1
|
Simons C, Dyment D, Bent SJ, Crawford J, D'Hooghe M, Kohlschütter A, Venkateswaran S, Helman G, Poll-The BT, Makowski CC, Ito Y, Kernohan K, Hartley T, Waisfisz Q, Taft RJ, van der Knaap MS, Wolf NI. A recurrent de novo mutation in TMEM106B causes hypomyelinating leukodystrophy. Brain 2019; 140:3105-3111. [PMID: 29186371 DOI: 10.1093/brain/awx314] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 10/05/2017] [Indexed: 12/28/2022] Open
Abstract
Hypomyelinating leukodystrophies are a heterogeneous group of disorders with a clinical presentation that often includes early-onset nystagmus, ataxia and spasticity and a wide range of severity. Using next-generation sequencing techniques and GeneMatcher, we identified four unrelated patients with brain hypomyelination, all with the same recurrent dominant mutation, c.754G>A p.(Asp252Asn), in TMEM106B. The mutation was confirmed as de novo in three of the cases, and the mildly affected father of the fourth affected individual was confirmed as mosaic for this variant. The protein encoded by TMEM106B is poorly characterized but is reported to have a role in regulation of lysosomal trafficking. Polymorphisms in TMEM106B are thought to modify disease onset in frontotemporal dementia, but its relation to myelination is not understood. Clinical presentation in three of the four patients is remarkably benign compared to other hypomyelinating disorders, with congenital nystagmus and mild motor delay. These findings add TMEM106B to the growing list of genes causing hypomyelinating disorders and emphasize the essential role lysosomes play in myelination.
Collapse
Affiliation(s)
- Cas Simons
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland, Australia
| | - David Dyment
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
| | - Stephen J Bent
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland, Australia
| | - Joanna Crawford
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland, Australia
| | - Marc D'Hooghe
- Department of Neurology, General Hospital Sint-Jan, Brugge, Belgium
| | - Alfried Kohlschütter
- Department of Paediatrics, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Sunita Venkateswaran
- Division of Neurology, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
| | - Guy Helman
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland, Australia
| | - Bwee-Tien Poll-The
- Department of Child Neurology, Academic Medical Center, Amsterdam, The Netherlands
| | | | - Yoko Ito
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
| | - Kristin Kernohan
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
| | - Taila Hartley
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
| | - Quinten Waisfisz
- Department of Clinical Genetics, VU University Medical Center, Amsterdam, The Netherlands
| | - Ryan J Taft
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland, Australia.,Illumina Inc, San Diego, California, USA
| | | | - Marjo S van der Knaap
- Department of Child Neurology, VU University Medical Center, and Amsterdam Neuroscience, Amsterdam, The Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, The Netherlands
| | - Nicole I Wolf
- Department of Child Neurology, VU University Medical Center, and Amsterdam Neuroscience, Amsterdam, The Netherlands
| |
Collapse
|
2
|
Simons C, Dyment D, van der Knaap MS, Wolf NI. Reply: The recurrent mutation in TMEM106B also causes hypomyelinating leukodystrophy in China and is a CpG hotspot. Brain 2018; 141:e37. [PMID: 29444246 DOI: 10.1093/brain/awy030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Cas Simons
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland, Australia.,Murdoch Childrens Research Institute, The Royal Children's Hospital Melbourne, Parkville, Victoria, Australia
| | - David Dyment
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
| | - Marjo S van der Knaap
- Department of Child Neurology, VU University Medical Center, and Amsterdam Neuroscience, Amsterdam, The Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, The Netherlands
| | - Nicole I Wolf
- Department of Child Neurology, VU University Medical Center, and Amsterdam Neuroscience, Amsterdam, The Netherlands
| |
Collapse
|
3
|
Duncan ID, Bugiani M, Radcliff AB, Moran JJ, Lopez-Anido C, Duong P, August BK, Wolf NI, van der Knaap MS, Svaren J. A mutation in the Tubb4a gene leads to microtubule accumulation with hypomyelination and demyelination. Ann Neurol 2017; 81:690-702. [PMID: 28393430 DOI: 10.1002/ana.24930] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 04/03/2017] [Accepted: 04/03/2017] [Indexed: 01/08/2023]
Abstract
OBJECTIVE Our goal was to define the genetic cause of the profound hypomyelination in the taiep rat model and determine its relevance to human white matter disease. METHODS Based on previous localization of the taiep mutation to rat chromosome 9, we tested whether the mutation resided within the Tubb4a (β-tubulin 4A) gene, because mutations in the TUBB4A gene have been described in patients with central nervous system hypomyelination. To determine whether accumulation of microtubules led to progressive demyelination, we analyzed the spinal cord and optic nerves of 2-year-old rats by light and electron microscopy. Cerebral white matter from a patient with TUBB4A Asn414Lys mutation and magnetic resonance imaging evidence of severe hypomyelination were studied similarly. RESULTS As the taiep rat ages, there is progressive loss of myelin in the brain and dorsal column of the spinal cord associated with increased oligodendrocyte numbers with accumulation of microtubules. This accumulation involved the entire cell body and distal processes of oligodendrocytes, but there was no accumulation of microtubules in axons. A single point mutation in Tubb4a (p.Ala302Thr) was found in homozygous taiep samples. A similar hypomyelination associated with increased oligodendrocyte numbers and arrays of microtubules in oligodendrocytes was demonstrated in the human patient sample. INTERPRETATION The taiep rat is the first animal model of TUBB4 mutations in humans and a novel system in which to test the mechanism of microtubule accumulation. The finding of microtubule accumulation in a patient with a TUBB4A mutation and leukodystrophy confirms the usefulness of taiep as a model of the human disease. Ann Neurol 2017;81:690-702.
Collapse
Affiliation(s)
- Ian D Duncan
- Department of Medical Sciences, University of Wisconsin-Madison, Madison, WI
| | - Marianna Bugiani
- Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands.,Center for Childhood White Matter Disorders, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, the Netherlands
| | - Abigail B Radcliff
- Department of Medical Sciences, University of Wisconsin-Madison, Madison, WI
| | - John J Moran
- Waisman Center, University of Wisconsin-Madison, Madison, WI
| | | | - Phu Duong
- Waisman Center, University of Wisconsin-Madison, Madison, WI
| | - Benjamin K August
- Electron Microscope Facility, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI
| | - Nicole I Wolf
- Center for Childhood White Matter Disorders, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, the Netherlands.,Department of Child Neurology, VU University Medical Center, Amsterdam, the Netherlands
| | - Marjo S van der Knaap
- Center for Childhood White Matter Disorders, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, the Netherlands.,Department of Child Neurology, VU University Medical Center, Amsterdam, the Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University, Amsterdam, the Netherlands
| | - John Svaren
- Waisman Center, University of Wisconsin-Madison, Madison, WI.,Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI
| |
Collapse
|
4
|
Sending Mixed Signals: The Expanding Role of Molecular Cascade Mutations in Malformations of Cortical Development and Epilepsy. Epilepsy Curr 2016; 16:158-63. [PMID: 27330441 DOI: 10.5698/1535-7511-16.3.158] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Advances in gene sequencing techniques have led to a dramatic increase in the number of signaling cascade and cytoskeletal assembly mutations associated with malformations of cortical development and epilepsy. At the forefront of this research are novel mutations found in regulators of the PI3K/AKT/mTOR cascade and tubulin-associated malformations of cortical development. However, there is limited understanding of the consequences of these newly discovered germline and somatic mutations on cellular function or how these changes in cell biology may lead to areas-large or small-of malformed cortex and recurrent spontaneous seizures. We summarize and discuss what is currently known in this field in an effort to shine light on vast gaps in our knowledge of relatively common causes of cortical malformations.
Collapse
|
5
|
|
6
|
Hamilton EM, Wolf NI, van der Knaap MS. Reply: A novel TUBB4A mutation suggests that genotype-phenotype correlation of H-ABC syndrome needs to be revisited. Brain 2015; 138:e371. [PMID: 25619510 DOI: 10.1093/brain/awu404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Eline M Hamilton
- 1 Department of Child Neurology and Neuroscience Campus Amsterdam, VU University Medical Centre, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Nicole I Wolf
- 1 Department of Child Neurology and Neuroscience Campus Amsterdam, VU University Medical Centre, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Marjo S van der Knaap
- 1 Department of Child Neurology and Neuroscience Campus Amsterdam, VU University Medical Centre, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands 2 Department of Functional Genomics, VU University, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| |
Collapse
|
7
|
Erro R, Hersheson J, Houlden H, Bhatia KP. A novel TUBB4A mutation suggests that genotype-phenotype correlation of H-ABC syndrome needs to be revisited. Brain 2015; 138:e370. [PMID: 25614026 DOI: 10.1093/brain/awu403] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Roberto Erro
- 1 Sobell Department of Motor Neuroscience and Movement Disorders, University College London (UCL) Institute of Neurology, London, UK 2 Dipartimento di Scienze Neurologiche e del Movimento, Università di Verona, Verona, Italy
| | - Joshua Hersheson
- 3 Department of Molecular Neuroscience, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Henry Houlden
- 3 Department of Molecular Neuroscience, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Kailash P Bhatia
- 1 Sobell Department of Motor Neuroscience and Movement Disorders, University College London (UCL) Institute of Neurology, London, UK
| |
Collapse
|