal degeneration in rat E15.5 DRG neurons. We propose that Rab7 mutants induce premature degradation of retrograde NGF-TrkA trophic signaling, which may potentially contribute to the CMT2B disease.
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Abstract
Genetic disorders affecting the autonomic nervous system can result in abnormal development of the nervous system or they can be caused by neurotransmitter imbalance, an ion-channel disturbance or by storage of deleterious material. The symptoms indicating autonomic dysfunction, however, will depend upon whether the genetic lesion has disrupted peripheral or central autonomic centers or both. Because the autonomic nervous system is pervasive and affects every organ system in the body, autonomic dysfunction will result in impaired homeostasis and symptoms will vary. The possibility of genetic confirmation by molecular testing for specific diagnosis is increasing but treatments tend to remain only supportive and directed toward particular symptoms.
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Bercier V, Brustein E, Liao M, Dion PA, Lafrenière RG, Rouleau GA, Drapeau P. WNK1/HSN2 mutation in human peripheral neuropathy deregulates KCC2 expression and posterior lateral line development in zebrafish (Danio rerio). PLoS Genet 2013; 9:e1003124. [PMID: 23300475 PMCID: PMC3536653 DOI: 10.1371/journal.pgen.1003124] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 10/13/2012] [Indexed: 12/05/2022] Open
Abstract
Hereditary sensory and autonomic neuropathy type 2 (HSNAII) is a rare pathology characterized by an early onset of severe sensory loss (all modalities) in the distal limbs. It is due to autosomal recessive mutations confined to exon "HSN2" of the WNK1 (with-no-lysine protein kinase 1) serine-threonine kinase. While this kinase is well studied in the kidneys, little is known about its role in the nervous system. We hypothesized that the truncating mutations present in the neural-specific HSN2 exon lead to a loss-of-function of the WNK1 kinase, impairing development of the peripheral sensory system. To investigate the mechanisms by which the loss of WNK1/HSN2 isoform function causes HSANII, we used the embryonic zebrafish model and observed strong expression of WNK1/HSN2 in neuromasts of the peripheral lateral line (PLL) system by immunohistochemistry. Knocking down wnk1/hsn2 in embryos using antisense morpholino oligonucleotides led to improper PLL development. We then investigated the reported interaction between the WNK1 kinase and neuronal potassium chloride cotransporter KCC2, as this transporter is a target of WNK1 phosphorylation. In situ hybridization revealed kcc2 expression in mature neuromasts of the PLL and semi-quantitative RT-PCR of wnk1/hsn2 knockdown embryos showed an increased expression of kcc2 mRNA. Furthermore, overexpression of human KCC2 mRNA in embryos replicated the wnk1/hsn2 knockdown phenotype. We validated these results by obtaining double knockdown embryos, both for wnk1/hsn2 and kcc2, which alleviated the PLL defects. Interestingly, overexpression of inactive mutant KCC2-C568A, which does not extrude ions, allowed a phenocopy of the PLL defects. These results suggest a pathway in which WNK1/HSN2 interacts with KCC2, producing a novel regulation of its transcription independent of KCC2's activation, where a loss-of-function mutation in WNK1 induces an overexpression of KCC2 and hinders proper peripheral sensory nerve development, a hallmark of HSANII.
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Affiliation(s)
- Valérie Bercier
- Department of Pathology and Cell Biology, Université de Montréal, Montréal, Québec, Canada
- Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada
- Centre of Excellence in Neuroscience, Centre Hospitalier de l'Université de Montréal Research Center, Montréal, Québec, Canada
| | - Edna Brustein
- Department of Pathology and Cell Biology, Université de Montréal, Montréal, Québec, Canada
- Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada
| | - Meijiang Liao
- Department of Pathology and Cell Biology, Université de Montréal, Montréal, Québec, Canada
- Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada
| | - Patrick A. Dion
- Department of Pathology and Cell Biology, Université de Montréal, Montréal, Québec, Canada
- Centre of Excellence in Neuroscience, Centre Hospitalier de l'Université de Montréal Research Center, Montréal, Québec, Canada
| | - Ronald G. Lafrenière
- Centre of Excellence in Neuroscience, Centre Hospitalier de l'Université de Montréal Research Center, Montréal, Québec, Canada
| | - Guy A. Rouleau
- Centre of Excellence in Neuroscience, Centre Hospitalier de l'Université de Montréal Research Center, Montréal, Québec, Canada
- Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Pierre Drapeau
- Department of Pathology and Cell Biology, Université de Montréal, Montréal, Québec, Canada
- Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada
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17
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Abstract
Hereditary neuropathies (HN) with onset in childhood are categorized according to clinical presentation, pathogenic mechanism based on electrophysiology, genetic transmission and, in selected cases, pathological findings. Especially relevant to pediatrics are the items "secondary" versus "primary" neuropathy, "syndromic versus nonsyndromic," and "period of life." Different combinations of these parameters frequently point toward specific monogenic disorders. Ruling out a neuropathy secondary to a generalized metabolic disorder remains the first concern in pediatrics. As a rule, metabolic diseases include additional, orienting symptoms or signs, and their biochemical diagnosis is based on logical algorithms. Primary, motor sensory are the most frequent HN and are dominated by demyelinating autosomal dominant (AD) forms (CMT1). Other forms include demyelinating autosomal recessive (AR) forms, axonal AD/AR forms, and forms with "intermediate" electrophysiological phenotype. Peripheral motor neuron disorders are dominated by AR SMN-linked spinal muscular atrophies. (Distal) hereditary motor neuropathies represent <10% of HN but exhibit large clinical and genetic heterogeneity. Sensory/dysautonomic HN involves five classic subtypes, each one related to specific genes. However, genetic heterogeneity is larger than initially suspected. Syndromic HN distinguish "purely neurological syndromes", which are multisystemic, such as spinocerebellar atrophies +, spastic paraplegias +, etc. Peripheral neuropathy is possibly the presenting feature, including in childhood. Autosomal recessive forms, on average, start more frequently in childhood. "Multiorgan syndromes", on the other hand, are more specific to Pediatrics. AR forms, which are clearly degenerative, prompt the investigation of a large set of pleiotropic genes. Other syndromes expressed in the perinatal period are mainly developmental disorders, and can sometimes be related to specific transcription factors. Systematic malformative workup and ethical considerations are necessary. Altogether, >40 genes with various biological functions have been found to be responsible for primary HN. Many are responsible for various phenotypes, including some without the polyneuropathic trait, and some for various types of transmission.
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Affiliation(s)
- Pierre Landrieu
- Department of Pediatric Neurology, CHU Paris sud, Hôpital Bicêtre, Paris, France.
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18
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Abstract
Hereditary sensory and autonomic neuropathies (HSN/HSAN) are clinically and genetically heterogeneous disorders of the peripheral nervous system that predominantly affect the sensory and autonomic neurons. Hallmark features comprise not only prominent sensory signs and symptoms and ulcerative mutilations but also variable autonomic and motor disturbances. Autosomal dominant and autosomal recessive inheritance has been reported. Molecular genetics studies have identified disease-causing mutations in 11 genes. Some of the affected proteins have nerve-specific roles but underlying mechanisms have also been shown to involve sphingolipid metabolism, vesicular transport, structural integrity, and transcription regulation. Genetic and functional studies have substantially improved the understanding of the pathogenesis of the HSN/HSAN and will help to find preventive and causative therapies in the future.
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Landrieu P, Baets J, De Jonghe P. Hereditary motor-sensory, motor, and sensory neuropathies in childhood. HANDBOOK OF CLINICAL NEUROLOGY 2013; 113:1413-32. [PMID: 23622364 DOI: 10.1016/b978-0-444-59565-2.00011-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hereditary neuropathies (HN) are categorized according to clinical presentation, pathogenic mechanism based on electrophysiology, genetic transmission, age of occurrence, and, in selected cases, pathological findings. The combination of these parameters frequently orients towards specific genetic disorders. Ruling out a neuropathy secondary to a generalized metabolic disorder remains the first pediatric concern. Primary, motor-sensory are the most frequent HN and are dominated by demyelinating AD forms (CMT1). Others are demyelinating AR forms, axonal AD/AR forms, and forms with "intermediate" electrophysiological phenotype. Pure motor HN represent<10% of HN but exhibit large clinical and genetic heterogeneity. Sensory/dysautonomic HN cover five classical subtypes, each one related to specific genes. However, genetic heterogeneity is largly greater than initially suspected. Syndromic HN distinguish: "purely neurological syndromes", which are multisystemic, usually AD disorders, such as spinocerebellar atrophies +, spastic paraplegias +, etc. Peripheral Neuropathy may be the presenting feature, including in childhood. Clearly degenerative, AR forms prompt to investigate a large set of pleiotropic genes. Other syndromes, expressed in the perinatal period and comprising malformative features, are mainly developmental disorders, sometimes related to specific transcription factors. Altogether, >40 genes with various biological functions have been found responsible for HN. Many are responsible for various phenotypes, including some without the polyneuropathic trait: for the pediatric neurologist, phenotype/genotype correlations constitute a permanent bidirectional exercise.
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Affiliation(s)
- Pierre Landrieu
- Department of Paediatric Neurology, Université Paris Sud, Bicêtre Hospital, Paris, France.
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20
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Guernsey DL, Jiang H, Bedard K, Evans SC, Ferguson M, Matsuoka M, Macgillivray C, Nightingale M, Perry S, Rideout AL, Orr A, Ludman M, Skidmore DL, Benstead T, Samuels ME. Mutation in the gene encoding ubiquitin ligase LRSAM1 in patients with Charcot-Marie-Tooth disease. PLoS Genet 2010; 6. [PMID: 20865121 PMCID: PMC2928813 DOI: 10.1371/journal.pgen.1001081] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Accepted: 07/22/2010] [Indexed: 01/30/2023] Open
Abstract
Charcot-Marie-Tooth disease (CMT) represents a family of related sensorimotor neuropathies. We studied a large family from a rural eastern Canadian community, with multiple individuals suffering from a condition clinically most similar to autosomal recessive axonal CMT, or AR-CMT2. Homozygosity mapping with high-density SNP genotyping of six affected individuals from the family excluded 23 known genes for various subtypes of CMT and instead identified a single homozygous region on chromosome 9, at 122,423,730–129,841,977 Mbp, shared identical by state in all six affected individuals. A homozygous pathogenic variant was identified in the gene encoding leucine rich repeat and sterile alpha motif 1 (LRSAM1) by direct DNA sequencing of genes within the region in affected DNA samples. The single nucleotide change mutates an intronic consensus acceptor splicing site from AG to AA. Direct analysis of RNA from patient blood demonstrated aberrant splicing of the affected exon, causing an obligatory frameshift and premature truncation of the protein. Western blotting of immortalized cells from a homozygous patient showed complete absence of detectable protein, consistent with the splice site defect. LRSAM1 plays a role in membrane vesicle fusion during viral maturation and for proper adhesion of neuronal cells in culture. Other ubiquitin ligases play documented roles in neurodegenerative diseases. LRSAM1 is a strong candidate for the causal gene for the genetic disorder in our kindred. Sensory motor neuropathies are diseases of the peripheral nervous system, involving primarily the nerves which control our muscles. These can result from either genetic or non-genetic causes, with genetic causes usually referred to as Charcot-Marie-Tooth (CMT) disease after the three clinicians who first described the key diagnostic markers. CMT patients lose muscle function, mainly in their arms and legs, with increasing severity during their lives. There are almost two dozen known genes that can mutate to cause CMT, and these fall into a wide variety of biochemical cellular pathways. We identified a group of patients with CMT from a small rural community, with good reason to suspect a genetic basis for their disease. Using high-throughput mapping and DNA sequencing technologies developed as part of the Human Genome Project, we were able to find the likely mutated gene, which was not any of the previously known CMT genes. Based on its sequence, the gene, called LRSAM1, probably plays a role in the correct metabolism of other proteins in the cell. Among the known CMT genes, some are also involved in protein metabolism, suggesting that this is a generally important pathway in the neurons that control muscle activity.
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Affiliation(s)
- Duane L. Guernsey
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Haiyan Jiang
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Karen Bedard
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Susan C. Evans
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Meghan Ferguson
- Maritime Medical Genetics Service, Izaak Walton Killam Health Centre, Halifax, Nova Scotia, Canada
| | - Makoto Matsuoka
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Christine Macgillivray
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Mathew Nightingale
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Scott Perry
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Andrea L. Rideout
- Maritime Medical Genetics Service, Izaak Walton Killam Health Centre, Halifax, Nova Scotia, Canada
| | - Andrew Orr
- Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Mark Ludman
- Maritime Medical Genetics Service, Izaak Walton Killam Health Centre, Halifax, Nova Scotia, Canada
- Department of Pediatrics, Division of Medical Genetics, Izaak Walton Killam Health Centre and Dalhousie University, Halifax, Nova Scotia, Canada
| | - David L. Skidmore
- Maritime Medical Genetics Service, Izaak Walton Killam Health Centre, Halifax, Nova Scotia, Canada
- Department of Pediatrics, Division of Medical Genetics, Izaak Walton Killam Health Centre and Dalhousie University, Halifax, Nova Scotia, Canada
| | - Timothy Benstead
- Department of Medicine, Division of Neurology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Mark E. Samuels
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
- Centre de Recherche de l'Hôpital Ste-Justine, Université de Montréal, Montréal, Quebec, Canada
- * E-mail:
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21
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Penno A, Reilly MM, Houlden H, Laurá M, Rentsch K, Niederkofler V, Stoeckli ET, Nicholson G, Eichler F, Brown RH, von Eckardstein A, Hornemann T. Hereditary sensory neuropathy type 1 is caused by the accumulation of two neurotoxic sphingolipids. J Biol Chem 2010; 285:11178-87. [PMID: 20097765 DOI: 10.1074/jbc.m109.092973] [Citation(s) in RCA: 263] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
HSAN1 is an inherited neuropathy found to be associated with several missense mutations in the SPTLC1 subunit of serine palmitoyltransferase (SPT). SPT catalyzes the condensation of serine and palmitoyl-CoA, the initial step in the de novo synthesis of sphingolipids. Here we show that the HSAN1 mutations induce a shift in the substrate specificity of SPT, which leads to the formation of the two atypical deoxy-sphingoid bases (DSBs) 1-deoxy-sphinganine and 1-deoxymethyl-sphinganine. Both metabolites lack the C(1) hydroxyl group of sphinganine and can therefore neither be converted to complex sphingolipids nor degraded. Consequently, they accumulate in the cell, as demonstrated in HEK293 cells overexpressing mutant SPTLC1 and lymphoblasts of HSAN1 patients. Elevated DSB levels were also found in the plasma of HSAN1 patients and confirmed in three groups of HSAN1 patients with different SPTLC1 mutations. The DSBs show pronounced neurotoxic effects on neurite formation in cultured sensory neurons. The neurotoxicity co-occurs with a disturbed neurofilament structure in neurites when cultured in the presence of DSBs. Based on these observations, we conclude that HSAN1 is caused by a gain of function mutation, which results in the formation of two atypical and neurotoxic sphingolipid metabolites.
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Affiliation(s)
- Anke Penno
- Institute for Clinical Chemistry, University Hospital Zurich, Raemistrasse 100, CH-8091 Zurich, Switzerland
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22
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Abstract
The CMT2B (Charcot-Marie-Tooth type 2B) disease is an autosomal dominant axonal neuropathy. Sensory loss, distal muscle weakness and wasting, frequent foot ulcers and amputations of the toes due to frequent infections characterize this neuropathy. Four missense mutations in the rab7 gene have been identified as causative of the disease. Rab7 is a small G-protein of the Rab family that controls vesicular transport to late endosomes and lysosomes in the endocytic pathway. The CMT2B-associated mutant Rab7 proteins show altered nucleotide dissociation rates and impaired GTPase activity. In addition, these mutant proteins are predominantly in the GTP-bound form when expressed in human cells and they are able to rescue Rab7 function in Rab7-depleted cells. Thus these mutations generate activated forms of Rab7 that are responsible for the development of the disease. In spite of these results, there are still important gaps in our understanding of the mechanism underlying CMT2B. Indeed, how these mutations in the rab7 gene affect specifically peripheral neurons leading to an axonal pathology in CMT2B is not clear, and it is a particularly puzzling and challenging issue in view of the fact that Rab7 is a ubiquitous protein. The present review discusses possible molecular mechanisms underlying CMT2B.
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Abstract
Diabetic peripheral neuropathy is the most common peripheral neuropathy in the developed world; however, not all patients with diabetes and peripheral nerve disease have a peripheral neuropathy caused by diabetes. Several (although not all) studies have drawn attention to the presence of other potential causes of a neuropathy in individuals with diabetes; 10% to 50% of individuals with diabetes may have an additional potential cause of a peripheral neuropathy and some may have more than one cause. Neurotoxic medications, alcohol abuse, vitamin B(12) deficiency, renal disease, chronic inflammatory demyelinating neuropathy, inherited neuropathy, and vasculitis are the most common additional potential causes of a peripheral neuropathy in these series. The most common disorders in the differential diagnosis of a generalized diabetic peripheral neuropathy are discussed in this article. Prospective studies to investigate the prevalence of other disorders that might be responsible for a peripheral neuropathy in individuals with diabetes are warranted.
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Affiliation(s)
- Roy Freeman
- Autonomic and Peripheral Nerve Laboratory, Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.
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Rotthier A, Baets J, De Vriendt E, Jacobs A, Auer-Grumbach M, Lévy N, Bonello-Palot N, Kilic SS, Weis J, Nascimento A, Swinkels M, Kruyt MC, Jordanova A, De Jonghe P, Timmerman V. Genes for hereditary sensory and autonomic neuropathies: a genotype-phenotype correlation. Brain 2009; 132:2699-711. [PMID: 19651702 PMCID: PMC2759337 DOI: 10.1093/brain/awp198] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Hereditary sensory and autonomic neuropathies (HSAN) are clinically and genetically heterogeneous disorders characterized by axonal atrophy and degeneration, exclusively or predominantly affecting the sensory and autonomic neurons. So far, disease-associated mutations have been identified in seven genes: two genes for autosomal dominant (SPTLC1 and RAB7) and five genes for autosomal recessive forms of HSAN (WNK1/HSN2, NTRK1, NGFB, CCT5 and IKBKAP). We performed a systematic mutation screening of the coding sequences of six of these genes on a cohort of 100 familial and isolated patients diagnosed with HSAN. In addition, we screened the functional candidate gene NGFR (p75/NTR) encoding the nerve growth factor receptor. We identified disease-causing mutations in SPTLC1, RAB7, WNK1/HSN2 and NTRK1 in 19 patients, of which three mutations have not previously been reported. The phenotypes associated with mutations in NTRK1 and WNK1/HSN2 typically consisted of congenital insensitivity to pain and anhidrosis, and early-onset ulcero-mutilating sensory neuropathy, respectively. RAB7 mutations were only found in patients with a Charcot-Marie-Tooth type 2B (CMT2B) phenotype, an axonal sensory-motor neuropathy with pronounced ulcero-mutilations. In SPTLC1, we detected a novel mutation (S331F) corresponding to a previously unknown severe and early-onset HSAN phenotype. No mutations were found in NGFB, CCT5 and NGFR. Overall disease-associated mutations were found in 19% of the studied patient group, suggesting that additional genes are associated with HSAN. Our genotype–phenotype correlation study broadens the spectrum of HSAN and provides additional insights for molecular and clinical diagnosis.
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Affiliation(s)
- Annelies Rotthier
- Peripheral Neuropathy Group, VIB-Department of Molecular Genetics, University of Antwerp, Universiteitsplein 1, Antwerpen, Belgium
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25
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Nilsen KB, Nicholas AK, Woods CG, Mellgren SI, Nebuchennykh M, Aasly J. Two novel SCN9A mutations causing insensitivity to pain. Pain 2009; 143:155-8. [DOI: 10.1016/j.pain.2009.02.016] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2008] [Revised: 02/18/2009] [Accepted: 02/19/2009] [Indexed: 10/21/2022]
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Carriers of recessive WNK1/HSN2 mutations for hereditary sensory and autonomic neuropathy type 2 (HSAN2) are more sensitive to thermal stimuli. J Neurosci 2009; 29:2162-6. [PMID: 19228968 DOI: 10.1523/jneurosci.4633-08.2009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Hereditary sensory and autonomic neuropathy type 2 (HSAN2) is a rare recessive genetic disorder characterized by severe sensory loss affecting the tactile, thermal and nociceptive modalities. Although heterozygous carriers of nonsense mutations in the HSN2 gene, called with-no-lysine(K)-1 (WNK1), do not develop the disease, historical and experimental evidence suggests that these individuals might perceive somatosensory stimuli differently from others. Using the method-of-limits, we assessed the thresholds for warmth detection, cool detection, heat pain and cold pain in 25 mutation carriers and 35 controls. In group analyses, carriers displayed significantly lower warmth (p<0.001) and cool (p<0.05) difference thresholds, and also tended to report cold pain at higher temperatures (p=0.095), than controls. Similarly, matched-pair analyses showed that carriers are significantly more sensitive to warm stimuli (p<0.01) and cold pain stimuli (p<0.05), and tend to be more sensitive to cool stimuli (p=0.11). Furthermore, the differences between the warmth detection thresholds of the carriers and those of gender- and sex-matched wild types significantly increased with age (r=0.76, p=0.02), and in carriers cool detection thresholds did not increase with age (r=0.27, p=0.24) as expected and observed in controls (r=0.34, p=0.05). This study demonstrates that the carriers of a recessive mutation for HSAN2 display greater sensitivity to innocuous thermal stimuli, as well as for cold pain, suggesting a possible environmental adaptive advantage of the heterozygous state.
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De Luca A, Progida C, Spinosa MR, Alifano P, Bucci C. Characterization of the Rab7K157N mutant protein associated with Charcot-Marie-Tooth type 2B. Biochem Biophys Res Commun 2008; 372:283-7. [PMID: 18501189 DOI: 10.1016/j.bbrc.2008.05.060] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Accepted: 05/14/2008] [Indexed: 10/22/2022]
Abstract
Four missense mutations, that target highly conserved amino acid residues in the small GTPase Rab7, have been associated with the Charcot-Marie-Tooth (CMT) type 2B phenotype. CMT2B peripheral axonal neuropathies are characterized by severe sensory loss, often complicated by infections, arthropathy, and amputations. Here, we have investigated the biochemical and functional properties of the Rab7 K157N mutated protein. Interestingly, Rab7 K157N showed altered nucleotide exchange rate and GTP hydrolysis compared to the wild type protein. Consistently, the majority of the expressed protein in HeLa cells was bound to GTP. In addition, Rab7 K157N was able to restore EGF degradation, previously inhibited by Rab7 silencing. Altogether these data indicate that Rab7 K157N, similarly to the other three mutated proteins causative of CMT2B, is predominantly in the GTP-bound form and behaves as an active mutant. Therefore, activated forms of Rab7 protein cause the CMT2B disease.
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Affiliation(s)
- Azzurra De Luca
- Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali (DiSTeBA), Università del Salento, Via Provinciale Monteroni, 73100 Lecce, Italy
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28
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Functional characterization of Rab7 mutant proteins associated with Charcot-Marie-Tooth type 2B disease. J Neurosci 2008; 28:1640-8. [PMID: 18272684 DOI: 10.1523/jneurosci.3677-07.2008] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Charcot-Marie-Tooth (CMT) type 2 neuropathies are a group of autosomal-dominant axonal disorders genetically and clinically heterogeneous. In particular, CMT type 2B (CMT2B) neuropathies are characterized by severe sensory loss, often complicated by infections, arthropathy, and amputations. Recently, four missense mutations in the small GTPase Rab7 associated with the Charcot-Marie Tooth type 2B phenotype have been identified. These mutations target highly conserved amino acid residues. However, nothing is known about whether and how these mutations affect Rab7 function. We investigated the biochemical and functional properties of three of the mutant proteins. Interestingly, all three proteins exhibited higher nucleotide exchange rates and hydrolyzed GTP slower than the wild-type protein. In addition, whereas 23% of overexpressed wild-type Rab7 was GTP bound in HeLa cells, the large majority of the mutant proteins (82-89%) were in the GTP-bound form, consistent with the data on GTP hydrolysis and exchange rates. The CMT2B-associated Rab7 proteins were also able to bind the Rab7 effector RILP (Rab-interacting lysosomal protein) and to rescue Rab7 function after silencing. Altogether, these data demonstrate that all tested CMT2B-associated Rab7 mutations are mechanistically similar, suggesting that activated forms of the Rab7 are responsible for CMT2B disease.
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29
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Barisic N, Claeys KG, Sirotković-Skerlev M, Löfgren A, Nelis E, De Jonghe P, Timmerman V. Charcot-Marie-Tooth disease: a clinico-genetic confrontation. Ann Hum Genet 2008; 72:416-41. [PMID: 18215208 DOI: 10.1111/j.1469-1809.2007.00412.x] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Charcot-Marie-Tooth disease (CMT) is the most common neuromuscular disorder. It represents a group of clinically and genetically heterogeneous inherited neuropathies. Here, we review the results of molecular genetic investigations and the clinical and neurophysiological features of the different CMT subtypes. The products of genes associated with CMT phenotypes are important for the neuronal structure maintenance, axonal transport, nerve signal transduction and functions related to the cellular integrity. Identifying the molecular basis of CMT and studying the relevant genes and their functions is important to understand the pathophysiological mechanisms of these neurodegenerative disorders, and the processes involved in the normal development and function of the peripheral nervous system. The results of molecular genetic investigations have impact on the appropriate diagnosis, genetic counselling and possible new therapeutic options for CMT patients.
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Affiliation(s)
- N Barisic
- Department of Pediatrics, Zagreb University Medical School, Zagreb, Croatia.
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30
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Planté-Bordeneuve V. Introduzione agli aspetti genetici delle neuropatie. Neurologia 2008. [DOI: 10.1016/s1634-7072(08)70524-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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