1
|
Ma X, Liu X, Duan X, Fan D. Screening for PRX mutations in a large Chinese Charcot-Marie-Tooth disease cohort and literature review. Front Neurol 2023; 14:1148044. [PMID: 37470010 PMCID: PMC10352492 DOI: 10.3389/fneur.2023.1148044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 06/06/2023] [Indexed: 07/21/2023] Open
Abstract
Background Periaxins (encoded by PRX) play an important role in the stabilization of peripheral nerve myelin. Mutations in PRX can lead to Charcot-Marie-Tooth disease type 4F (CMT4F). Methods In this study, we screened for PRX mutations using next-generation sequencing and whole-exome sequencing in a large Chinese CMT cohort consisting of 465 unrelated index patients and 650 healthy controls. Sanger sequencing was used for the validation of all identified variants. We also reviewed all previously reported PRX-related CMT cases and summarized the clinical manifestations and genetic features of PRX-related CMTs. Results The hit rate for biallelic PRX variants in our cohort of Chinese CMT patients was 0.43% (2/465). One patient carried a previously unreported splice-site mutation (c.25_27 + 9del) compound heterozygous with a known nonsense variant. Compiling data on CMT4F cases and PRX variants from the medical literature confirmed that early-onset (95.2%), distal amyotrophy or weakness (94.0%), feet deformity (75.0%), sensory impairment or sensory ataxia (65.5%), delayed motor milestones (60.7%), and spinal deformity (59.5%) are typical features for CMT4F. Less frequent features were auditory impairments, respiratory symptoms, late onset, dysarthria or hoarseness, ophthalmic problems, and central nervous system involvement. The two cases with biallelic missense mutations have later onset age than those with nonsense or frameshift mutations. We did not note clear correlations between the type and site of mutations and clinical severity or distinct constellations of symptoms. Conclusion Consistent with observations in other countries and ethnic groups, PRX-related CMT is rare in China. The clinical spectrum is wider than previously anticipated.
Collapse
Affiliation(s)
- Xinran Ma
- Department of Neurology, Peking University Third Hospital, Beijing, China
- Key Laboratory for Neuroscience, National Health Commission/Ministry of Education, Peking University, Beijing, China
- Beijing Key Laboratory of Biomarker and Translational Research in Neurodegenerative Diseases, Beijing, China
| | - Xiaoxuan Liu
- Department of Neurology, Peking University Third Hospital, Beijing, China
- Key Laboratory for Neuroscience, National Health Commission/Ministry of Education, Peking University, Beijing, China
- Beijing Key Laboratory of Biomarker and Translational Research in Neurodegenerative Diseases, Beijing, China
| | - Xiaohui Duan
- Department of Neurology, China-Japan Friendship Hospital, Beijing, China
| | - Dongsheng Fan
- Department of Neurology, Peking University Third Hospital, Beijing, China
- Key Laboratory for Neuroscience, National Health Commission/Ministry of Education, Peking University, Beijing, China
- Beijing Key Laboratory of Biomarker and Translational Research in Neurodegenerative Diseases, Beijing, China
| |
Collapse
|
2
|
Krokengen OC, Raasakka A, Kursula P. The intrinsically disordered protein glue of the myelin major dense line: Linking AlphaFold2 predictions to experimental data. Biochem Biophys Rep 2023; 34:101474. [PMID: 37153862 PMCID: PMC10160357 DOI: 10.1016/j.bbrep.2023.101474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 03/31/2023] [Accepted: 04/19/2023] [Indexed: 05/10/2023] Open
Abstract
Numerous human proteins are classified as intrinsically disordered proteins (IDPs). Due to their physicochemical properties, high-resolution structural information about IDPs is generally lacking. On the other hand, IDPs are known to adopt local ordered structures upon interactions with e.g. other proteins or lipid membrane surfaces. While recent developments in protein structure prediction have been revolutionary, their impact on IDP research at high resolution remains limited. We took a specific example of two myelin-specific IDPs, the myelin basic protein (MBP) and the cytoplasmic domain of myelin protein zero (P0ct). Both of these IDPs are crucial for normal nervous system development and function, and while they are disordered in solution, upon membrane binding, they partially fold into helices, being embedded into the lipid membrane. We carried out AlphaFold2 predictions of both proteins and analysed the models in light of experimental data related to protein structure and molecular interactions. We observe that the predicted models have helical segments that closely correspond to the membrane-binding sites on both proteins. We furthermore analyse the fits of the models to synchrotron-based X-ray scattering and circular dichroism data from the same IDPs. The models are likely to represent the membrane-bound state of both MBP and P0ct, rather than the conformation in solution. Artificial intelligence-based models of IDPs appear to provide information on the ligand-bound state of these proteins, instead of the conformers dominating free in solution. We further discuss the implications of the predictions for mammalian nervous system myelination and their relevance to understanding disease aspects of these IDPs.
Collapse
Affiliation(s)
| | - Arne Raasakka
- Department of Biomedicine, University of Bergen, Norway
| | - Petri Kursula
- Department of Biomedicine, University of Bergen, Norway
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, Oulu, Finland
- Corresponding author. Department of Biomedicine, University of Bergen, Norway.
| |
Collapse
|
3
|
Ferrara JM, Wiid M, Burke S. Contactin-Associated Protein-Like 2-Related Peripheral Nerve Hyperexcitability Associated With Charcot-Marie-Tooth Type 4F. Neurohospitalist 2023; 13:164-168. [PMID: 37064943 PMCID: PMC10091429 DOI: 10.1177/19418744221140182] [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: 02/17/2023] Open
Abstract
Contactin-associated protein-like 2 autoimmunity is an uncommon disorder resulting in peripheral nerve hyperexcitability or encephalitis. In a fifth of cases, onset may be provoked by thymoma, but other associations are largely unknown. We report a patient with anti-contactin-associated protein-like 2-related peripheral nerve hyperexcitability arising in the setting of Charcot-Marie-Tooth type 4F and discuss potential mechanisms underlying the association.
Collapse
Affiliation(s)
- Joseph M. Ferrara
- Division of Neurology, Department of
Internal Medicine, East Carolina University School of
Medicine, Greenville, NC, USA
- Department of Internal Medicine, Virginia Tech Carilion, Roanoke, VA, USA
| | - Michael Wiid
- Department of Internal Medicine, Virginia Tech Carilion, Roanoke, VA, USA
| | - Sean Burke
- Department of Internal Medicine, Virginia Tech Carilion, Roanoke, VA, USA
- Comprehensive Neurology Services, Frederick Health, Frederick, MD, USA
| |
Collapse
|
4
|
Novel Variants in MPV17, PRX, GJB1, and SACS Cause Charcot-Marie-Tooth and Spastic Ataxia of Charlevoix-Saguenay Type Diseases. Genes (Basel) 2023; 14:genes14020328. [PMID: 36833258 PMCID: PMC9956329 DOI: 10.3390/genes14020328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/22/2023] [Accepted: 01/25/2023] [Indexed: 01/31/2023] Open
Abstract
Charcot-Marie-Tooth disease (CMT) and autosomal recessive spastic ataxia of Charlevoix-Saguenay type (ARSACS) are large heterogeneous groups of sensory, neurological genetic disorders characterized by sensory neuropathies, muscular atrophies, abnormal sensory conduction velocities, and ataxia. CMT2EE (OMIM: 618400) is caused by mutations in MPV17 (OMIM: 137960), CMT4F (OMIM: 614895) is caused by PRX (OMIM: 605725), CMTX1 (OMIM: 302800) is caused by mutations in GJB1 (OMIM: 304040), and ARSACS (OMIM: 270550) is caused by mutations in SACS (OMIM: 604490). In this study, we enrolled four families: DG-01, BD-06, MR-01, and ICP-RD11, with 16 affected individuals, for clinical and molecular diagnoses. One patient from each family was analyzed for whole exome sequencing and Sanger sequencing was done for the rest of the family members. Affected individuals of families BD-06 and MR-01 show complete CMT phenotypes and family ICP-RD11 shows ARSACS type. Family DG-01 shows complete phenotypes for both CMT and ARSACS types. The affected individuals have walking difficulties, ataxia, distal limb weakness, axonal sensorimotor neuropathies, delayed motor development, pes cavus, and speech articulations with minor variations. The WES analysis in an indexed patient of family DG-01 identified two novel variants: c.83G>T (p.Gly28Val) in MPV17 and c.4934G>C (p.Arg1645Pro) in SACS. In family ICP-RD11, a recurrent mutation that causes ARSACS, c.262C>T (p.Arg88Ter) in SACS, was identified. Another novel variant, c.231C>A (p.Arg77Ter) in PRX, which causes CMT4F, was identified in family BD-06. In family MR-01, a hemizygous missense variant c.61G>C (p.Gly21Arg) in GJB1 was identified in the indexed patient. To the best of our knowledge, there are very few reports on MPV17, SACS, PRX, and GJB1 causing CMT and ARSACS phenotypes in the Pakistani population. Our study cohort suggests that whole exome sequencing can be a useful tool in diagnosing complex multigenic and phenotypically overlapping genetic disorders such as Charcot-Marie-Tooth disease (CMT) and spastic ataxia of Charlevoix-Saguenay type.
Collapse
|
5
|
Pathological evidence of demyelination in the recurrent laryngeal, phrenic, and oculomotor nerves in Charcot-Marie-Tooth disease 4F. eNeurologicalSci 2022; 25:100358. [PMID: 34993357 PMCID: PMC8713021 DOI: 10.1016/j.ensci.2021.100358] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 07/05/2021] [Accepted: 07/11/2021] [Indexed: 11/22/2022] Open
Abstract
We present pathology of the peripheral nerves of a patient with Adult-onset Charcot-Marie-Tooth disease 4F caused by periaxin gene mutation p.D651N. The patient was a 72-year-old woman. She had hoarseness and underwent continuous positive airway pressure therapy at night due to sleep apnea. The patient died abruptly. Remarkable demyelination with tomacula formation was found in the phrenic nerve, vagal nerve, recurrent laryngeal nerve, and oculomotor nerves. The cause of death could have been insufficient reactivity to the aspiration or sudden onset of bilateral vocal cord palsy. We must pay attention to respiratory function and cranial nerve palsies in hereditary demyelinating neuropathies.
Collapse
|
6
|
Shintaku M, Maeda K, Shiohara M, Namura T, Kushima R. Neuropathology of the spinal nerve roots, spinal cord, and brain in the first autopsied case of Charcot-Marie-Tooth disease 4F with a D651N mutation in the periaxin gene. Neuropathology 2021; 41:281-287. [PMID: 34002422 DOI: 10.1111/neup.12731] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/07/2021] [Accepted: 01/14/2021] [Indexed: 11/29/2022]
Abstract
Charcot-Marie-Tooth disease (CMT) 4F is an autosomal recessive, hereditary peripheral neuropathy, mostly caused by mutations in the periaxin gene (PRX). This article reports neuropathological findings of the spinal nerve roots, spinal cord, and brain of a patient with CMT4F and a D651N missense mutation in PRX. The patient was a 74-year-old woman who had a history of peripheral neuropathy with onset at the age of 30 years. She also had a history of infantile paralysis at the age of 18 months. The most pronounced autopsy finding was diffuse enlargement of anterior and posterior nerve roots, accentuated at the lumbo-sacral levels. On microscopy, the swollen nerve roots showed a loss of large-diameter myelinated fibers and formation of numerous onion bulbs. Most of the onion bulbs lacked the central, regenerating thin myelin sheaths, and in large-diameter nerve fibers whose axons had been lost, collagen fibers occupied the center of the onion bulbs. Some nerve roots formed glial bundles at the proximal end. The spinal cord showed degeneration of the gracile fascicles, and the lumbar segment anterior horn showed an asymmetric neuronal loss with rarefaction of the neuropil. The brain did not show any notable changes except for multiple foci of a radial microcolumnar arrangement of neurons in the cerebral cortex. Degeneration of the lumbar segment anterior horn is most likely secondary to the anterior radiculopathy, but a localized circulatory disturbance is another possibility.
Collapse
Affiliation(s)
| | - Kengo Maeda
- Department of Neurology, Vories Memorial Hospital, Omi-hachiman, Japan
| | - Masanori Shiohara
- Department of Clinical Laboratory Medicine and Diagnostic Pathology, Shiga University of Medical Science, Ohtsu, Japan
| | - Tomo Namura
- Department of Clinical Laboratory Medicine and Diagnostic Pathology, Shiga University of Medical Science, Ohtsu, Japan
| | - Ryoji Kushima
- Department of Clinical Laboratory Medicine and Diagnostic Pathology, Shiga University of Medical Science, Ohtsu, Japan
| |
Collapse
|
7
|
Siems SB, Jahn O, Eichel MA, Kannaiyan N, Wu LMN, Sherman DL, Kusch K, Hesse D, Jung RB, Fledrich R, Sereda MW, Rossner MJ, Brophy PJ, Werner HB. Proteome profile of peripheral myelin in healthy mice and in a neuropathy model. eLife 2020; 9:e51406. [PMID: 32130108 PMCID: PMC7056269 DOI: 10.7554/elife.51406] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 02/19/2020] [Indexed: 02/07/2023] Open
Abstract
Proteome and transcriptome analyses aim at comprehending the molecular profiles of the brain, its cell-types and subcellular compartments including myelin. Despite the relevance of the peripheral nervous system for normal sensory and motor capabilities, analogous approaches to peripheral nerves and peripheral myelin have fallen behind evolving technical standards. Here we assess the peripheral myelin proteome by gel-free, label-free mass-spectrometry for deep quantitative coverage. Integration with RNA-Sequencing-based developmental mRNA-abundance profiles and neuropathy disease genes illustrates the utility of this resource. Notably, the periaxin-deficient mouse model of the neuropathy Charcot-Marie-Tooth 4F displays a highly pathological myelin proteome profile, exemplified by the discovery of reduced levels of the monocarboxylate transporter MCT1/SLC16A1 as a novel facet of the neuropathology. This work provides the most comprehensive proteome resource thus far to approach development, function and pathology of peripheral myelin, and a straightforward, accurate and sensitive workflow to address myelin diversity in health and disease.
Collapse
Affiliation(s)
- Sophie B Siems
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
| | - Olaf Jahn
- Proteomics Group, Max Planck Institute of Experimental MedicineGöttingenGermany
| | - Maria A Eichel
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
| | - Nirmal Kannaiyan
- Department of Psychiatry and Psychotherapy, University Hospital, LMU MunichMunichGermany
| | - Lai Man N Wu
- Centre for Discovery Brain Sciences, University of EdinburghEdinburghUnited Kingdom
| | - Diane L Sherman
- Centre for Discovery Brain Sciences, University of EdinburghEdinburghUnited Kingdom
| | - Kathrin Kusch
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
| | - Dörte Hesse
- Proteomics Group, Max Planck Institute of Experimental MedicineGöttingenGermany
| | - Ramona B Jung
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
| | - Robert Fledrich
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
- Institute of Anatomy, University of LeipzigLeipzigGermany
| | - Michael W Sereda
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
- Department of Clinical Neurophysiology, University Medical CenterGöttingenGermany
| | - Moritz J Rossner
- Department of Psychiatry and Psychotherapy, University Hospital, LMU MunichMunichGermany
| | - Peter J Brophy
- Centre for Discovery Brain Sciences, University of EdinburghEdinburghUnited Kingdom
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
| |
Collapse
|
8
|
Raasakka A, Kursula P. Flexible Players within the Sheaths: The Intrinsically Disordered Proteins of Myelin in Health and Disease. Cells 2020; 9:cells9020470. [PMID: 32085570 PMCID: PMC7072810 DOI: 10.3390/cells9020470] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 02/16/2020] [Accepted: 02/16/2020] [Indexed: 02/07/2023] Open
Abstract
Myelin ensheathes selected axonal segments within the nervous system, resulting primarily in nerve impulse acceleration, as well as mechanical and trophic support for neurons. In the central and peripheral nervous systems, various proteins that contribute to the formation and stability of myelin are present, which also harbor pathophysiological roles in myelin disease. Many myelin proteins have common attributes, including small size, hydrophobic segments, multifunctionality, longevity, and regions of intrinsic disorder. With recent advances in protein biophysical characterization and bioinformatics, it has become evident that intrinsically disordered proteins (IDPs) are abundant in myelin, and their flexible nature enables multifunctionality. Here, we review known myelin IDPs, their conservation, molecular characteristics and functions, and their disease relevance, along with open questions and speculations. We place emphasis on classifying the molecular details of IDPs in myelin, and we correlate these with their various functions, including susceptibility to post-translational modifications, function in protein–protein and protein–membrane interactions, as well as their role as extended entropic chains. We discuss how myelin pathology can relate to IDPs and which molecular factors are potentially involved.
Collapse
Affiliation(s)
- Arne Raasakka
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, NO-5009 Bergen, Norway;
| | - Petri Kursula
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, NO-5009 Bergen, Norway;
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Aapistie 7A, FI-90220 Oulu, Finland
- Correspondence:
| |
Collapse
|
9
|
Chen YH, Zhang H, Meng LB, Tang XY, Gong T, Yin J. Novel mutation in the periaxin gene causal to Charcot-Marie-Tooth disease type 4F. J Int Med Res 2020; 48:300060519862064. [PMID: 31426691 PMCID: PMC7581982 DOI: 10.1177/0300060519862064] [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] [Indexed: 11/16/2022] Open
Abstract
Charcot–Marie–Tooth (CMT) disease is the most common hereditary neuropathy. Mutations in the periaxin gene (PRX) can cause CMT type 4F, an autosomal recessive neuropathy, which is clinically characterized by slowly progressive distal muscle atrophy and weakness, with pes cavus deformity of the foot, and the absence of deep tendon reflexes. To date, dozens of reports of PRX mutations have been published worldwide, but none have been reported in Chinese patients. Here, we describe a 14-year-old Chinese boy with neuropathy characterized by slowly progressive limb weakness and atrophy, as well as sensory ataxia, whose cerebrospinal protein levels were 1627 mg/L. Genetic analysis identified a novel homozygous mutation, c.1174C>T (p.R392X), in exon 6 of PRX, which is the first case of its kind recorded in China.
Collapse
Affiliation(s)
- Yu-Hui Chen
- Neurology Department, Beijing Hospital, National Center of Gerontology, Beijing 100730, P. R. China
| | - Hua Zhang
- Neurology Department, Beijing Hospital, National Center of Gerontology, Beijing 100730, P. R. China
| | - Ling-Bing Meng
- Neurology Department, Beijing Hospital, National Center of Gerontology, Beijing 100730, P. R. China
| | - Xiao-Yan Tang
- Clinical Laboratory of Zhongke, Beijing 102200, P. R. China
| | - Tao Gong
- Neurology Department, Beijing Hospital, National Center of Gerontology, Beijing 100730, P. R. China
| | - Jian Yin
- Neurology Department, Beijing Hospital, National Center of Gerontology, Beijing 100730, P. R. China
| |
Collapse
|
10
|
Datta S, Kataria S, Govindarajan R. A Case Report on Charcot-Marie-Tooth Disease with a Novel Periaxin Gene Mutation. Cureus 2019; 11:e5111. [PMID: 31523542 PMCID: PMC6741374 DOI: 10.7759/cureus.5111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Charcot-Marie-Tooth (CMT) disease is one of the most common primary hereditary neuropathies causing peripheral neuropathies. More than 60 different gene mutations are causing this disease. The PRX gene codes for Periaxin proteins that are expressed by Schwann cells and are necessary for the formation and maintenance of myelination of peripheral nerves. Dejerine-Sottas neuropathy and Charcot-Marie-Tooth type 4F (CMT4F) are the two different clinical phenotypes observed in association with PRX gene mutation. This article describes a case of an elderly male with a novel mutation involving the PRX gene.
Collapse
Affiliation(s)
- Sorabh Datta
- Neurology, University of Missouri, Columbia, USA
| | | | | |
Collapse
|
11
|
Raasakka A, Linxweiler H, Brophy PJ, Sherman DL, Kursula P. Direct Binding of the Flexible C-Terminal Segment of Periaxin to β4 Integrin Suggests a Molecular Basis for CMT4F. Front Mol Neurosci 2019; 12:84. [PMID: 31024253 PMCID: PMC6465933 DOI: 10.3389/fnmol.2019.00084] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 03/19/2019] [Indexed: 11/13/2022] Open
Abstract
The process of myelination in the nervous system requires a coordinated formation of both transient and stable supramolecular complexes. Myelin-specific proteins play key roles in these assemblies, which may link membranes to each other or connect the myelinating cell cytoskeleton to the extracellular matrix. The myelin protein periaxin is known to play an important role in linking the Schwann cell cytoskeleton to the basal lamina through membrane receptors, such as the dystroglycan complex. Mutations that truncate periaxin from the C terminus cause demyelinating peripheral neuropathy, Charcot-Marie-Tooth (CMT) disease type 4F, indicating a function for the periaxin C-terminal region in myelination. We identified the cytoplasmic domain of β4 integrin as a specific high-affinity binding partner for periaxin. The C-terminal region of periaxin remains unfolded and flexible when bound to the third fibronectin type III domain of β4 integrin. Our data suggest that periaxin is able to link the Schwann cell cytoplasm to the basal lamina through a two-pronged interaction via different membrane protein complexes, which bind close to the N and C terminus of this elongated, flexible molecule.
Collapse
Affiliation(s)
- Arne Raasakka
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | | | - Peter J. Brophy
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Diane L. Sherman
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Petri Kursula
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| |
Collapse
|
12
|
Guan M, Keaton JM, Dimitrov L, Hicks PJ, Xu J, Palmer ND, Wilson JG, Freedman BI, Bowden DW, Ng MC. An Exome-wide Association Study for Type 2 Diabetes-Attributed End-Stage Kidney Disease in African Americans. Kidney Int Rep 2018; 3:867-878. [PMID: 29989002 PMCID: PMC6035163 DOI: 10.1016/j.ekir.2018.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 02/20/2018] [Accepted: 03/05/2018] [Indexed: 12/12/2022] Open
Abstract
Introduction Compared with European Americans, African Americans (AAs) are at higher risk for developing end-stage kidney disease (ESKD). Genome-wide association studies (GWAS) have identified >70 genetic variants associated with kidney function and chronic kidney disease (CKD) in patients with and without diabetes. However, these variants explain a small proportion of disease liability. This study examined the contribution of coding genetic variants for risk of type 2 diabetes (T2D)-attributed ESKD and advanced CKD in AAs. Methods Exome sequencing was performed in 456 AA T2D-ESKD cases, and 936 AA nondiabetic, non-nephropathy control individuals at the discovery stage. A mixed logistic regression model was used for association analysis. Nominal associations (P < 0.05) were replicated in an additional 2020 T2D-ESKD cases and 1121 nondiabetic, non-nephropathy control individuals. A meta-analysis combining 4533 discovery and replication samples was performed. Putative T2D-ESKD associations were tested in additional 1910 nondiabetic ESKD and 219 T2D-ESKD cases, as well as 912 AA nondiabetic non-nephropathy control individuals. Results A total of 11 suggestive T2D-ESKD associations (P < 1 x 10−4) from 8 loci (PLEKHN1, NADK, RAD51AP2, RREB1, PEX6, GRM8, PRX, APOL1) were apparent in the meta-analysis. Exclusion of APOL1 renal-risk genotype carriers identified 3 additional suggestive loci (OTUD7B, IFITM3, DLGAP5). Rs41302867 in RREB1 displayed consistent association with T2D-ESKD and nondiabetic ESKD (odds ratio: 0.47; P = 1.2 x 10−6 in 4605 all-cause ESKD and 2969 nondiabetic non-nephropathy control individuals). Conclusion Our findings suggest that coding genetic variants are implicated in predisposition to T2D-ESKD in AAs.
Collapse
Affiliation(s)
- Meijian Guan
- Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
- Center for Diabetes Research, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Jacob M. Keaton
- Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
- Center for Diabetes Research, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Latchezar Dimitrov
- Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Pamela J. Hicks
- Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Jianzhao Xu
- Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Nicholette D. Palmer
- Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
- Center for Diabetes Research, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - James G. Wilson
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Barry I. Freedman
- Department of Internal Medicine, Section on Nephrology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Donald W. Bowden
- Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
- Center for Diabetes Research, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Maggie C.Y. Ng
- Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
- Center for Diabetes Research, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
- Correspondence: Maggie C. Y. Ng, Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA.
| |
Collapse
|
13
|
Sherman DL, Brophy PJ. A murine model of Charcot-Marie-Tooth disease 4F reveals a role for the C-terminus of periaxin in the formation and stabilization of Cajal bands. Wellcome Open Res 2018; 3:20. [PMID: 29623298 PMCID: PMC5861512 DOI: 10.12688/wellcomeopenres.13673.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/23/2018] [Indexed: 11/20/2022] Open
Abstract
Charcot-Marie-Tooth (CMT) disease comprises up to 80 monogenic inherited neuropathies of the peripheral nervous system (PNS) that collectively result in demyelination and axon degeneration. The majority of CMT disease is primarily either dysmyelinating or demyelinating in which mutations affect the ability of Schwann cells to either assemble or stabilize peripheral nerve myelin. CMT4F is a recessive demyelinating form of the disease caused by mutations in the
Periaxin (
PRX) gene
. Periaxin (Prx) interacts with Dystrophin Related Protein 2 (Drp2) in an adhesion complex with the laminin receptor Dystroglycan (Dag). In mice the Prx/Drp2/Dag complex assembles adhesive domains at the interface between the abaxonal surface of the myelin sheath and the cytoplasmic surface of the Schwann cell plasma membrane. Assembly of these appositions causes the formation of cytoplasmic channels called Cajal bands beneath the surface of the Schwann cell plasma membrane. Loss of either Periaxin or Drp2 disrupts the appositions and causes CMT in both mouse and man. In a mouse model of CMT4F, complete loss of Periaxin first prevents normal Schwann cell elongation resulting in abnormally short internodal distances which can reduce nerve conduction velocity, and subsequently precipitates demyelination. Distinct functional domains responsible for Periaxin homodimerization and interaction with Drp2 to form the Prx/Drp2/Dag complex have been identified at the N-terminus of Periaxin. However, CMT4F can also be caused by a mutation that results in the truncation of Periaxin at the extreme C-terminus with the loss of 391 amino acids. By modelling this in mice, we show that loss of the C-terminus of Periaxin results in a surprising reduction in Drp2. This would be predicted to cause the observed instability of both appositions and myelin, and contribute significantly to the clinical phenotype in CMT4F.
Collapse
Affiliation(s)
- Diane L Sherman
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - Peter J Brophy
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH16 4SB, UK
| |
Collapse
|
14
|
Higuchi Y, Hashiguchi A, Yuan J, Yoshimura A, Mitsui J, Ishiura H, Tanaka M, Ishihara S, Tanabe H, Nozuma S, Okamoto Y, Matsuura E, Ohkubo R, Inamizu S, Shiraishi W, Yamasaki R, Ohyagi Y, Kira JI, Oya Y, Yabe H, Nishikawa N, Tobisawa S, Matsuda N, Masuda M, Kugimoto C, Fukushima K, Yano S, Yoshimura J, Doi K, Nakagawa M, Morishita S, Tsuji S, Takashima H. Mutations in MME cause an autosomal-recessive Charcot-Marie-Tooth disease type 2. Ann Neurol 2016; 79:659-72. [PMID: 26991897 PMCID: PMC5069600 DOI: 10.1002/ana.24612] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 01/16/2016] [Accepted: 02/03/2016] [Indexed: 01/12/2023]
Abstract
Objective The objective of this study was to identify new causes of Charcot–Marie–Tooth (CMT) disease in patients with autosomal‐recessive (AR) CMT. Methods To efficiently identify novel causative genes for AR‐CMT, we analyzed 303 unrelated Japanese patients with CMT using whole‐exome sequencing and extracted recessive variants/genes shared among multiple patients. We performed mutation screening of the newly identified membrane metalloendopeptidase (MME) gene in 354 additional patients with CMT. We clinically, genetically, pathologically, and radiologically examined 10 patients with the MME mutation. Results We identified recessive mutations in MME in 10 patients. The MME gene encodes neprilysin (NEP), which is well known to be one of the most prominent beta‐amyloid (Aβ)‐degrading enzymes. All patients had a similar phenotype consistent with late‐onset axonal neuropathy. They showed muscle weakness, atrophy, and sensory disturbance in the lower extremities. All the MME mutations could be loss‐of‐function mutations, and we confirmed a lack/decrease of NEP protein expression in a peripheral nerve. No patients showed symptoms of dementia, and 1 patient showed no excess Aβ in Pittsburgh compound‐B positron emission tomography imaging. Interpretation Our results indicate that loss‐of‐function MME mutations are the most frequent cause of adult‐onset AR‐CMT2 in Japan, and we propose that this new disease should be termed AR‐CMT2T. A loss‐of‐function MME mutation did not cause early‐onset Alzheimer's disease. Identifying the MME mutation responsible for AR‐CMT could improve the rate of molecular diagnosis and the understanding of the molecular mechanisms of CMT. Ann Neurol 2016;79:659–672
Collapse
Affiliation(s)
- Yujiro Higuchi
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Akihiro Hashiguchi
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Junhui Yuan
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Akiko Yoshimura
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Jun Mitsui
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hiroyuki Ishiura
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Masaki Tanaka
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Satoshi Ishihara
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan.,Department of Cardiovascular medicine, Nephrology and Neurology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Hajime Tanabe
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Satoshi Nozuma
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Yuji Okamoto
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Eiji Matsuura
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Ryuichi Ohkubo
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan.,Department of Neurology, Fujimoto General Hospital, Miyazaki, Japan
| | - Saeko Inamizu
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Wataru Shiraishi
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Ryo Yamasaki
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Yasumasa Ohyagi
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Jun-ichi Kira
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Yasushi Oya
- Department of Neurology, National Center Hospital, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Hayato Yabe
- Department of Neurology and Clinical Pharmacology, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Noriko Nishikawa
- Department of Neurology and Clinical Pharmacology, Ehime University Graduate School of Medicine, Ehime, Japan
| | - Shinsuke Tobisawa
- Department of Neurology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan
| | - Nozomu Matsuda
- Department of Neurology, Fukushima Medical University, Fukushima, Japan
| | - Masayuki Masuda
- Department of Neurology, Tokyo Medical University, Tokyo, Japan
| | - Chiharu Kugimoto
- Department of Neurology and Stroke Medicine, Yokohama City University, Yokohama, Japan
| | - Kazuhiro Fukushima
- Department of Home-Care Promotion, Shinshu University School of Medicine, Matsumoto, Japan
| | - Satoshi Yano
- Department of Neurology, Showa University School of Medicine, Tokyo, Japan
| | - Jun Yoshimura
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan
| | - Koichiro Doi
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan
| | - Masanori Nakagawa
- Director of North Medical Center, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Shinichi Morishita
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan
| | - Shoji Tsuji
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hiroshi Takashima
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| |
Collapse
|
15
|
New mutations in DYNC2H1 and WDR60 genes revealed by whole-exome sequencing in two unrelated Sardinian families with Jeune asphyxiating thoracic dystrophy. Clin Chim Acta 2016; 455:172-80. [PMID: 26874042 DOI: 10.1016/j.cca.2016.02.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 01/11/2016] [Accepted: 02/09/2016] [Indexed: 12/30/2022]
Abstract
Jeune asphyxiating thoracic dystrophy (JATD; Jeune syndrome, MIM 208500) is a rare autosomal recessive chondrodysplasia, phenotypically overlapping with short-rib polydactyly syndromes (SRPS). JATD typical hallmarks include skeletal abnormalities such as narrow chest, shortened ribs, limbs shortened bones, extra fingers and toes (polydactyly), as well as extraskeletal manifestations (renal, liver and retinal disease). To date, disease-causing mutations have been found in several genes, highlighting a marked genetic heterogeneity that prevents a molecular diagnosis of the disease in most families. Here, we report the results of whole-exome sequencing (WES) carried out in four JATD cases, belonging to three unrelated families of Sardinian origin. The exome analysis allowed to identify mutations not previously reported in the DYNC2H1 (MIM 603297) and WDR60 (MIM 615462) genes, both codifying for ciliary intraflagellar transport components whose mutations are known to cause Jeune syndrome.
Collapse
|
16
|
Williams HJ, Hurst JR, Ocaka L, James C, Pao C, Chanudet E, Lescai F, Stanescu HC, Kleta R, Rosser E, Bacchelli C, Beales P. The use of whole-exome sequencing to disentangle complex phenotypes. Eur J Hum Genet 2015; 24:298-301. [PMID: 26059842 PMCID: PMC4717198 DOI: 10.1038/ejhg.2015.121] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 03/11/2015] [Accepted: 04/24/2015] [Indexed: 12/30/2022] Open
Abstract
The success of whole-exome sequencing to identify mutations causing single-gene disorders has been well documented. In contrast whole-exome sequencing has so far had limited success in the identification of variants causing more complex phenotypes that seem unlikely to be due to the disruption of a single gene. We describe a family where two male offspring of healthy first cousin parents present a complex phenotype consisting of peripheral neuropathy and bronchiectasis that has not been described previously in the literature. Due to the fact that both children had the same problems in the context of parental consanguinity we hypothesised illness resulted from either X-linked or autosomal recessive inheritance. Through the use of whole-exome sequencing we were able to simplify this complex phenotype and identified a causative mutation (p.R1070*) in the gene periaxin (PRX), a gene previously shown to cause peripheral neuropathy (Dejerine-Sottas syndrome) when this mutation is present. For the bronchiectasis phenotype we were unable to identify a causal single mutation or compound heterozygote, reflecting the heterogeneous nature of this phenotype. In conclusion, in this study we show that whole-exome sequencing has the power to disentangle complex phenotypes through the identification of causative genetic mutations for distinct clinical disorders that were previously masked.
Collapse
Affiliation(s)
- Hywel J Williams
- Centre for Translational Omics - GOSgene, UCL Institute of Child Health, University College London, London, UK
| | - John R Hurst
- UCL Respiratory Medicine, UCL Medical School, London, UK
| | - Louise Ocaka
- Centre for Translational Omics - GOSgene, UCL Institute of Child Health, University College London, London, UK
| | - Chela James
- Centre for Translational Omics - GOSgene, UCL Institute of Child Health, University College London, London, UK
| | - Caroline Pao
- Paediatric Respiratory Medicine, Royal London Hospital, Whitechapel, London, UK
| | - Estelle Chanudet
- Centre for Translational Omics - GOSgene, UCL Institute of Child Health, University College London, London, UK
| | - Francesco Lescai
- Centre for Translational Omics - GOSgene, UCL Institute of Child Health, University College London, London, UK
| | | | - Robert Kleta
- Centre for Translational Omics - GOSgene, UCL Institute of Child Health, University College London, London, UK.,UCL Respiratory Medicine, UCL Medical School, London, UK
| | | | - Elisabeth Rosser
- Department of Clinical Genetics, Great Ormond St Hospital, London, UK
| | - Chiara Bacchelli
- Centre for Translational Omics - GOSgene, UCL Institute of Child Health, University College London, London, UK
| | - Philip Beales
- Centre for Translational Omics - GOSgene, UCL Institute of Child Health, University College London, London, UK
| |
Collapse
|
17
|
Choi YJ, Hyun YS, Nam SH, Koo H, Hong YB, Chung KW, Choi BO. Novel Compound Heterozygous Nonsense PRX Mutations in a Korean Dejerine-Sottas Neuropathy Family. J Clin Neurol 2014; 11:92-6. [PMID: 25628743 PMCID: PMC4302186 DOI: 10.3988/jcn.2015.11.1.92] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 09/09/2013] [Accepted: 09/13/2013] [Indexed: 12/24/2022] Open
Abstract
Background Mutations in the gene encoding periaxin (PRX) are known to cause autosomal recessive Dejerine-Sottas neuropathy (DSN) or Charcot-Marie-Tooth disease type 4F. However, there have been no reports describing Korean patients with these mutations. Case Report We examined a Korean DSN patient with an early-onset, slowly progressive, demyelinating neuropathy with prominent sensory involvement. Whole-exome sequencing and subsequent capillary sequencing revealed novel compound heterozygous nonsense mutations (p.R392X and p.R679X) in PRX. One mutation was transmitted from each of the patient's parents. No unaffected family member had both mutations, and the mutations were not found in healthy controls. Conclusions We believe that these novel compound heterozygous nonsense mutations are the underlying cause of DSN. The clinical, electrophysiologic, and pathologic phenotypes in this family were similar to those described previously for patients with PRX mutations. We have identified the first PRX mutation in a Korean patient with DSN.
Collapse
Affiliation(s)
- Ye Ji Choi
- Department of Neurology, Ewha Womans University School of Medicine, Seoul, Korea
| | - Young Se Hyun
- Department of Biological Science, Kongju National University, Gongju, Korea
| | - Soo Hyun Nam
- Department of Biological Science, Kongju National University, Gongju, Korea
| | - Heasoo Koo
- Department of Pathology, Ewha Womans University School of Medicine, Seoul, Korea
| | - Young Bin Hong
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Ki Wha Chung
- Department of Biological Science, Kongju National University, Gongju, Korea
| | - Byung-Ok Choi
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| |
Collapse
|
18
|
Beutler AS, Kulkarni AA, Kanwar R, Klein CJ, Therneau TM, Qin R, Banck MS, Boora GK, Ruddy KJ, Wu Y, Smalley RL, Cunningham JM, Le-Lindqwister NA, Beyerlein P, Schroth GP, Windebank AJ, Züchner S, Loprinzi CL. Sequencing of Charcot-Marie-Tooth disease genes in a toxic polyneuropathy. Ann Neurol 2014; 76:727-37. [PMID: 25164601 DOI: 10.1002/ana.24265] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2014] [Revised: 08/14/2014] [Accepted: 08/22/2014] [Indexed: 01/11/2023]
Abstract
OBJECTIVE Mutations in Charcot-Marie-Tooth disease (CMT) genes are the cause of rare familial forms of polyneuropathy. Whether allelic variability in CMT genes is also associated with common forms of polyneuropathy-considered "acquired" in medical parlance-is unknown. Chemotherapy-induced peripheral neuropathy (CIPN) occurs commonly in cancer patients and is individually unpredictable. We used CIPN as a clinical model to investigate the association of non-CMT polyneuropathy with CMT genes. METHODS A total of 269 neurologically asymptomatic cancer patients were enrolled in the clinical trial Alliance N08C1 to receive the neurotoxic drug paclitaxel, while undergoing prospective assessments for polyneuropathy. Forty-nine CMT genes were analyzed by targeted massively parallel sequencing of genomic DNA from patient blood. RESULTS A total of 119 (of 269) patients were identified from the 2 ends of the polyneuropathy phenotype distribution: patients that were most and least susceptible to paclitaxel polyneuropathy. The CMT gene PRX was found to be deleteriously mutated in patients who were susceptible to CIPN but not in controls (p = 8 × 10(-3)). Genetic variation in another CMT gene, ARHGEF10, was highly significantly associated with CIPN (p = 5 × 10(-4)). Three nonsynonymous recurrent single nucleotide variants contributed to the ARHGEF10 signal: rs9657362, rs2294039, and rs17683288. Of these, rs9657362 had the strongest effect (odds ratio = 4.8, p = 4 × 10(-4)). INTERPRETATION The results reveal an association of CMT gene allelic variability with susceptibility to CIPN. The findings raise the possibility that other acquired polyneuropathies may also be codetermined by genetic etiological factors, of which some may be related to genes already known to cause the phenotypically related Mendelian disorders of CMT.
Collapse
Affiliation(s)
- Andreas S Beutler
- Department of Oncology, Mayo Clinic, Rochester, MN; Cancer Center, Mayo Clinic, Rochester, MN
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Makrythanasis P, Nelis M, Santoni FA, Guipponi M, Vannier A, Béna F, Gimelli S, Stathaki E, Temtamy S, Mégarbané A, Masri A, Aglan MS, Zaki MS, Bottani A, Fokstuen S, Gwanmesia L, Aliferis K, Bustamante Eduardo M, Stamoulis G, Psoni S, Kitsiou-Tzeli S, Fryssira H, Kanavakis E, Al-Allawi N, Sefiani A, Al Hait S, Elalaoui SC, Jalkh N, Al-Gazali L, Al-Jasmi F, Bouhamed HC, Abdalla E, Cooper DN, Hamamy H, Antonarakis SE. Diagnostic exome sequencing to elucidate the genetic basis of likely recessive disorders in consanguineous families. Hum Mutat 2014; 35:1203-10. [PMID: 25044680 DOI: 10.1002/humu.22617] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 06/30/2014] [Indexed: 01/19/2023]
Abstract
Rare, atypical, and undiagnosed autosomal-recessive disorders frequently occur in the offspring of consanguineous couples. Current routine diagnostic genetic tests fail to establish a diagnosis in many cases. We employed exome sequencing to identify the underlying molecular defects in patients with unresolved but putatively autosomal-recessive disorders in consanguineous families and postulated that the pathogenic variants would reside within homozygous regions. Fifty consanguineous families participated in the study, with a wide spectrum of clinical phenotypes suggestive of autosomal-recessive inheritance, but with no definitive molecular diagnosis. DNA samples from the patient(s), unaffected sibling(s), and the parents were genotyped with a 720K SNP array. Exome sequencing and array CGH (comparative genomic hybridization) were then performed on one affected individual per family. High-confidence pathogenic variants were found in homozygosity in known disease-causing genes in 18 families (36%) (one by array CGH and 17 by exome sequencing), accounting for the clinical phenotype in whole or in part. In the remainder of the families, no causative variant in a known pathogenic gene was identified. Our study shows that exome sequencing, in addition to being a powerful diagnostic tool, promises to rapidly expand our knowledge of rare genetic Mendelian disorders and can be used to establish more detailed causative links between mutant genotypes and clinical phenotypes.
Collapse
Affiliation(s)
- Periklis Makrythanasis
- Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland; Service of Genetic Medicine, University Hospitals of Geneva, Geneva, Switzerland
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
[Charcot-Marie-Tooth disease associated with periaxin mutations (CMT4F): Clinical, electrophysiological and genetic analysis of 24 patients]. Rev Neurol (Paris) 2013; 169:603-12. [PMID: 24011642 DOI: 10.1016/j.neurol.2013.07.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 07/08/2013] [Accepted: 07/09/2013] [Indexed: 01/13/2023]
Abstract
Autosomal recessive Charcot-Marie-Tooth disease (AR-CMT) is often characterized by onset in early childhood and severe phenotype compared to the dominant forms. CMT disease associated with periaxin gene (PRX) is rare and characterized by demyelination limited to the major peripheral nerves. Following the discovery of a high frequency of a specific periaxin gene mutation (E1085fsX4 homozygote) in the Reunion Island, we examined all French patients known as carriers of the periaxin gene mutation. There were 24 patients. Eighteen were from the Reunion Island (6 families and 10 sporadic cases). The six remaining patients were in two families, each with two affected individuals, and two sporadic cases. The series included 17 female and seven male patients. Walking was acquired late, on average at 3.4±1.6 years. One patient never learned to walk. The Charcot Marie Tooth Neuropathy Score (CMTNS) averaged 24.5±8.1. Seven patients had been wheelchair-bound since the age of 24±22. Other symptoms were: scoliosis most often observed after the age of 12 years and sometimes complicated by a restrictive respiratory syndrome; foot deformity in 24 patients; strabismus; glaucoma; myopia. When conduction recordings are available, median nerve motor conduction was slow (<10m/s), associated with a major lengthening of distal latencies. Study of the periaxin gene should be considered in patients with severe demyelinating neuropathy associated with early infantile scoliosis. This disease leads to major disability (29% of patients in this series were wheelchair-bound) and to respiratory insufficiency. Genetic counselling is highly recommended for consanguineous families.
Collapse
|