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Botero V, Tomchik SM. Unraveling neuronal and metabolic alterations in neurofibromatosis type 1. J Neurodev Disord 2024; 16:49. [PMID: 39217323 PMCID: PMC11365184 DOI: 10.1186/s11689-024-09565-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Accepted: 08/02/2024] [Indexed: 09/04/2024] Open
Abstract
Neurofibromatosis type 1 (OMIM 162200) affects ~ 1 in 3,000 individuals worldwide and is one of the most common monogenetic neurogenetic disorders that impacts brain function. The disorder affects various organ systems, including the central nervous system, resulting in a spectrum of clinical manifestations. Significant progress has been made in understanding the disorder's pathophysiology, yet gaps persist in understanding how the complex signaling and systemic interactions affect the disorder. Two features of the disorder are alterations in neuronal function and metabolism, and emerging evidence suggests a potential relationship between them. This review summarizes neurofibromatosis type 1 features and recent research findings on disease mechanisms, with an emphasis on neuronal and metabolic features.
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Affiliation(s)
- Valentina Botero
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, USA
- Department of Neuroscience, Scripps Research, Scripps Florida, Jupiter, FL, USA
- Skaggs School of Chemical and Biological Sciences, Scripps Research, La Jolla, CA, USA
| | - Seth M Tomchik
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA, USA.
- Stead Family Department of Pediatrics, University of Iowa, Iowa City, IA, 52242, USA.
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA, 52242, USA.
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA, 52242, USA.
- Hawk-IDDRC, University of Iowa, Iowa City, IA, 52242, USA.
- Department of Neuroscience, Scripps Research, Scripps Florida, Jupiter, FL, USA.
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Siqueiros-Sanchez M, Dai E, McGhee CA, McNab JA, Raman MM, Green T. Impact of pathogenic variants of the Ras-mitogen-activated protein kinase pathway on major white matter tracts in the human brain. Brain Commun 2024; 6:fcae274. [PMID: 39210910 PMCID: PMC11358645 DOI: 10.1093/braincomms/fcae274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 06/10/2024] [Accepted: 08/12/2024] [Indexed: 09/04/2024] Open
Abstract
Noonan syndrome and neurofibromatosis type 1 are genetic conditions linked to pathogenic variants in genes of the Ras-mitogen-activated protein kinase signalling pathway. Both conditions hyper-activate signalling of the Ras-mitogen-activated protein kinase pathway and exhibit a high prevalence of neuropsychiatric disorders. Further, animal models of Noonan syndrome and neurofibromatosis type 1 and human imaging studies show white matter abnormalities in both conditions. While these findings suggest Ras-mitogen-activated protein kinas pathway hyper-activation effects on white matter, it is unknown whether these effects are syndrome-specific or pathway-specific. To characterize the effect of Noonan syndrome and neurofibromatosis type 1 on human white matter's microstructural integrity and discern potential syndrome-specific influences on microstructural integrity of individual tracts, we collected diffusion-weighted imaging data from children with Noonan syndrome (n = 24), neurofibromatosis type 1 (n = 28) and age- and sex-matched controls (n = 31). We contrasted the clinical groups (Noonan syndrome or neurofibromatosis type 1) and controls using voxel-wise, tract-based and along-tract analyses. Outcomes included voxel-wise, tract-based and along-tract fractional anisotropy, axial diffusivity, radial diffusivity and mean diffusivity. Noonan syndrome and neurofibromatosis type 1 showed similar patterns of reduced fractional anisotropy and increased axial diffusivity, radial diffusivity, and mean diffusivity on white matter relative to controls and different spatial patterns. Noonan syndrome presented a more extensive spatial effect than neurofibromatosis type 1 on white matter integrity as measured by fractional anisotropy. Tract-based analysis also demonstrated differences in effect magnitude with overall lower fractional anisotropy in Noonan syndrome compared to neurofibromatosis type 1 (d = 0.4). At the tract level, Noonan syndrome-specific effects on fractional anisotropy were detected in association tracts (superior longitudinal, uncinate and arcuate fasciculi; P < 0.012), and neurofibromatosis type 1-specific effects were detected in the corpus callosum (P < 0.037) compared to controls. Results from along-tract analyses aligned with results from tract-based analyses and indicated that effects are pervasive along the affected tracts. In conclusion, we find that pathogenic variants in the Ras-mitogen-activated protein kinase pathway are associated with white matter abnormalities as measured by diffusion in the developing brain. Overall, Noonan syndrome and neurofibromatosis type 1 show common effects on fractional anisotropy and diffusion scalars, as well as specific unique effects, namely, on temporoparietal-frontal tracts (intra-hemispheric) in Noonan syndrome and on the corpus callosum (inter-hemispheric) in neurofibromatosis type 1. The observed specific effects not only confirm prior observations from independent cohorts of Noonan syndrome and neurofibromatosis type 1 but also inform on syndrome-specific susceptibility of individual tracts. Thus, these findings suggest potential targets for precise, brain-focused outcome measures for existing medications, such as MEK inhibitors, that act on the Ras-mitogen-activated protein kinase pathway.
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Affiliation(s)
- Monica Siqueiros-Sanchez
- Brain Imaging, Development and Genetic (BRIDGE) Lab, Stanford University School of Medicine, Palo Alto, CA 94306, USA
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Erpeng Dai
- Department of Radiology, Stanford University, Stanford, CA 94305-5105, USA
| | - Chloe A McGhee
- Brain Imaging, Development and Genetic (BRIDGE) Lab, Stanford University School of Medicine, Palo Alto, CA 94306, USA
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jennifer A McNab
- Department of Radiology, Stanford University, Stanford, CA 94305-5105, USA
| | - Mira M Raman
- Brain Imaging, Development and Genetic (BRIDGE) Lab, Stanford University School of Medicine, Palo Alto, CA 94306, USA
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Tamar Green
- Brain Imaging, Development and Genetic (BRIDGE) Lab, Stanford University School of Medicine, Palo Alto, CA 94306, USA
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
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Staedtke V, Anstett K, Bedwell D, Giovannini M, Keeling K, Kesterson R, Kim Y, Korf B, Leier A, McManus ML, Sarnoff H, Vitte J, Walker JA, Plotkin SR, Wallis D. Gene-targeted therapy for neurofibromatosis and schwannomatosis: The path to clinical trials. Clin Trials 2024; 21:51-66. [PMID: 37937606 DOI: 10.1177/17407745231207970] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
Numerous successful gene-targeted therapies are arising for the treatment of a variety of rare diseases. At the same time, current treatment options for neurofibromatosis 1 and schwannomatosis are limited and do not directly address loss of gene/protein function. In addition, treatments have mostly focused on symptomatic tumors, but have failed to address multisystem involvement in these conditions. Gene-targeted therapies hold promise to address these limitations. However, despite intense interest over decades, multiple preclinical and clinical issues need to be resolved before they become a reality. The optimal approaches to gene-, mRNA-, or protein restoration and to delivery to the appropriate cell types remain elusive. Preclinical models that recapitulate manifestations of neurofibromatosis 1 and schwannomatosis need to be refined. The development of validated assays for measuring neurofibromin and merlin activity in animal and human tissues will be critical for early-stage trials, as will the selection of appropriate patients, based on their individual genotypes and risk/benefit balance. Once the safety of gene-targeted therapy for symptomatic tumors has been established, the possibility of addressing a wide range of symptoms, including non-tumor manifestations, should be explored. As preclinical efforts are underway, it will be essential to educate both clinicians and those affected by neurofibromatosis 1/schwannomatosis about the risks and benefits of gene-targeted therapy for these conditions.
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Affiliation(s)
- Verena Staedtke
- Department of Neurology, Johns Hopkins University, Baltimore, MD, USA
| | - Kara Anstett
- Department of Neurology, NYU Grossman School of Medicine, New York, NY, USA
| | - David Bedwell
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Marco Giovannini
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA and Jonsson Comprehensive Cancer Center (JCCC), University of California Los Angeles, Los Angeles, CA, USA
| | - Kim Keeling
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Robert Kesterson
- Department of Cancer Precision Medicine, Pennington Biomedical Research Center, Baton Rouge, LA, USA
| | - YooRi Kim
- Gilbert Family Foundation, Detroit, MI, USA
| | - Bruce Korf
- Department of Genetics, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - André Leier
- Department of Genetics, The University of Alabama at Birmingham, Birmingham, AL, USA
| | | | | | - Jeremie Vitte
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA and Jonsson Comprehensive Cancer Center (JCCC), University of California Los Angeles, Los Angeles, CA, USA
| | - James A Walker
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Scott R Plotkin
- Department of Neurology and Cancer Center, Massachusetts General Hospital, Boston, MA, USA
| | - Deeann Wallis
- Department of Genetics, The University of Alabama at Birmingham, Birmingham, AL, USA
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Wang S, Friedman JM, Suppa P, Buchert R, Mautner VF. White matter is increased in the brains of adults with neurofibromatosis 1. Orphanet J Rare Dis 2022; 17:115. [PMID: 35248131 PMCID: PMC8898512 DOI: 10.1186/s13023-022-02273-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Accepted: 02/27/2022] [Indexed: 11/10/2022] Open
Abstract
Background Neurofibromatosis 1 (NF1) is a rare autosomal dominant disease characterized by increased Schwann cell proliferation in peripheral nerves. Several small studies of brain morphology in children with NF1 have found increased total brain volume, total white matter volume and/or corpus callosum area. Some studies (mostly in children with NF1) also attempted to correlate changes in brain morphology and volume with cognitive or behavioural abnormalities, although the findings were inconsistent. We aimed to characterize alterations in brain volumes by three-dimensional (3D) MRI in adults with NF1 in major intracranial sub-regions. We also aimed to assess the effect of age on these volumes and correlated brain white matter and grey matter volumes with neuropsychometric findings in adults with NF1. Methods We obtained brain volume measurements using 3D magnetic resonance imaging for 351 adults with NF1 and, as a comparison group, 43 adults with neurofibromatosis 2 (NF2) or Schwannomatosis. We assessed a subset of 19 adults with NF1 for clinical severity of NF1 features and neurological problems and conducted psychometric testing for attention deficiencies and intelligence quotient. We compared brain volumes between NF1 patients and controls and correlated volumetric measurements to clinical and psychometric features in the NF1 patients. Results Total brain volume and total and regional white matter volumes were all significantly increased in adults with NF1. Grey matter volume decreased faster with age in adults with NF1 than in controls. Greater total brain volume and white matter volume were correlated with lower attention deficits and higher intelligence quotients in adults with NF1. Conclusion Our findings are consistent with the hypothesis that dysregulation of brain myelin production is a cardinal manifestation of NF1 and that these white matter changes may be functionally important in affected adults. Supplementary Information The online version contains supplementary material available at 10.1186/s13023-022-02273-1.
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Wang S, Mautner VF, Buchert R, Flibotte S, Suppa P, Friedman JM, Heran MKS. Alterations in brain morphology by MRI in adults with neurofibromatosis 1. Orphanet J Rare Dis 2021; 16:462. [PMID: 34727946 PMCID: PMC8561988 DOI: 10.1186/s13023-021-02097-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 10/24/2021] [Indexed: 12/05/2022] Open
Abstract
OBJECTIVE Neurofibromatosis 1 (NF1) is a rare autosomal dominant disease that causes the dysregulated growth of Schwann cells. Most reported studies of brain morphology in NF1 patients have included only children, and clinical implications of the observed changes later in life remain unclear. In this study, we used MRI to characterize brain morphology in adults with NF1. METHODS Planar (2D) MRI measurements of 29 intracranial structures were compared in 389 adults with NF1 and 112 age- and sex-matched unaffected control subjects. The 2D measurements were correlated with volumetric (3D) brain measurements in 99 of the adults with NF1 to help interpret the 2D findings. A subset (n = 70) of these NF1 patients also received psychometric testing for attention deficits and IQ and was assessed for clinical severity of NF1 features and neurological problems. Correlation analysis was performed between the MRI measurements and clinical and psychometric features of these patients. RESULTS Four of nine corpus callosum measurements were significantly greater in adults with NF1 than in sex- and age-matched controls. All seven brainstem measurements were significantly greater in adults with NF1 than in controls. Increased corpus callosum and brainstem 2D morphology were correlated with increased total white matter volume among the NF1 patients. No robust correlations were observed between the 2D size of these structures and clinical or neuropsychometric assessments. CONCLUSION Our findings are consistent with the hypothesis that dysregulation of brain myelin production is an important manifestation of NF1 in adults.
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Affiliation(s)
- Su Wang
- Department of Medical Genetics, University of British Columbia, Children's and Women's Hospital, 4500 Oak Street, Vancouver, BC, V6H 3N1, Canada
| | - Victor-Felix Mautner
- Department of Neurology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Ralph Buchert
- Department of Nuclear Medicine, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Stephane Flibotte
- UBC/LSI Bioinformatics Facility, University of British Columbia, Vancouver, BC, Canada
| | - Per Suppa
- Department of Nuclear Medicine, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Jan M Friedman
- Department of Medical Genetics, University of British Columbia, Children's and Women's Hospital, 4500 Oak Street, Vancouver, BC, V6H 3N1, Canada.
| | - Manraj K S Heran
- Diagnostic and Therapeutic Neuroradiology, University of British Columbia, Vancouver, Canada
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Nemmi F, Cignetti F, Assaiante C, Maziero S, Audic F, Péran P, Chaix Y. Discriminating between neurofibromatosis-1 and typically developing children by means of multimodal MRI and multivariate analyses. Hum Brain Mapp 2019; 40:3508-3521. [PMID: 31077476 DOI: 10.1002/hbm.24612] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 04/08/2019] [Accepted: 04/17/2019] [Indexed: 11/08/2022] Open
Abstract
Neurofibromatosis Type 1 leads to brain anomalies involving both gray and white matter. The extent and granularity of these anomalies, together with their possible impact on brain activity, is still unknown. In this multicentric cross-sectional study we submitted a sample of 42 typically developing and 38 neurofibromatosis-1 children to a multimodal MRI assessment including T1, diffusion weighted and resting state functional sequences. We used a pipeline involving several features selection steps coupled with multivariate statistical analysis (supporting vector machine) to discriminate between the two groups while having interpretable models. We used MRI indexes measuring macro (gray matter volume) and microstructural (fractional anisotropy, mean diffusivity) characteristics of the brain, as well as indexes of brain activity (fractional amplitude of low frequency fluctuations) and connectivity (local and global correlation) at rest. We found that structural indexes could discriminate between the two groups, with the mean diffusivity leading to performance as high as the combination of all structural indexes combined (accuracy = 0.86), while functional indexes had worse performances. The MRI signature of NF1 brain pathology is a combination of gray and white matter abnormalities, as measured with gray matter volume, fractional anisotropy, and mean diffusivity.
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Affiliation(s)
- Federico Nemmi
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, Toulouse, France
| | - Fabien Cignetti
- CNRS, LNC, Aix Marseille Université, Marseille, France.,CNRS, Fédération 3C, Aix Marseille Université, Marseille, France.,CNRS, TIMC-IMAG, Université Grenoble Alpes, Grenoble, France
| | - Christine Assaiante
- CNRS, LNC, Aix Marseille Université, Marseille, France.,CNRS, Fédération 3C, Aix Marseille Université, Marseille, France
| | - Stephanie Maziero
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, Toulouse, France.,URI Octogone-Lordat (EA 4156), Université de Toulouse, Toulouse, France
| | - Fredrique Audic
- Service de Neurologie Pédiatrique, CHU Timone-Enfants, Marseille, France
| | - Patrice Péran
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, Toulouse, France
| | - Yves Chaix
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, Toulouse, France
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8
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Cowell P, Gurd J. Handedness and the Corpus Callosum: A Review and Further Analyses of Discordant Twins. Neuroscience 2018; 388:57-68. [DOI: 10.1016/j.neuroscience.2018.06.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 06/07/2018] [Accepted: 06/08/2018] [Indexed: 11/27/2022]
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Razek AAKA. MR imaging of neoplastic and non-neoplastic lesions of the brain and spine in neurofibromatosis type I. Neurol Sci 2018; 39:821-827. [PMID: 29455398 DOI: 10.1007/s10072-018-3284-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 02/10/2018] [Indexed: 12/14/2022]
Abstract
The aim of this work is to review the MR imaging of neoplastic and non-neoplastic lesions of the brain and spine in neurofibromatosis type I. Neoplastic lesions are optic pathway gliomas, brain stem gliomas, other gliomas of the brain, and peripheral nerve sheath tumors. Structural changes in the brain include unidentified bright objects, macrocephaly, and enlarged corpus callosum. Bony dysplasia changes as sphenoid ridge dysplasia, spinal scalloping, dural ectasia, and meningoceles. Vasculopathy and cortical cerebral and cerebellar malformations of the brain have been reported.
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10
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Klein M, van Donkelaar M, Verhoef E, Franke B. Imaging genetics in neurodevelopmental psychopathology. Am J Med Genet B Neuropsychiatr Genet 2017; 174:485-537. [PMID: 29984470 PMCID: PMC7170264 DOI: 10.1002/ajmg.b.32542] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 02/02/2017] [Accepted: 03/10/2017] [Indexed: 01/27/2023]
Abstract
Neurodevelopmental disorders are defined by highly heritable problems during development and brain growth. Attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorders (ASDs), and intellectual disability (ID) are frequent neurodevelopmental disorders, with common comorbidity among them. Imaging genetics studies on the role of disease-linked genetic variants on brain structure and function have been performed to unravel the etiology of these disorders. Here, we reviewed imaging genetics literature on these disorders attempting to understand the mechanisms of individual disorders and their clinical overlap. For ADHD and ASD, we selected replicated candidate genes implicated through common genetic variants. For ID, which is mainly caused by rare variants, we included genes for relatively frequent forms of ID occurring comorbid with ADHD or ASD. We reviewed case-control studies and studies of risk variants in healthy individuals. Imaging genetics studies for ADHD were retrieved for SLC6A3/DAT1, DRD2, DRD4, NOS1, and SLC6A4/5HTT. For ASD, studies on CNTNAP2, MET, OXTR, and SLC6A4/5HTT were found. For ID, we reviewed the genes FMR1, TSC1 and TSC2, NF1, and MECP2. Alterations in brain volume, activity, and connectivity were observed. Several findings were consistent across studies, implicating, for example, SLC6A4/5HTT in brain activation and functional connectivity related to emotion regulation. However, many studies had small sample sizes, and hypothesis-based, brain region-specific studies were common. Results from available studies confirm that imaging genetics can provide insight into the link between genes, disease-related behavior, and the brain. However, the field is still in its early stages, and conclusions about shared mechanisms cannot yet be drawn.
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Affiliation(s)
- Marieke Klein
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
| | - Marjolein van Donkelaar
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
| | - Ellen Verhoef
- Language and Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
| | - Barbara Franke
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
- Department of Psychiatry, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, The Netherlands
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Petrella LI, Cai Y, Sereno JV, Gonçalves SI, Silva AJ, Castelo-Branco M. Brain and behaviour phenotyping of a mouse model of neurofibromatosis type-1: an MRI/DTI study on social cognition. GENES BRAIN AND BEHAVIOR 2016; 15:637-46. [PMID: 27283753 DOI: 10.1111/gbb.12305] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 05/27/2016] [Accepted: 06/08/2016] [Indexed: 01/03/2023]
Abstract
Neurofibromatosis type-1 (NF1) is a common neurogenetic disorder and an important cause of intellectual disability. Brain-behaviour associations can be examined in vivo using morphometric magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) to study brain structure. Here, we studied structural and behavioural phenotypes in heterozygous Nf1 mice (Nf1(+/-) ) using T2-weighted imaging MRI and DTI, with a focus on social recognition deficits. We found that Nf1(+/-) mice have larger volumes than wild-type (WT) mice in regions of interest involved in social cognition, the prefrontal cortex (PFC) and the caudate-putamen (CPu). Higher diffusivity was found across a distributed network of cortical and subcortical brain regions, within and beyond these regions. Significant differences were observed for the social recognition test. Most importantly, significant structure-function correlations were identified concerning social recognition performance and PFC volumes in Nf1(+/-) mice. Analyses of spatial learning corroborated the previously known deficits in the mutant mice, as corroborated by platform crossings, training quadrant time and average proximity measures. Moreover, linear discriminant analysis of spatial performance identified 2 separate sub-groups in Nf1(+/-) mice. A significant correlation between quadrant time and CPu volumes was found specifically for the sub-group of Nf1(+/-) mice with lower spatial learning performance, suggesting additional evidence for reorganization of this region. We found strong evidence that social and spatial cognition deficits can be associated with PFC/CPu structural changes and reorganization in NF1.
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Affiliation(s)
- L I Petrella
- Institute of Nuclear Science Applied to Health, University of Coimbra, Coimbra, Portugal.,Center for Neuroscience and Cell Biology - Institute of Biomedical Imaging and Life Science (CNC.IBILI), University of Coimbra, Coimbra, Portugal
| | - Y Cai
- Department of Neurobiology, University of California, Los Angeles, CA, USA.,Department of Psychology, University of California, Los Angeles, CA, USA.,Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, CA, USA.,Integrative Center for Learning and Memory, University of California, Los Angeles, CA, USA.,Brain Research Institute, University of California, Los Angeles, CA, USA
| | - J V Sereno
- Institute of Nuclear Science Applied to Health, University of Coimbra, Coimbra, Portugal.,Center for Neuroscience and Cell Biology - Institute of Biomedical Imaging and Life Science (CNC.IBILI), University of Coimbra, Coimbra, Portugal
| | - S I Gonçalves
- Institute of Nuclear Science Applied to Health, University of Coimbra, Coimbra, Portugal.,Center for Neuroscience and Cell Biology - Institute of Biomedical Imaging and Life Science (CNC.IBILI), University of Coimbra, Coimbra, Portugal
| | - A J Silva
- Department of Neurobiology, University of California, Los Angeles, CA, USA.,Department of Psychology, University of California, Los Angeles, CA, USA.,Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, CA, USA.,Integrative Center for Learning and Memory, University of California, Los Angeles, CA, USA.,Brain Research Institute, University of California, Los Angeles, CA, USA
| | - M Castelo-Branco
- Institute of Nuclear Science Applied to Health, University of Coimbra, Coimbra, Portugal. .,Center for Neuroscience and Cell Biology - Institute of Biomedical Imaging and Life Science (CNC.IBILI), University of Coimbra, Coimbra, Portugal.
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de Blank PMK, Berman JI, Fisher MJ. Systemic Chemotherapy and White Matter Integrity in Tracts Associated with Cognition Among Children With Neurofibromatosis Type 1. Pediatr Blood Cancer 2016; 63:818-24. [PMID: 26757156 DOI: 10.1002/pbc.25896] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 11/24/2015] [Accepted: 12/14/2015] [Indexed: 12/13/2022]
Abstract
BACKGROUND Children with neurofibromatosis type 1 (NF1) are predisposed to both brain tumors and cognitive deficits. While changes in white matter integrity after multimodal therapy are associated with cognitive dysfunction, the effect of isolated chemotherapy in NF1 is unknown. To determine whether chemotherapy is associated with white matter microstructural changes, we examined diffusion tensor imaging (DTI) in NF1 subjects. PROCEDURE We reviewed DTI measures in tracts associated with cognition but free from tumor in 24 children with NF1-associated optic pathway gliomas unexposed to surgery or radiation. Twelve age-matched pairs were identified based on exposure to chemotherapy. A paired t-test was used to compare fractional anisotropy (FA) in tracts of interest between subjects with and without chemotherapy exposure. RESULTS On paired t-test, FA was significantly lower in the corpus callosum (P = 0.015) and cerebellothalamic (P = 0.038) tracts of subjects exposed to chemotherapy. There was no effect of age or time from chemotherapy on the difference between groups. In multivariable analysis, FA of these tracts was associated with chemotherapy exposure after adjusting for age, tumor location, and DTI acquisition. In longitudinal measures, FA decreased after chemotherapy exposure while FA increased with age in unexposed subjects. CONCLUSIONS Exposure to low-intensity chemotherapy in NF1 is associated with changes in white matter microstructure in tracts associated with cognition. Future studies should determine whether these changes are associated with cognitive decline. While chemotherapy may spare cognition relative to radiation and surgery, children with NF1 exposed to chemotherapy may benefit from early cognitive testing to allow for earlier intervention.
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Affiliation(s)
- Peter Matthew Kennedy de Blank
- Division of Pediatric Hematology and Oncology, Department of Pediatrics, Rainbow Babies and Children's Hospital, Case Western Reserve University, Cleveland, Ohio
| | - Jeffrey I Berman
- Department of Radiology, The Children's Hospital of Philadelphia and the Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Michael Jay Fisher
- Division of Oncology, Department of Pediatrics, The Children's Hospital of Philadelphia and the Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
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Tomson SN, Schreiner MJ, Narayan M, Rosser T, Enrique N, Silva AJ, Allen GI, Bookheimer SY, Bearden CE. Resting state functional MRI reveals abnormal network connectivity in neurofibromatosis 1. Hum Brain Mapp 2015; 36:4566-81. [PMID: 26304096 PMCID: PMC4619152 DOI: 10.1002/hbm.22937] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Revised: 05/27/2015] [Accepted: 08/03/2015] [Indexed: 01/19/2023] Open
Abstract
Neurofibromatosis type I (NF1) is a genetic disorder caused by mutations in the neurofibromin 1 gene at locus 17q11.2. Individuals with NF1 have an increased incidence of learning disabilities, attention deficits, and autism spectrum disorders. As a single-gene disorder, NF1 represents a valuable model for understanding gene-brain-behavior relationships. While mouse models have elucidated molecular and cellular mechanisms underlying learning deficits associated with this mutation, little is known about functional brain architecture in human subjects with NF1. To address this question, we used resting state functional connectivity magnetic resonance imaging (rs-fcMRI) to elucidate the intrinsic network structure of 30 NF1 participants compared with 30 healthy demographically matched controls during an eyes-open rs-fcMRI scan. Novel statistical methods were employed to quantify differences in local connectivity (edge strength) and modularity structure, in combination with traditional global graph theory applications. Our findings suggest that individuals with NF1 have reduced anterior-posterior connectivity, weaker bilateral edges, and altered modularity clustering relative to healthy controls. Further, edge strength and modular clustering indices were correlated with IQ and internalizing symptoms. These findings suggest that Ras signaling disruption may lead to abnormal functional brain connectivity; further investigation into the functional consequences of these alterations in both humans and in animal models is warranted.
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Affiliation(s)
- Steffie N Tomson
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, UCLA, Los Angeles, California
- Brain Mapping Center, UCLA, Los Angeles, California
- Center for Cognitive Neuroscience, UCLA, Los Angeles, California
| | - Matthew J Schreiner
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, UCLA, Los Angeles, California
- Interdepartmental Neuroscience Program, UCLA, Los Angeles, California
| | - Manjari Narayan
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas
| | - Tena Rosser
- Children's Hospital Los Angeles, Los Angeles, California
- USC Keck School of Medicine, Los Angeles, California
| | - Nicole Enrique
- Center for Cognitive Neuroscience, UCLA, Los Angeles, California
| | - Alcino J Silva
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, UCLA, Los Angeles, California
- Department of Neurobiology, UCLA, Los Angeles, California
- Department of Psychology, UCLA, Los Angeles, California
- Integrative Center for Learning and Memory, UCLA, Los Angeles, California
| | - Genevera I Allen
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas
- Department of Statistics, Rice University, Houston, Texas
- Jan and Dan Duncan Neurological Research Institute, Houston, Texas
| | - Susan Y Bookheimer
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, UCLA, Los Angeles, California
- Center for Cognitive Neuroscience, UCLA, Los Angeles, California
| | - Carrie E Bearden
- Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, UCLA, Los Angeles, California
- Department of Psychology, UCLA, Los Angeles, California
- Integrative Center for Learning and Memory, UCLA, Los Angeles, California
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Templer AK, Titus JB, Gutmann DH. A neuropsychological perspective on attention problems in neurofibromatosis type 1. J Atten Disord 2013; 17:489-96. [PMID: 22354384 DOI: 10.1177/1087054711433422] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cognitive problems are common in children with neurofibromatosis type 1 and they can often complicate treatment. The current literature review examines cognitive functioning in neurofibromatosis type 1, with a specific focus on executive functioning. This includes exploration of how deficits in executive functioning are expressed in children with neurofibromatosis type 1 and how these deficits contrast with ADHD. The value of investigating subcomponents of executive functioning is discussed, as are implications for effective treatment and future research.
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Violante IR, Ribeiro MJ, Silva ED, Castelo-Branco M. Gyrification, cortical and subcortical morphometry in neurofibromatosis type 1: an uneven profile of developmental abnormalities. J Neurodev Disord 2013; 5:3. [PMID: 23406822 PMCID: PMC3599251 DOI: 10.1186/1866-1955-5-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 01/22/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Neurofibromatosis type 1 (NF1) is a monogenic disorder associated with cognitive impairments. In order to understand how mutations in the NF1 gene impact brain structure it is essential to characterize in detail the brain structural abnormalities in patients with NF1. Previous studies have reported contradictory findings and have focused only on volumetric measurements. Here, we investigated the volumes of subcortical structures and the composite dimensions of the cortex through analysis of cortical volume, cortical thickness, cortical surface area and gyrification. METHODS We studied 14 children with NF1 and 14 typically developing children matched for age, gender, IQ and right/left-handedness. Regional subcortical volumes and cortical gyral measurements were obtained using the FreeSurfer software. Between-group differences were evaluated while controlling for the increase in total intracranial volume observed in NF1. RESULTS Subcortical analysis revealed disproportionately larger thalami, right caudate and middle corpus callosum in patients with NF1. Cortical analyses on volume, thickness and surface area were however not indicative of significant alterations in patients. Interestingly, patients with NF1 had significantly lower gyrification indices than typically developing children primarily in the frontal and temporal lobes, but also affecting the insula, cingulate cortex, parietal and occipital regions. CONCLUSIONS The neuroanatomic abnormalities observed were localized to specific brain regions, indicating that particular areas might constitute selective targets for NF1 gene mutations. Furthermore, the lower gyrification indices were accompanied by a disproportionate increase in brain size without the corresponding increase in folding in patients with NF1. Taken together these findings suggest that specific neurodevelopmental processes, such as gyrification, are more vulnerable to NF1 dysfunction than others. The identified changes in brain organization are consistent with the patterns of cognitive dysfunction in the NF1 phenotype.
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Affiliation(s)
- Inês R Violante
- Institute for Biomedical Imaging and Life Sciences, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Coimbra 3000-548, Portugal.
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Abstract
Neurofibromatosis type 1 (NF1) is the most common monogenic disorder in which individuals manifest CNS abnormalities. Affected individuals develop glial neoplasms (optic gliomas, malignant astrocytomas) and neuronal dysfunction (learning disabilities, attention deficits). Nf1 genetically engineered mouse models have revealed the molecular and cellular underpinnings of gliomagenesis, attention deficit, and learning problems with relevance to basic neurobiology. Using NF1 as a model system, these studies have revealed critical roles for the NF1 gene in non-neoplastic cells in the tumor microenvironment, the importance of brain region heterogeneity, novel mechanisms of glial growth regulation, the neurochemical bases for attention deficit and learning abnormalities, and new insights into neural stem cell function. Here we review recent studies, presented at a symposium at the 2012 Society for Neuroscience annual meeting, that highlight unexpected cell biology insights into RAS and cAMP pathway effects on neural progenitor signaling, neuronal function, and oligodendrocyte lineage differentiation.
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Diffusion-Tensor Imaging Derived Metrics of the Corpus Callosum in Children With Neurofibromatosis Type I. AJR Am J Roentgenol 2013; 200:44-9. [DOI: 10.2214/ajr.12.9590] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Karlsgodt KH, Rosser T, Lutkenhoff ES, Cannon TD, Silva A, Bearden CE. Alterations in white matter microstructure in neurofibromatosis-1. PLoS One 2012; 7:e47854. [PMID: 23094098 PMCID: PMC3477133 DOI: 10.1371/journal.pone.0047854] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 09/20/2012] [Indexed: 01/01/2023] Open
Abstract
Neurofibromatosis (NF1) represents the most common single gene cause of learning disabilities. NF1 patients have impairments in frontal lobe based cognitive functions such as attention, working memory, and inhibition. Due to its well-characterized genetic etiology, investigations of NF1 may shed light on neural mechanisms underlying such difficulties in the general population or other patient groups. Prior neuroimaging findings indicate global brain volume increases, consistent with neural over-proliferation. However, little is known about alterations in white matter microstructure in NF1. We performed diffusion tensor imaging (DTI) analyses using tract-based spatial statistics (TBSS) in 14 young adult NF1 patients and 12 healthy controls. We also examined brain volumetric measures in the same subjects. Consistent with prior studies, we found significantly increased overall gray and white matter volume in NF1 patients. Relative to healthy controls, NF1 patients showed widespread reductions in white matter integrity across the entire brain as reflected by decreased fractional anisotropy (FA) and significantly increased absolute diffusion (ADC). When radial and axial diffusion were examined we found pronounced differences in radial diffusion in NF1 patients, indicative of either decreased myelination or increased space between axons. Secondary analyses revealed that FA and radial diffusion effects were of greatest magnitude in the frontal lobe. Such alterations of white matter tracts connecting frontal regions could contribute to the observed cognitive deficits. Furthermore, although the cellular basis of these white matter microstructural alterations remains to be determined, our findings of disproportionately increased radial diffusion against a background of increased white matter volume suggest the novel hypothesis that one potential alteration contributing to increased cortical white matter in NF1 may be looser packing of axons, with or without myelination changes. Further, this indicates that axial and radial diffusivity can uniquely contribute as markers of NF1-associated brain pathology in conjunction with the typically investigated measures.
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Affiliation(s)
- Katherine H Karlsgodt
- Semel Institute for Neuroscience and Behavior, University of California Los Angeles, Los Angeles, California, United States of America.
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Duarte JV, Ribeiro MJ, Violante IR, Cunha G, Silva E, Castelo-Branco M. Multivariate pattern analysis reveals subtle brain anomalies relevant to the cognitive phenotype in neurofibromatosis type 1. Hum Brain Mapp 2012; 35:89-106. [PMID: 22965669 DOI: 10.1002/hbm.22161] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 06/07/2012] [Accepted: 06/13/2012] [Indexed: 11/08/2022] Open
Abstract
Neurofibromatosis Type 1 (NF1) is a common genetic condition associated with cognitive dysfunction. However, the pathophysiology of the NF1 cognitive deficits is not well understood. Abnormal brain structure, including increased total brain volume, white matter (WM) and grey matter (GM) abnormalities have been reported in the NF1 brain. These previous studies employed univariate model-driven methods preventing detection of subtle and spatially distributed differences in brain anatomy. Multivariate pattern analysis allows the combination of information from multiple spatial locations yielding a discriminative power beyond that of single voxels. Here we investigated for the first time subtle anomalies in the NF1 brain, using a multivariate data-driven classification approach. We used support vector machines (SVM) to classify whole-brain GM and WM segments of structural T1 -weighted MRI scans from 39 participants with NF1 and 60 non-affected individuals, divided in children/adolescents and adults groups. We also employed voxel-based morphometry (VBM) as a univariate gold standard to study brain structural differences. SVM classifiers correctly classified 94% of cases (sensitivity 92%; specificity 96%) revealing the existence of brain structural anomalies that discriminate NF1 individuals from controls. Accordingly, VBM analysis revealed structural differences in agreement with the SVM weight maps representing the most relevant brain regions for group discrimination. These included the hippocampus, basal ganglia, thalamus, and visual cortex. This multivariate data-driven analysis thus identified subtle anomalies in brain structure in the absence of visible pathology. Our results provide further insight into the neuroanatomical correlates of known features of the cognitive phenotype of NF1.
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Affiliation(s)
- João V Duarte
- Visual Neuroscience Laboratory, IBILI, Faculty of Medicine, University of Coimbra, Portugal
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Gurd JM, Cowell PE, Lux S, Rezai R, Cherkas L, Ebers GC. fMRI and corpus callosum relationships in monozygotic twins discordant for handedness. Brain Struct Funct 2012; 218:491-509. [PMID: 22527119 DOI: 10.1007/s00429-012-0410-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 03/20/2012] [Indexed: 01/07/2023]
Abstract
To further investigate brain structure and function in 26 handedness discordant monozygotic twin pairs (MzHd), MRI and behavioural assessments were carried out. These showed significant correlation between language-specific functional laterality in inferior and middle frontal gyri, and anterior corpus callosum. Previous studies of handedness discordant monozygotic twins failed to resolve the issue concerning handedness and hemispheric laterality for language due to methodological disparities. The results would be relevant to genetic theories as well as to brain structure:function explanations. MzHd twins underwent MRI and fMRI scanning as well as behavioural assessment of motor performance and cognition. There were significant differences on MRI and fMRI laterality measures, as well as a significant correlation between anterior callosal widths and functional laterality. LH twins showed higher frequencies of atypical functional laterality. There was no significant within-twin pair correlation on fMRI verbal laterality, nor did results show within-twin pair differences on verbal fluency or IQ. Implications for the field of laterality research pertain to frontal hemispheric equipotentiality for verbal processes in healthy individuals. In particular, there can be an apparent lack of cognitive 'cost' to atypical laterality. An fMRI verbal laterality index correlated significantly with corpus callosum widths near Broca's area.
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Affiliation(s)
- J M Gurd
- Nuffield Department of Clinical Neurosciences (Clinical Neurology), University of Oxford, The John Radcliffe Hospital, West Wing, Level 6, Headley Way, Headington, Oxford, OX3 9DU, UK.
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