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Atsoniou K, Giannopoulou E, Georganta EM, Skoulakis EMC. Drosophila Contributions towards Understanding Neurofibromatosis 1. Cells 2024; 13:721. [PMID: 38667335 PMCID: PMC11048932 DOI: 10.3390/cells13080721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 04/17/2024] [Accepted: 04/19/2024] [Indexed: 04/28/2024] Open
Abstract
Neurofibromatosis 1 (NF1) is a multisymptomatic disorder with highly variable presentations, which include short stature, susceptibility to formation of the characteristic benign tumors known as neurofibromas, intense freckling and skin discoloration, and cognitive deficits, which characterize most children with the condition. Attention deficits and Autism Spectrum manifestations augment the compromised learning presented by most patients, leading to behavioral problems and school failure, while fragmented sleep contributes to chronic fatigue and poor quality of life. Neurofibromin (Nf1) is present ubiquitously during human development and postnatally in most neuronal, oligodendrocyte, and Schwann cells. Evidence largely from animal models including Drosophila suggests that the symptomatic variability may reflect distinct cell-type-specific functions of the protein, which emerge upon its loss, or mutations affecting the different functional domains of the protein. This review summarizes the contributions of Drosophila in modeling multiple NF1 manifestations, addressing hypotheses regarding the cell-type-specific functions of the protein and exploring the molecular pathways affected upon loss of the highly conserved fly homolog dNf1. Collectively, work in this model not only has efficiently and expediently modelled multiple aspects of the condition and increased understanding of its behavioral manifestations, but also has led to pharmaceutical strategies towards their amelioration.
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Affiliation(s)
- Kalliopi Atsoniou
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center “Alexander Fleming”, 16672 Athens, Greece; (K.A.); (E.G.)
- Laboratory of Experimental Physiology, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - Eleni Giannopoulou
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center “Alexander Fleming”, 16672 Athens, Greece; (K.A.); (E.G.)
| | - Eirini-Maria Georganta
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center “Alexander Fleming”, 16672 Athens, Greece; (K.A.); (E.G.)
| | - Efthimios M. C. Skoulakis
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center “Alexander Fleming”, 16672 Athens, Greece; (K.A.); (E.G.)
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Bildirici Y, Kocaaga A, Karademir-Arslan CN, Yimenicioglu S. Evaluation of Molecular and Clinical Findings in Children With Neurofibromatosis Type 1: Identification of 15 Novel Variants. Pediatr Neurol 2023; 149:69-74. [PMID: 37806041 DOI: 10.1016/j.pediatrneurol.2023.08.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 08/25/2023] [Accepted: 08/26/2023] [Indexed: 10/10/2023]
Abstract
BACKGROUND Neurofibromatosis type 1 (NF1) is the most common neurocutaneous disease and is caused by mutations in the NF1 gene. The most common clinical features of NF1 are pigmentary abnormalities such as café-au-lait spots and inguinal or axillary freckling, cutaneous and plexiform neurofibromas, hamartomas of the iris, optic gliomas, and bone lesions. The aim of this retrospective study was to define the clinical and molecular characteristics of a pediatric sample of NF1, as well as the mutational spectrum and genotype-phenotype correlation. METHODS The study included 40 children with clinically suspected NF1. The patients were screened for NF1 mutations by DNA-based sequencing. In addition, all the patients were studied by multiplex ligation-dependent probe amplification (MLPA) to identify any duplications or deletions in NF1. The demographic, clinical, and genetic features of the children were characterized. RESULTS A total of 40 children with NF1 were included. Of those, 28 were female and 12 were male. The mean age was 8.91 years. An NF1 variant was discovered in 28 of 40 patients (70%). Among these mutations, intronic mutations were the most frequently detected mutations; 15 of these variants had not been previously reported. Only one patient had a whole NF1 gene deletion. CONCLUSIONS This study expands the spectrum of mutations in the NF1 gene. This study also showed that genetic screening using both next-generation sequencing and MLPA had a positive effect on diagnosis and genetic counseling in patients with suspected NF1.
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Affiliation(s)
- Yasar Bildirici
- Department of Pediatrics, Eskişehir City Hospital, Eskişehir, Turkey
| | - Ayca Kocaaga
- Department of Medical Genetics, Eskişehir City Hospital, Eskişehir, Turkey.
| | | | - Sevgi Yimenicioglu
- Department of Pediatric Neurology, Eskişehir City Hospital, Eskişehir, Turkey
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Marmion RA, Simpkins AG, Barrett LA, Denberg DW, Zusman S, Schottenfeld-Roames J, Schüpbach T, Shvartsman SY. Stochastic phenotypes in RAS-dependent developmental diseases. Curr Biol 2023; 33:807-816.e4. [PMID: 36706752 PMCID: PMC10026697 DOI: 10.1016/j.cub.2023.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 12/02/2022] [Accepted: 01/05/2023] [Indexed: 01/27/2023]
Abstract
Germline mutations upregulating RAS signaling are associated with multiple developmental disorders. A hallmark of these conditions is that the same mutation may present vastly different phenotypes in different individuals, even in monozygotic twins. Here, we demonstrate how the origins of such largely unexplained phenotypic variations may be dissected using highly controlled studies in Drosophila that have been gene edited to carry activating variants of MEK, a core enzyme in the RAS pathway. This allowed us to measure the small but consistent increase in signaling output of such alleles in vivo. The fraction of mutation carriers reaching adulthood was strongly reduced, but most surviving animals had normal RAS-dependent structures. We rationalize these results using a stochastic signaling model and support it by quantifying cell fate specification errors in bilaterally symmetric larval trachea, a RAS-dependent structure that allows us to isolate the effects of mutations from potential contributions of genetic modifiers and environmental differences. We propose that the small increase in signaling output shifts the distribution of phenotypes into a regime, where stochastic variation causes defects in some individuals, but not in others. Our findings shed light on phenotypic heterogeneity of developmental disorders caused by deregulated RAS signaling and offer a framework for investigating causal effects of other pathogenic alleles and mild mutations in general.
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Affiliation(s)
- Robert A Marmion
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA.
| | - Alison G Simpkins
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA.
| | - Lena A Barrett
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA.
| | - David W Denberg
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA.
| | - Susan Zusman
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA.
| | | | - Trudi Schüpbach
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
| | - Stanislav Y Shvartsman
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Flatiron Institute, Simons Foundation, New York, NY 10010, USA.
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Sial M, George KJ. A Review of Spinal Lesions in Neurofibromatosis Type 1 in a Large Neurofibromatosis Type 1 Center. World Neurosurg 2023; 169:e157-e163. [PMID: 36334707 DOI: 10.1016/j.wneu.2022.10.100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 10/23/2022] [Accepted: 10/25/2022] [Indexed: 11/06/2022]
Abstract
BACKGROUND Spinal lesions are a known manifestation of neurofibromatosis type 1 (NF1). The aim of this retrospective review was to analyze and report the prevalence of spinal lesions on imaging in a large NF1 center. METHODS The data were collected from a period of 62 months from a cohort of 514 patients. Data were collected from multidisciplinary team meeting reports that included radiologic reports of each patient investigating 20 distinct variables. The prevalence of each of these lesions was calculated, and any statistically significant associations were investigated using the χ2 test. RESULTS Four-hundred forty-seven patients had classic NF1, and 67 patients had spinal NF1. Many of the patients had spinal abnormalities; 25.7% of these patients were found to have dural ectasia, whereas 44.9% of patients had a spinal deformity. A statistically significant association between dural ectasia and spinal neurofibromatosis was established (P < 0.05). An additional statically significant association was established between dural ectasia and spinal deformity (P < 0.00001). The patients with spinal nerve root tumors were identified, and it was found that 49.8% of patients possessed these tumors, whereas 56.3% of these tumors were intraspinal tumors. The most common region affected was the cervical spine, and the most common spinal level was C2. CONCLUSIONS This high prevalence of spinal tumours in mobile areas of the spine is possibly the result of a combination of genetic predisposition and repeated microtraumas resulting in tumor formation. This is the largest reported study of spinal lesions in NF1 based on imaging and offers insights into the etiology and relationships between lesions.
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Affiliation(s)
- Moska Sial
- Departmet of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.
| | - K Joshi George
- Neurosurgery, Salford Royal Foundation Trust, Manchester, United Kingdom
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Tang J, Li N, Li G, Wang J, Yu T, Yao R. Assessment of Rare Genetic Variants to Identify Candidate Modifier Genes Underlying Neurological Manifestations in Neurofibromatosis 1 Patients. Genes (Basel) 2022; 13:genes13122218. [PMID: 36553485 PMCID: PMC9778305 DOI: 10.3390/genes13122218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/30/2022] [Accepted: 11/22/2022] [Indexed: 11/29/2022] Open
Abstract
Neurological phenotypes such as intellectual disability occur in almost half of patients with neurofibromatosis 1 (NF1). Current genotype-phenotype studies have failed to reveal the mechanism underlying this clinical variability. Despite the presence of pathogenic variants of NF1, modifier genes likely determine the occurrence and severity of neurological phenotypes. Exome sequencing data were used to identify genetic variants in 13 NF1 patients and 457 healthy controls, and this information was used to identify candidate modifier genes underlying neurological phenotypes based on an optimal sequence kernel association test. Thirty-six genes were identified as significant modifying factors in patients with neurological phenotypes and all are highly expressed in the nervous system. A review of the literature confirmed that 19 genes including CUL7, DPH1, and BCO1 are clearly associated with the alteration of neurological functioning and development. Our study revealed the enrichment of rare variants of 19 genes closely related to neurological development and functioning in NF1 patients with neurological phenotypes, indicating possible modifier genes and variants affecting neurodevelopment. Further studies on rare genetic variants of candidate modifier genes may help explain the clinical heterogeneity of NF1.
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Kingdom R, Wright CF. Incomplete Penetrance and Variable Expressivity: From Clinical Studies to Population Cohorts. Front Genet 2022; 13:920390. [PMID: 35983412 PMCID: PMC9380816 DOI: 10.3389/fgene.2022.920390] [Citation(s) in RCA: 77] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 06/09/2022] [Indexed: 12/20/2022] Open
Abstract
The same genetic variant found in different individuals can cause a range of diverse phenotypes, from no discernible clinical phenotype to severe disease, even among related individuals. Such variants can be said to display incomplete penetrance, a binary phenomenon where the genotype either causes the expected clinical phenotype or it does not, or they can be said to display variable expressivity, in which the same genotype can cause a wide range of clinical symptoms across a spectrum. Both incomplete penetrance and variable expressivity are thought to be caused by a range of factors, including common variants, variants in regulatory regions, epigenetics, environmental factors, and lifestyle. Many thousands of genetic variants have been identified as the cause of monogenic disorders, mostly determined through small clinical studies, and thus, the penetrance and expressivity of these variants may be overestimated when compared to their effect on the general population. With the wealth of population cohort data currently available, the penetrance and expressivity of such genetic variants can be investigated across a much wider contingent, potentially helping to reclassify variants that were previously thought to be completely penetrant. Research into the penetrance and expressivity of such genetic variants is important for clinical classification, both for determining causative mechanisms of disease in the affected population and for providing accurate risk information through genetic counseling. A genotype-based definition of the causes of rare diseases incorporating information from population cohorts and clinical studies is critical for our understanding of incomplete penetrance and variable expressivity. This review examines our current knowledge of the penetrance and expressivity of genetic variants in rare disease and across populations, as well as looking into the potential causes of the variation seen, including genetic modifiers, mosaicism, and polygenic factors, among others. We also considered the challenges that come with investigating penetrance and expressivity.
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Affiliation(s)
| | - Caroline F. Wright
- Institute of Biomedical and Clinical Science, Royal Devon & Exeter Hospital, University of Exeter Medical School, Exeter, United Kingdom
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Billar RJ, Manoubi W, Kant SG, Wijnen RMH, Demirdas S, Schnater JM. Association between pectus excavatum and congenital genetic disorders: A systematic review and practical guide for the treating physician. J Pediatr Surg 2021; 56:2239-2252. [PMID: 34039477 DOI: 10.1016/j.jpedsurg.2021.04.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 04/13/2021] [Accepted: 04/18/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Pectus excavatum (PE) could be part of a genetic disorder, which then has implications regarding comorbidity, the surgical correction of PE, and reproductive choices. However, referral of a patient presenting with PE for genetic analysis is often delayed because additional crucial clinical signs may be subtle or even missed in syndromic patients. We reviewed the literature to inventory known genetic disorders associated with PE and create a standardized protocol for clinical evaluation. METHODS A systematic literature search was performed in electronic databases. Genetic disorders were considered associated with PE if studies reported at least five cases with PE. Characteristics of each genetic disorder were extracted from the literature and the OMIM database in order to create a practical guide for the clinician. RESULTS After removal of duplicates from the initial search, 1632 citations remained. Eventually, we included 119 full text articles, representing 20 different genetic disorders. Relevant characteristics and important clinical signs of each genetic disorder were summarized providing a standardized protocol in the form of a scoring list. The most important clinical sign was a positive family history for PE and/or congenital heart defect. CONCLUSIONS Twenty unique genetic disorders have been found associated with PE. We have created a scoring list for the clinician that systematically evaluates crucial clinical signs, thereby facilitating decision making for referral to a clinical geneticist.
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Affiliation(s)
- Ryan J Billar
- Erasmus University Medical Center - Sophia Children's Hospital, department of Paediatric Surgery Rotterdam, Netherlands
| | - Wiem Manoubi
- Erasmus University Medical Centre, department of Neuroscience, Rotterdam, Netherlands
| | - Sarina G Kant
- Erasmus University Medical Centre, department of Clinical Genetics, Rotterdam, Netherlands
| | - René M H Wijnen
- Erasmus University Medical Center - Sophia Children's Hospital, department of Paediatric Surgery Rotterdam, Netherlands
| | - Serwet Demirdas
- Erasmus University Medical Centre, department of Clinical Genetics, Rotterdam, Netherlands
| | - Johannes M Schnater
- Erasmus University Medical Center - Sophia Children's Hospital, department of Paediatric Surgery Rotterdam, Netherlands.
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Fowlkes JL, Thrailkill KM, Bunn RC. RASopathies: The musculoskeletal consequences and their etiology and pathogenesis. Bone 2021; 152:116060. [PMID: 34144233 PMCID: PMC8316423 DOI: 10.1016/j.bone.2021.116060] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 06/07/2021] [Accepted: 06/10/2021] [Indexed: 01/07/2023]
Abstract
The RASopathies comprise an ever-growing number of clinical syndromes resulting from germline mutations in components of the RAS/MAPK signaling pathway. While multiple organs and tissues may be affected by these mutations, this review will focus on how these mutations specifically impact the musculoskeletal system. Herein, we review the genetics and musculoskeletal phenotypes of these syndromes in humans. We discuss how mutations in the RASopathy syndromes have been studied in translational mouse models. Finally, we discuss how signaling molecules within the RAS/MAPK pathway are involved in normal and abnormal bone biology in the context of osteoblasts, osteoclasts and chondrocytes.
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Affiliation(s)
- John L Fowlkes
- University of Kentucky Barnstable Brown Diabetes Center, Department of Pediatrics, University of Kentucky College of Medicine, Lexington, KY 40536, United States of America.
| | - Kathryn M Thrailkill
- University of Kentucky Barnstable Brown Diabetes Center, Department of Pediatrics, University of Kentucky College of Medicine, Lexington, KY 40536, United States of America
| | - R Clay Bunn
- University of Kentucky Barnstable Brown Diabetes Center, Department of Pediatrics, University of Kentucky College of Medicine, Lexington, KY 40536, United States of America
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Martin S, Allen T, Toledo-Tamula MA, Struemph K, Reda S, Wolters PL, Baldwin A, Quinn M, Widemann BC. Acceptance and commitment therapy for adolescents and adults with neurofibromatosis type 1, plexiform neurofibromas, and chronic pain: Results of a randomized controlled trial. JOURNAL OF CONTEXTUAL BEHAVIORAL SCIENCE 2021. [DOI: 10.1016/j.jcbs.2021.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Distinctive epigenomic alterations in NF1-deficient cutaneous and plexiform neurofibromas drive differential MKK/p38 signaling. Epigenetics Chromatin 2021; 14:7. [PMID: 33436083 PMCID: PMC7805211 DOI: 10.1186/s13072-020-00380-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 12/17/2020] [Indexed: 11/18/2022] Open
Abstract
Benign peripheral nerve sheath tumors are the clinical hallmark of Neurofibromatosis Type 1. They account for substantial morbidity and mortality in NF1. Cutaneous (CNF) and plexiform neurofibromas (PNF) share nearly identical histology, but maintain different growth rates and risk of malignant conversion. The reasons for this disparate clinical behavior are not well explained by recent genome or transcriptome profiling studies. We hypothesized that CNFs and PNFs are epigenetically distinct tumor types that exhibit differential signaling due to genome-wide and site-specific methylation events. We interrogated the methylation profiles of 45 CNFs and 17 PNFs from NF1 subjects with the Illumina EPIC 850K methylation array. Based on these profiles, we confirm that CNFs and PNFs are epigenetically distinct tumors with broad differences in higher-order chromatin states and specific methylation events altering genes involved in key biological and cellular processes, such as inflammation, RAS/MAPK signaling, actin cytoskeleton rearrangement, and oxytocin signaling. Based on our identification of two separate DMRs associated with alternative leading exons in MAP2K3, we demonstrate differential RAS/MKK3/p38 signaling between CNFs and PNFs. Epigenetic reinforcement of RAS/MKK/p38 was a defining characteristic of CNFs leading to pro-inflammatory signaling and chromatin conformational changes, whereas PNFs signaled predominantly through RAS/MEK. Tumor size also correlated with specific CpG methylation events. Taken together, these findings confirm that NF1 deficiency influences the epigenetic regulation of RAS signaling fates, accounting for observed differences in CNF and PNF clinical behavior. The extension of these findings is that CNFs may respond differently than PNFs to RAS-targeted therapeutics raising the possibility of targeting p38-mediated inflammation for CNF treatment.
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Bergoug M, Doudeau M, Godin F, Mosrin C, Vallée B, Bénédetti H. Neurofibromin Structure, Functions and Regulation. Cells 2020; 9:cells9112365. [PMID: 33121128 PMCID: PMC7692384 DOI: 10.3390/cells9112365] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 10/21/2020] [Accepted: 10/26/2020] [Indexed: 12/13/2022] Open
Abstract
Neurofibromin is a large and multifunctional protein encoded by the tumor suppressor gene NF1, mutations of which cause the tumor predisposition syndrome neurofibromatosis type 1 (NF1). Over the last three decades, studies of neurofibromin structure, interacting partners, and functions have shown that it is involved in several cell signaling pathways, including the Ras/MAPK, Akt/mTOR, ROCK/LIMK/cofilin, and cAMP/PKA pathways, and regulates many fundamental cellular processes, such as proliferation and migration, cytoskeletal dynamics, neurite outgrowth, dendritic-spine density, and dopamine levels. The crystallographic structure has been resolved for two of its functional domains, GRD (GAP-related (GTPase-activating protein) domain) and SecPH, and its post-translational modifications studied, showing it to be localized to several cell compartments. These findings have been of particular interest in the identification of many therapeutic targets and in the proposal of various therapeutic strategies to treat the symptoms of NF1. In this review, we provide an overview of the literature on neurofibromin structure, function, interactions, and regulation and highlight the relationships between them.
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Woycinck Kowalski T, Brussa Reis L, Finger Andreis T, Ashton-Prolla P, Rosset C. Systems Biology Approaches Reveal Potential Phenotype-Modifier Genes in Neurofibromatosis Type 1. Cancers (Basel) 2020; 12:cancers12092416. [PMID: 32858845 PMCID: PMC7565824 DOI: 10.3390/cancers12092416] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/18/2020] [Accepted: 07/20/2020] [Indexed: 12/18/2022] Open
Abstract
Neurofibromatosis type (NF1) is a syndrome characterized by varied symptoms, ranging from mild to more aggressive phenotypes. The variation is not explained only by genetic and epigenetic changes in the NF1 gene and the concept of phenotype-modifier genes in extensively discussed in an attempt to explain this variability. Many datasets and tools are already available to explore the relationship between genetic variation and disease, including systems biology and expression data. To suggest potential NF1 modifier genes, we selected proteins related to NF1 phenotype and NF1 gene ontologies. Protein–protein interaction (PPI) networks were assembled, and network statistics were obtained by using forward and reverse genetics strategies. We also evaluated the heterogeneous networks comprising the phenotype ontologies selected, gene expression data, and the PPI network. Finally, the hypothesized phenotype-modifier genes were verified by a random-walk mathematical model. The network statistics analyses combined with the forward and reverse genetics strategies, and the assembly of heterogeneous networks, resulted in ten potential phenotype-modifier genes: AKT1, BRAF, EGFR, LIMK1, PAK1, PTEN, RAF1, SDC2, SMARCA4, and VCP. Mathematical models using the random-walk approach suggested SDC2 and VCP as the main candidate genes for phenotype-modifiers.
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Affiliation(s)
- Thayne Woycinck Kowalski
- Laboratório de Medicina Genômica, Centro de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Rio Grande do Sul, Brazil; (T.W.K.); (L.B.R.); (T.F.A.); (P.A.-P.)
- Programa de Pós-Graduação em Genética e Biologia Molecular, PPGBM, Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre 91501-970, Rio Grande do Sul, Brazil
- CESUCA - Faculdade Inedi, Cachoeirinha 94935-630, Rio Grande do Sul, Brazil
| | - Larissa Brussa Reis
- Laboratório de Medicina Genômica, Centro de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Rio Grande do Sul, Brazil; (T.W.K.); (L.B.R.); (T.F.A.); (P.A.-P.)
- Programa de Pós-Graduação em Genética e Biologia Molecular, PPGBM, Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre 91501-970, Rio Grande do Sul, Brazil
| | - Tiago Finger Andreis
- Laboratório de Medicina Genômica, Centro de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Rio Grande do Sul, Brazil; (T.W.K.); (L.B.R.); (T.F.A.); (P.A.-P.)
- Programa de Pós-Graduação em Genética e Biologia Molecular, PPGBM, Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre 91501-970, Rio Grande do Sul, Brazil
| | - Patricia Ashton-Prolla
- Laboratório de Medicina Genômica, Centro de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Rio Grande do Sul, Brazil; (T.W.K.); (L.B.R.); (T.F.A.); (P.A.-P.)
- Programa de Pós-Graduação em Genética e Biologia Molecular, PPGBM, Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre 91501-970, Rio Grande do Sul, Brazil
- Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Rio Grande do Sul, Brazil
| | - Clévia Rosset
- Laboratório de Medicina Genômica, Centro de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Rio Grande do Sul, Brazil; (T.W.K.); (L.B.R.); (T.F.A.); (P.A.-P.)
- Unidade de Pesquisa Laboratorial, Centro de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre 90035-007, Rio Grande do Sul, Brazil
- Correspondence: ; Tel.: +55-51-3359-7661
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Neurofibromatosis Type 1 Implicates Ras Pathways in the Genetic Architecture of Neurodevelopmental Disorders. Behav Genet 2020; 50:191-202. [DOI: 10.1007/s10519-020-09991-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Accepted: 01/04/2020] [Indexed: 01/12/2023]
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Examination of the genetic factors underlying the cognitive variability associated with neurofibromatosis type 1. Genet Med 2020; 22:889-897. [PMID: 32015538 PMCID: PMC7200599 DOI: 10.1038/s41436-020-0752-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 01/20/2020] [Accepted: 01/21/2020] [Indexed: 12/18/2022] Open
Abstract
Purpose Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder associated with cognitive deficits. The NF1 cognitive phenotype is generally considered to be highly variable, possibly due to the observed T2-weighted hyperintensities, loss of heterozygosity, NF1-specific genetic modifiers, or allelic imbalance. Methods We investigated cognitive variability and assessed the contribution of genetic factors by performing a retrospective cohort study and a monozygotic twin case series. We included data of 497 children with genetically confirmed NF1 and an IQ assessment, including 12 monozygotic twin and 17 sibling sets. Results Individuals carrying an NF1 chromosomal microdeletion showed significant lower full-scale IQ (FSIQ) scores than individuals carrying intragenic pathogenic NF1 variants. For the intragenic subgroup, the variability in cognitive ability and the correlation of IQ between monozygotic NF1 twin pairs or between NF1 siblings is similar to the general population. Conclusions The variance and heritability of IQ in individuals with NF1 are similar to that of the general population, and hence mostly driven by genetic background differences. The only factor that significantly attenuates IQ in NF1 individuals is the NF1 chromosomal microdeletion genotype. Implications for clinical management are that individuals with intragenic NF1 variants that score <1.5–2 SD below the mean of the NF1 population should be screened for additional causes of cognitive disability.
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NF1 patient missense variants predict a role for ATM in modifying neurofibroma initiation. Acta Neuropathol 2020; 139:157-174. [PMID: 31664505 DOI: 10.1007/s00401-019-02086-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 10/11/2019] [Accepted: 10/15/2019] [Indexed: 01/01/2023]
Abstract
In Neurofibromatosis type 1, NF1 gene mutations in Schwann cells (SC) drive benign plexiform neurofibroma (PNF), and no additional SC changes explain patient-to-patient variability in tumor number. Evidence from twin studies suggests that variable expressivity might be caused by unidentified modifier genes. Whole exome sequencing of SC and fibroblast DNA from the same resected PNFs confirmed biallelic SC NF1 mutations; non-NF1 somatic SC variants were variable and present at low read number. We identified frequent germline variants as possible neurofibroma modifier genes. Genes harboring variants were validated in two additional cohorts of NF1 patients and by variant burden test. Genes including CUBN, CELSR2, COL14A1, ATR and ATM also showed decreased gene expression in some neurofibromas. ATM-relevant DNA repair defects were also present in a subset of neurofibromas with ATM variants, and in some neurofibroma SC. Heterozygous ATM G2023R or homozygous S707P variants reduced ATM protein expression in heterologous cells. In mice, genetic Atm heterozygosity promoted Schwann cell precursor self-renewal and increased tumor formation in vivo, suggesting that ATM variants contribute to neurofibroma initiation. We identify germline variants, rare in the general population, overrepresented in NF1 patients with neurofibromas. ATM and other identified genes are candidate modifiers of PNF pathogenesis.
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16
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Toledano-Alhadef H, Mautner VF, Gugel I, Zipfel J, Haas-Lude K, Constantini S, Schuhmann MU. Role, function and challenges of multidisciplinary centres for rare diseases exemplified for neurofibromatosis type 1 syndrome. Childs Nerv Syst 2020; 36:2279-2284. [PMID: 32514759 PMCID: PMC7276654 DOI: 10.1007/s00381-020-04708-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 05/26/2020] [Indexed: 12/24/2022]
Abstract
PURPOSE Neurofibromatosis type 1 (NF1) syndrome is a common rare/orphan disease that manifests itself early in the paediatric age. It imposes a considerable burden upon patients as well as on caregivers. Decisions regarding optimal care often rely on several medical instances working together as a team. METHODS The authors reviewed the literature and supplied a description of their own clinical work at the NF1 centres. RESULTS The experience of a multidisciplinary teamwork of three NF centres was summarized in order to enhance awareness for possible multidisciplinary ways of delivery of health and health-related aspects of care to NF1 patients. Both population-focused research centres and family-focused centres were reviewed. CONCLUSIONS Chronic rare diseases that start in the paediatric age mandate long-term follow-up most often by several disciplines. NF1 syndrome is an example of a multidisciplinary centre in order to enhance the quality of care.
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Affiliation(s)
- Hagit Toledano-Alhadef
- Gilbert Israeli and International Neurofibromatosis Centre, Dana-Dwek Children's Hospital, Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel
- Paediatric Neurology and Child Development Center, Dana-Dwek Children's Hospital, Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Victor-Felix Mautner
- International Neurofibromatosis Centre, Department of Neurology, University Hospital Hamburg Eppendorf, Hamburg, Germany
| | - Isabel Gugel
- Centre of Neurofibromatosis at the Centre of Rare Diseases, Tuebingen University Hospital, Tuebingen, Germany
- Department of Neurosurgery, Tuebingen University Hospital, Tuebingen, Germany
| | - Julian Zipfel
- Centre of Neurofibromatosis at the Centre of Rare Diseases, Tuebingen University Hospital, Tuebingen, Germany
- Department of Neurosurgery, Tuebingen University Hospital, Tuebingen, Germany
- Division of Paediatric Neurosurgery, Department of Neurosurgery, Tuebingen University Hospital, Tuebingen, Germany
| | - Karin Haas-Lude
- Centre of Neurofibromatosis at the Centre of Rare Diseases, Tuebingen University Hospital, Tuebingen, Germany
- Department of Paediatric Neurology and Developmental Medicine, University Children's Hospital, Tuebingen, Germany
| | - Shlomi Constantini
- Gilbert Israeli and International Neurofibromatosis Centre, Dana-Dwek Children's Hospital, Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel.
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
- Department of Paediatric Neurosurgery, Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel.
| | - Martin U Schuhmann
- Centre of Neurofibromatosis at the Centre of Rare Diseases, Tuebingen University Hospital, Tuebingen, Germany
- Department of Neurosurgery, Tuebingen University Hospital, Tuebingen, Germany
- Division of Paediatric Neurosurgery, Department of Neurosurgery, Tuebingen University Hospital, Tuebingen, Germany
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17
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Lobbous M, Bernstock JD, Coffee E, Friedman GK, Metrock LK, Chagoya G, Elsayed G, Nakano I, Hackney JR, Korf BR, Nabors LB. An Update on Neurofibromatosis Type 1-Associated Gliomas. Cancers (Basel) 2020; 12:E114. [PMID: 31906320 PMCID: PMC7017116 DOI: 10.3390/cancers12010114] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 12/26/2019] [Accepted: 12/29/2019] [Indexed: 12/22/2022] Open
Abstract
Neurofibromatosis type 1 (NF1) is an autosomal dominant tumor predisposition syndrome that affects children and adults. Individuals with NF1 are at high risk for central nervous system neoplasms including gliomas. The purpose of this review is to discuss the spectrum of intracranial gliomas arising in individuals with NF1 with a focus on recent preclinical and clinical data. In this review, possible mechanisms of gliomagenesis are discussed, including the contribution of different signaling pathways and tumor microenvironment. Furthermore, we discuss the recent notable advances in the developing therapeutic landscape for NF1-associated gliomas including clinical trials and collaborative efforts.
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Affiliation(s)
- Mina Lobbous
- Division of Neuro Oncology, Department of Neurology, University of Alabama at Birmingham, 510 20th Street South, Faculty Office Tower Suite 1020 Birmingham, Birmingham, AL 35294, USA; (E.C.)
| | - Joshua D. Bernstock
- Department of Neurosurgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA;
| | - Elizabeth Coffee
- Division of Neuro Oncology, Department of Neurology, University of Alabama at Birmingham, 510 20th Street South, Faculty Office Tower Suite 1020 Birmingham, Birmingham, AL 35294, USA; (E.C.)
| | - Gregory K. Friedman
- Division of Pediatric Hematology and Oncology, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (G.K.F.); (L.K.M.)
| | - Laura K. Metrock
- Division of Pediatric Hematology and Oncology, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (G.K.F.); (L.K.M.)
| | - Gustavo Chagoya
- Department of Neurosurgery, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (G.C.); (G.E.); (I.N.)
| | - Galal Elsayed
- Department of Neurosurgery, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (G.C.); (G.E.); (I.N.)
| | - Ichiro Nakano
- Department of Neurosurgery, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (G.C.); (G.E.); (I.N.)
| | - James R. Hackney
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294, USA;
| | - Bruce R. Korf
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA;
| | - Louis B. Nabors
- Division of Neuro Oncology, Department of Neurology, University of Alabama at Birmingham, 510 20th Street South, Faculty Office Tower Suite 1020 Birmingham, Birmingham, AL 35294, USA; (E.C.)
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18
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Kang E, Kim YM, Seo GH, Oh A, Yoon HM, Ra YS, Kim EK, Kim H, Heo SH, Kim GH, Osborn MJ, Tolar J, Yoo HW, Lee BH. Phenotype categorization of neurofibromatosis type I and correlation to NF1 mutation types. J Hum Genet 2019; 65:79-89. [PMID: 31776437 DOI: 10.1038/s10038-019-0695-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 11/04/2019] [Accepted: 11/12/2019] [Indexed: 01/17/2023]
Abstract
Neurofibromatosis type 1 (NF1) is caused by heterozygous mutation in the NF1 gene. NF1 is one of the most common human genetic diseases. However, the overall genotype-phenotype correlation has not been known, due to a wide spectrum of genotypic and phenotypic heterogeneity. Here we describe the detailed clinical and genetic features of 427 Korean NF1 patients from 389 unrelated families. Long range PCR and sequencing of genomic DNA with multiplex ligation-dependent probe amplification analysis identified 250 different NF1 mutations in 363 families (93%), including 94 novel mutations. With an emphasis on phenotypes requiring medical attention (classified and termed: NF1+), we investigated the correlation of NF1+ and mutation types. NF1+ was more prevalent in patients with truncating/splicing mutations and large deletions than in those with missense mutations (59.6%, 64.3% vs. 36.6%, p = 0.001). This difference was especially significant in the patients younger than age 19 years. The number of items in NF1+ was a higher in the former groups (0.95 ± 0.06, 1.18 ± 0.20 vs. 0.56 ± 0.10, p = 0.002). These results suggest that mutation types are associated not only with higher prevalence of severe phenotypes in NF1 but also with their earlier onset.
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Affiliation(s)
- Eungu Kang
- Department of Pediatrics, Korea University Ansan Hospital, Korea University College of Medicine, Ansan, Republic of Korea
| | - Yoon-Myung Kim
- Department of Pediatrics, Gangneung Asan Hospital, Gangneung, Republic of Korea
| | - Go Hun Seo
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, 88, Olympic-ro 43-Gil, Songpa-Gu, Seoul, 05505, Republic of Korea
| | - Arum Oh
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, 88, Olympic-ro 43-Gil, Songpa-Gu, Seoul, 05505, Republic of Korea
| | - Hee Mang Yoon
- Department of Radiology and Research Institute of Radiology, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Young-Shin Ra
- Departments of Neurosurgery, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Eun Key Kim
- Department of Plastic Surgery, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Heyry Kim
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, 88, Olympic-ro 43-Gil, Songpa-Gu, Seoul, 05505, Republic of Korea
| | - Sun-Hee Heo
- Asan Institute for Life Sciences, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Gu-Hwan Kim
- Medical Genetics Center, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Mark J Osborn
- Department of Pediatrics, Division of Blood and Marrow Transplantation, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Jakub Tolar
- Department of Pediatrics, Division of Blood and Marrow Transplantation, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Han-Wook Yoo
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, 88, Olympic-ro 43-Gil, Songpa-Gu, Seoul, 05505, Republic of Korea.,Medical Genetics Center, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Beom Hee Lee
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, 88, Olympic-ro 43-Gil, Songpa-Gu, Seoul, 05505, Republic of Korea. .,Medical Genetics Center, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Republic of Korea.
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19
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Pendergrass C, Peraza J. A comparison of neuropsychological function between monozygotic twins with neurofibromatosis, type 1: A case report. Clin Neuropsychol 2019; 34:1049-1064. [PMID: 31154935 DOI: 10.1080/13854046.2019.1621381] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Objective: Neurofibromatosis type 1 (NF-1) is an autosomal dominant genetic disorder that commonly presents with cognitive impairment and greater rates of learning disorders and academic difficulty compared to the general population. Investigations of neurological and physiological expression of NF-1 in monozygotic twins identified intrapair similarities and differences. Monozygotic twins with NF-1 have been found to have similar IQ scores as well as concordant diagnoses of attention-deficit/hyperactivity disorder and learning disabilities. There have been no previous reports on similarities and differences in neuropsychological profiles between monozygotic twins with NF-1. The purpose of this article is to examine the results of comprehensive neuropsychological evaluations for a pair of monozygotic twins with NF-1.Method: A pair of 19-year-old female, African-American monozygotic twins with NF-1 underwent neuropsychological evaluations in an outpatient clinic. Findings are reported following the CAse REport (CARE) guidelines.Results: The twins demonstrated similar impairment in processing speed, working memory, and attention span; however, differences also were found.Conclusions: Intrapair similarities and differences on neuropsychological assessment were found between monozygotic twins with NF-1. Primary deficits were suggestive of a frontal-subcortical pattern and could be consistent with remote neuroimaging. When differences did occur, performance was typically better for Twin A, who had also showed greater improvement on neuroimaging. Implications and directions for future research are discussed. Specifically, this case demonstrates the need for inclusion of neuropsychological assessment in studies of larger cohorts of monozygotic twins with NF-1 and correlation of neuropsychological findings with neuroimaging and postzygotic mutations.
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Affiliation(s)
- Cody Pendergrass
- Graduate School of Professional Psychology, University of Denver, Denver, CO, USA.,Outpatient Behavioral Health Services, Denver Health Medical Center, Denver, CO, USA
| | - Jennifer Peraza
- Outpatient Behavioral Health Services, Denver Health Medical Center, Denver, CO, USA.,Department of Psychiatry, University of Colorado, Aurora, CO, USA
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20
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Abstract
INTRODUCTION Neurofibromatosis type 1 (NF1) is an autosomal dominantly inherited tumor predisposition syndrome with an incidence of one in 3000-4000 individuals with no currently effective therapies. The NF1 gene encodes neurofibromin, which functions as a negative regulator of RAS. NF1 is a chronic multisystem disorder affecting many different tissues. Due to cell-specific complexities of RAS signaling, therapeutic approaches for NF1 will likely have to focus on a particular tissue and manifestation of the disease. Areas covered: We discuss the multisystem nature of NF1 and the signaling pathways affected due to neurofibromin deficiency. We explore the cell-/tissue-specific molecular and cellular consequences of aberrant RAS signaling in NF1 and speculate on their potential as therapeutic targets for the disease. We discuss recent genomic, transcriptomic, and proteomic studies combined with molecular, cellular, and biochemical analyses which have identified several targets for specific NF1 manifestations. We also consider the possibility of patient-specific gene therapy approaches for NF1. Expert opinion: The emergence of NF1 genotype-phenotype correlations, characterization of cell-specific signaling pathways affected in NF1, identification of novel biomarkers, and the development of sophisticated animal models accurately reflecting human pathology will continue to provide opportunities to develop therapeutic approaches to combat this multisystem disorder.
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Affiliation(s)
- James A Walker
- a Center for Genomic Medicine , Massachusetts General Hospital, Harvard Medical School , Boston , MA , USA
| | - Meena Upadhyaya
- b Division of Cancer and Genetics , Cardiff University , Cardiff , UK
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21
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Fabre A, Roman C, Roquelaure B. Somatic mutation, a cause of biliary atresia: A hypothesis. Med Hypotheses 2017; 102:91-93. [PMID: 28478841 DOI: 10.1016/j.mehy.2017.03.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 02/27/2017] [Accepted: 03/08/2017] [Indexed: 02/07/2023]
Abstract
Despite many years of research, the causes of biliary atresia still remain elusive. Infection, immune disorder, toxins or maternal microchimerism have been cited as potential triggers of biliary atresia. This is a rare disease with a stable incidence over the years although with sizeable ethnic variations. This stability suggests that environmental factors have in fact only a slight influence. During the search for etiologies, twin studies have often helped disentangle the genetic from the environmental. For this condition, twin studies have mainly demonstrated a lack of concordance between twins (either monozygotic or dizygotic), ruling out Mendelian, infectious or toxic causes. Indeed, for toxic or infectious embryopathy, the concordance for twins (especially monozygotic) is about 80%. Paradoxically, these data suggest that biliary atresia has neither a genetic nor an environmental cause. One way of severing the Gordian knot is to hypothesize a role for post zygotic somatic mutation, leading to genetic mosaicism (as a cause of biliary atresia). In recent years, post zygotic mutation has been identified as a cause of non-cancerous disease ranging from dysmorphic syndrome to specific organ abnormalities. A potential model for this condition could be post zygotic mutation or copy number variations in genes or regulatory regions, triggering the cascade of events leading to inflammatory and obliterative cholangiopathy. These events could be enhanced by genetic susceptibility explaining the ethnic variations. In these models, the rate of mosaicism in different parts of the liver could explain the success rate of the Kasai procedure. This hypothesis can be tested: as most children with biliary atresia are eligible for the Kasai procedure, genetic material from the liver and ductal plate can be collected easily. If the hypothesis is correct, whole genome sequencing or copy number variation studies at individual cell level should allow to identify the expected low level of genetic mosaicism. Thus, we hypothesize that postzygotic somatic mutation may play a part in the physiopathology of biliary atresia.
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Affiliation(s)
- Alexandre Fabre
- Service de Pédiatrie Multidisciplinaire Hopital de la Timone, APHM, Marseille, France; Aix Marseille Université, INSERM, Génétique Médicale et Génomique Fonctionnelle (GMGF), UMRS 910, Marseille, France.
| | - Céline Roman
- Service de Pédiatrie Multidisciplinaire Hopital de la Timone, APHM, Marseille, France
| | - Bertrand Roquelaure
- Service de Pédiatrie Multidisciplinaire Hopital de la Timone, APHM, Marseille, France
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22
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Sites ER, Smolarek TA, Martin LJ, Viskochil DH, Stevenson DA, Ullrich NJ, Messiaen LM, Schorry EK. Analysis of copy number variants in 11 pairs of monozygotic twins with neurofibromatosis type 1. Am J Med Genet A 2016; 173:647-653. [PMID: 27862945 DOI: 10.1002/ajmg.a.38058] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 10/27/2016] [Indexed: 01/08/2023]
Abstract
Phenotypic variability among individuals with neurofibromatosis type 1 (NF1) has long been a challenge for clinicians and an enigma for researchers. Members of the same family and even identical twins with NF1 often demonstrate variable disease expression. Many mechanisms for this variability have been proposed. We have performed an exploratory study of copy number variants (CNVs) as a possible source of phenotypic variability in NF1. We enrolled 11 pairs of monozygotic (MZ) twins with NF1 and their parents, catalogued their clinical characteristics, and utilized a single nucleotide polymorphism (SNP) microarray to identify CNVs in blood and saliva. The 11 twin pairs showed high concordance for presence and number of café-au-lait spots, cutaneous neurofibromas, IQ, and ADHD. They were more likely to be discordant for optic pathway glioma, plexiform neurofibromas, skeletal manifestations, and malignancy. Microarray analysis identified a total of 81 CNVs meeting our conservative criteria, 37 of which overlap known genes. Of interest, three CNVs were previously unreported. Microarray analysis failed to ascertain any CNV differences within twin pairs, between twins and parents, or between tissues in any one individual. Results of this small pilot study did not demonstrate any de novo CNV events in our MZ twin pairs, nor were de novo CNVs overrepresented in these individuals with NF1. A much larger sample size would be needed to form any conclusions about the role of CNVs in NF1 variable expressivity. Alternative explanations for discordant phenotypes include epigenetic changes, smaller genetic alterations, or environmental factors. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
| | - Teresa A Smolarek
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Lisa J Martin
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - David H Viskochil
- Divison of Medical Genetics, University of Utah, Salt Lake City, Utah
| | - David A Stevenson
- Division of Medical Genetics, Department of Pediatrics, Stanford University, Stanford, California
| | - Nicole J Ullrich
- Department of Neurology, Boston Children's Hospital, Boston, Massachusetts
| | | | - Elizabeth K Schorry
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
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23
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Feasibility and Preliminary Efficacy of an Internet Support Group for Parents of a Child with Neurofibromatosis Type 1: a Pilot Study. J Genet Couns 2016; 26:576-585. [PMID: 27822877 DOI: 10.1007/s10897-016-0031-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 10/03/2016] [Indexed: 12/19/2022]
Abstract
This pilot study investigated the feasibility and preliminary efficacy of an Internet Support Group (ISG) for parents of children with NF1. Eligible parents were recruited by email and completed baseline questionnaires assessing social support, self-efficacy, depression, and anxiety. The ISG involved eight weekly 90-min chat sessions and a discussion forum open 24 h/day for 8 weeks. Follow-up measures were completed immediately post-intervention and 3 months later. Parents from 33 families (29 mothers, 4 fathers) completed baseline measures. Over half of parents (52 %) rated their child's disease severity as mild, 33 % moderate, and 15 % severe. Among 21 parents who completed post-intervention measures, ratings of perceived emotional (p = .0008) and informational (p = .0003) support increased. There were no significant changes in self-efficacy, depression, or anxiety (ps > .05). The mean satisfaction rating was moderately high (7.6/10; range 4-10). Some parents commented that the chat sessions were at inconvenient times, which may have limited participation. Preliminary evidence in this small sample of parents suggests that ISGs may be a feasible and potentially efficacious method of providing support to parents of children with NF1. Having multiple weekly chat sessions held at various days and times may improve accessibility and participation. Clinicians are encouraged to help parents access online support resources.
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24
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Wu J, Liu W, Williams JP, Ratner N. EGFR-Stat3 signalling in nerve glial cells modifies neurofibroma initiation. Oncogene 2016; 36:1669-1677. [PMID: 27748759 DOI: 10.1038/onc.2016.386] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 09/02/2016] [Accepted: 09/04/2016] [Indexed: 02/06/2023]
Abstract
Neurofibromatosis type 1 (NF1) is an inherited disease in which affected patients are predisposed to develop benign Schwann cell (SC) tumours called neurofibromas. In the mouse, loss of Nf1 in the SC lineage causes neurofibroma formation. The tyrosine kinase receptor EGFR is expressed in Schwann cell precursors (SCP), which have been implicated in plexiform neurofibroma initiation. To test if EGFR activity affects neurofibroma initiation, size, and/or number, we studied mice expressing human EGFR in SCs and SCP in the context of mice that form neurofibromas. Neurofibroma number increased in homozygous CNP-hEGFR mice versus heterozygous littermates, and neurofibroma number and size increased when CNP-hEGFR was crossed to Nf1fl/fl;DhhCre mice. Conversely, diminished EGFR signalling in Nf1fl/fl;DhhCre;Wa2/+ mice decreased neurofibroma number. In vivo transplantation verified the correlation between EGFR activity and neurofibroma formation. Mechanistically, expression of CNP-hEGFR increased SCP/neurofibroma-initiating cell self-renewal, a surrogate for tumour initiation, and activated P-Stat3. Further, Il-6 reinforced Jak2/Stat3 activation in SCPs and SCs. These gain- and loss-of function assays show that levels of tyrosine kinase expression in SCPs modify neurofibroma initiation.
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Affiliation(s)
- J Wu
- Division of Experimental Hematology and Cancer Biology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Research Foundation, Cincinnati Children's Hospital, University of Cincinnati, Cincinnati, OH, USA
| | - W Liu
- Division of Experimental Hematology and Cancer Biology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Research Foundation, Cincinnati Children's Hospital, University of Cincinnati, Cincinnati, OH, USA
| | - J P Williams
- Division of Experimental Hematology and Cancer Biology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Research Foundation, Cincinnati Children's Hospital, University of Cincinnati, Cincinnati, OH, USA
| | - N Ratner
- Division of Experimental Hematology and Cancer Biology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Research Foundation, Cincinnati Children's Hospital, University of Cincinnati, Cincinnati, OH, USA
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25
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An Update on Neurofibromatosis Type 1: Not Just Café-au-Lait Spots and Freckling. Part II. Other Skin Manifestations Characteristic of NF1. NF1 and Cancer. ACTAS DERMO-SIFILIOGRAFICAS 2016. [DOI: 10.1016/j.adengl.2016.05.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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26
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Martin S, Wolters PL, Toledo-Tamula MA, Schmitt SN, Baldwin A, Starosta A, Gillespie A, Widemann B. Acceptance and commitment therapy in youth with neurofibromatosis type 1 (NF1) and chronic pain and their parents: A pilot study of feasibility and preliminary efficacy. Am J Med Genet A 2016; 170:1462-70. [PMID: 27021207 PMCID: PMC6675568 DOI: 10.1002/ajmg.a.37623] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 02/26/2016] [Indexed: 11/09/2022]
Abstract
Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder affecting about 1 in 3,500 individuals. Chronic pain is commonly reported among individuals with NF1 and plexiform neurofibroma tumors (PNs). Acceptance and Commitment Therapy (ACT), an empirically supported method for addressing chronic pain, helps individuals re-focus on valued relationships and activities. This pilot study investigated the feasibility and preliminary efficacy of a brief ACT workshop in the NF1 population. Eligible participants included adolescents and young adults (AYA; 12-21 years) with NF1 and chronic pain that interfered with daily functioning and their parents. Patients and parents completed baseline measures of pain interference, pain intensity, functional disability, pain acceptance, depression, and anxiety. Then, AYA and parents participated separately in a 2-day small-group ACT workshop. A telephone booster session occurred 1 month post-intervention. Three-month post-treatment measures were completed by mail. Ten adolescents (4 males; M age = 16.9 years) and seven parents provided baseline and 3-month data. Mean satisfaction with the study was moderate to high (3.9 for patients and 4.6 for parents on a 1-5 scales). Patients and parents reported significant declines in patients' pain interference at 3 months post-treatment. Patient-reported pain intensity significantly declined from baseline to 3 months. Parents reported marginally greater acceptance of their child's pain. No changes emerged in functional ability or mood. Preliminary findings suggest that a brief ACT group intervention is feasible and may help AYA with NF1 and PNs cope with their chronic pain, although larger randomized studies are needed to confirm treatment efficacy. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Staci Martin
- Pediatric Oncology Branch, National Cancer Institute, Montgomery County, Bethesda, Maryland
| | - Pamela L. Wolters
- Pediatric Oncology Branch, National Cancer Institute, Montgomery County, Bethesda, Maryland
| | - Mary Anne Toledo-Tamula
- Clinical Research Directorate/CMRP, Leidos Biomedical Research, Inc., National Laboratory for Cancer Research, Frederick County, Frederick, Maryland
| | - Shawn Nelson Schmitt
- Pediatric Oncology Branch, National Cancer Institute, Montgomery County, Bethesda, Maryland
- Ettenhofer Laboratory for Neurocognitive Research, Uniformed Services University of the Health Sciences, Montgomery County, Bethesda, Maryland
| | - Andrea Baldwin
- Pediatric Oncology Branch, National Cancer Institute, Montgomery County, Bethesda, Maryland
| | - Amy Starosta
- Pediatric Oncology Branch, National Cancer Institute, Montgomery County, Bethesda, Maryland
- University at Albany, State University of New York, Albany County, Albany, New York
| | - Andrea Gillespie
- Pediatric Oncology Branch, National Cancer Institute, Montgomery County, Bethesda, Maryland
| | - Brigitte Widemann
- Pediatric Oncology Branch, National Cancer Institute, Montgomery County, Bethesda, Maryland
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27
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Abstract
Neurofibromatosis I is a common genetic disorder that results in tumor formation, and predisposes individuals to a range of cognitive/behavioral symptoms, including deficits in attention, visuospatial skills, learning, language development, and sleep, and autism spectrum disorder-like traits. The nf1-encoded neurofibromin protein (Nf1) exhibits high conservation, from the common fruit fly, Drosophila melanogaster, to humans. Drosophila provides a powerful platform to investigate the signaling cascades upstream and downstream of Nf1, and the fly model exhibits similar behavioral phenotypes to mammalian models. In order to understand how loss of Nf1 affects motor behavior in flies, we combined traditional activity monitoring with video analysis of grooming behavior. In nf1 mutants, spontaneous grooming was increased up to 7x. This increase in activity was distinct from previously described dopamine-dependent hyperactivity, as dopamine transporter mutants exhibited slightly decreased grooming. Finally, we found that relative grooming frequencies can be compared in standard activity monitors that measure infrared beam breaks, enabling the use of activity monitors as an automated method to screen for grooming phenotypes. Overall, these data suggest that loss of nf1 produces excessive activity that is manifested as increased grooming, providing a platform to dissect the molecular genetics of neurofibromin signaling across neuronal circuits.
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Ikegami D, Igarashi K, Otsuka M, Kuzumaki N, Narita M. [The importance of epigenetic analysis in pain]. Nihon Yakurigaku Zasshi 2016; 147:225-229. [PMID: 27063906 DOI: 10.1254/fpj.147.225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
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Hernández-Martín A, Duat-Rodríguez A. An Update on Neurofibromatosis Type 1: Not Just Café-au-Lait Spots and Freckling. Part II. Other Skin Manifestations Characteristic of NF1. NF1 and Cancer. ACTAS DERMO-SIFILIOGRAFICAS 2016; 107:465-73. [PMID: 26956402 DOI: 10.1016/j.ad.2016.01.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 01/07/2016] [Accepted: 01/17/2016] [Indexed: 12/16/2022] Open
Abstract
Neurofibromatosis type 1 (NF1) is the most common neurocutaneous syndrome and probably the one best known to dermatologists. Although the genetic locus of NF1 was identified on chromosome 17 in 1987, diagnosis of the disease is still based primarily on clinical observations. The 7 diagnostic criteria of the National Institutes of Health, which were established in 1988, include 3 skin manifestations (café-au-lait spots, freckling on flexural areas, and cutaneous neurofibromas). The age at which these diagnostic lesions appear is variable: onset can be late in some patients while others never develop certain symptoms. Definitive diagnosis may therefore be delayed by years. Although the appearance of the characteristic café-au-lait spots and freckling in the early years of childhood are very suggestive of the disease, these signs are not pathognomonic and, in isolation, do not constitute sufficient evidence to establish a definitive diagnosis. Thus, other diagnoses should be considered in patients whose only symptoms are café-au-lait spots and freckling. By contrast, the presence of multiple cutaneous neurofibromas or at least 1 plexiform neurofibroma is a very specific indication of NF1. Identification of the different types of neurofibroma allows us to confirm the diagnosis and initiate appropriate management.
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Affiliation(s)
- A Hernández-Martín
- Servicio de Dermatología Hospital Infantil del Niño Jesús. Madrid, España.
| | - A Duat-Rodríguez
- Servicio de Neurología, Hospital Infantil del Niño Jesús, Madrid, España
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Ejerskov C, Farholt S, Skovby F, Vestergaard E, Haagerup A. Clinical presentations of 23 half-siblings from a mosaic neurofibromatosis type 1 sperm donor. Clin Genet 2015; 89:346-50. [DOI: 10.1111/cge.12600] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2015] [Revised: 04/13/2015] [Accepted: 04/13/2015] [Indexed: 11/28/2022]
Affiliation(s)
- C. Ejerskov
- Centre for Rare Diseases, Department of Paediatrics; Aarhus University Hospital; Aarhus Denmark
| | - S. Farholt
- Centre for Rare Diseases, Department of Paediatrics; Aarhus University Hospital; Aarhus Denmark
| | - F. Skovby
- Centre for Rare Diseases, Department of Clinical Genetics; Copenhagen University Hospital; Copenhagen Denmark
| | - E.M. Vestergaard
- Department of Clinical Genetics; Aarhus University Hospital; Aarhus Denmark
| | - A. Haagerup
- Centre for Rare Diseases, Department of Paediatrics; Aarhus University Hospital; Aarhus Denmark
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Ratner N, Miller SJ. A RASopathy gene commonly mutated in cancer: the neurofibromatosis type 1 tumour suppressor. Nat Rev Cancer 2015; 15:290-301. [PMID: 25877329 PMCID: PMC4822336 DOI: 10.1038/nrc3911] [Citation(s) in RCA: 300] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Neurofibromatosis type 1 (NF1) is a common genetic disorder that predisposes affected individuals to tumours. The NF1 gene encodes a RAS GTPase-activating protein called neurofibromin and is one of several genes that (when mutant) affect RAS-MAPK signalling, causing related diseases collectively known as RASopathies. Several RASopathies, beyond NF1, are cancer predisposition syndromes. Somatic NF1 mutations also occur in 5-10% of human sporadic cancers and may contribute to resistance to therapy. To highlight areas for investigation in RASopathies and sporadic tumours with NF1 mutations, we summarize current knowledge of NF1 disease, the NF1 gene and neurofibromin, neurofibromin signalling pathways and recent developments in NF1 therapeutics.
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Affiliation(s)
- Nancy Ratner
- Division of Experimental Hematology and Cancer Biology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
| | - Shyra J Miller
- Division of Experimental Hematology and Cancer Biology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
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Crawford HA, Barton B, Wilson MJ, Berman Y, McKelvey-Martin VJ, Morrison PJ, North KN. The Impact of Neurofibromatosis Type 1 on the Health and Wellbeing of Australian Adults. J Genet Couns 2015; 24:931-44. [DOI: 10.1007/s10897-015-9829-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Accepted: 02/24/2015] [Indexed: 10/23/2022]
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Gutmann DH. Eliminating barriers to personalized medicine: learning from neurofibromatosis type 1. Neurology 2014; 83:463-71. [PMID: 24975854 DOI: 10.1212/wnl.0000000000000652] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
With the emergence of high-throughput discovery platforms, robust preclinical small-animal models, and efficient clinical trial pipelines, it is becoming possible to envision a time when the treatment of human neurologic diseases will become personalized. The emergence of precision medicine will require the identification of subgroups of patients most likely to respond to specific biologically based therapies. This stratification only becomes possible when the determinants that contribute to disease heterogeneity become more fully elucidated. This review discusses the defining factors that underlie disease heterogeneity relevant to the potential for individualized brain tumor (optic pathway glioma) treatments arising in the common single-gene cancer predisposition syndrome, neurofibromatosis type 1 (NF1). In this regard, NF1 is posited as a model genetic condition to establish a workable paradigm for actualizing precision therapeutics for other neurologic disorders.
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Affiliation(s)
- David H Gutmann
- From the Department of Neurology, Washington University School of Medicine, St. Louis, MO.
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Familial syndromes associated with intracranial tumours: a review. Childs Nerv Syst 2014; 30:47-64. [PMID: 24193148 DOI: 10.1007/s00381-013-2309-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2013] [Accepted: 10/15/2013] [Indexed: 12/15/2022]
Abstract
BACKGROUND Most cancers of the central nervous system (CNS) occur sporadically in the absence of any known underlying familial disorder or multi-systemic syndrome. Several syndromes are associated with CNS malignancies, however, and their recognition has significant implications for patient management and prognosis. Patients with syndrome-associated CNS malignancies often have multiple tumours (either confined to one region or distributed throughout the body), with similar or different histology. OBJECTIVE This review examines syndromes that are strongly associated with CNS cancers: the phakomatosis syndromes, familial syndromes such as Li-Fraumeni and familial polyposis syndromes and dyschondroplasia.
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Does the presence of dystrophic features in patients with type 1 neurofibromatosis and spinal deformities increase the risk of surgery? Spine (Phila Pa 1976) 2013; 38:1595-601. [PMID: 23680833 DOI: 10.1097/brs.0b013e31829a7779] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Retrospective chart and radiographical review. OBJECTIVE To present the demographics of patients with scoliosis and neurofibromatosis type 1 (NF-1), to record the incidence of dystrophic features, and to determine whether the presence of dystrophic features increase the risk of surgery in patients with NF-1 and associated spinal pathology. SUMMARY OF BACKGROUND DATA The most common of the osseous complications of NF-1 is spinal deformity, occurring in 10% to 30% of individuals with NF-1. Many of these patients will eventually require surgery for curve progression, which makes study of demographics and identification of features predicting the need for surgery essential in this patient population. METHODS A retrospective review was performed in patients with NF-1 and spinal deformities, followed in a multidisciplinary neurofibromatosis center. A subset of 56 patients with complete radiographical evaluation was reviewed for identification of risk factors for spine surgery. RESULTS One hundred thirty-one patients from a population of 694 patients with NF-1 (19%) had scoliosis. Mean age at diagnosis of scoliosis was 9 years (range; 1-17 yr). Scoliosis and need for surgery were equally distributed between males and females. In the group of 56 patients, 63% had 3 or more dystrophic features. The presence of 3 or more dystrophic features was the strongest predictor of the need for surgery (odds ratio = 14.34; P < 0.001). Individual features most predictive of need for surgery were the presence of vertebral scalloping (odds ratio = 13.19; P < 0.001) followed by the presence of dural ectasia (odds ratio = 6.38; P = 0.005). Patients with no dystrophic features were unlikely to progress to need for surgery. CONCLUSION Scoliosis and need for surgery were equally distributed between males and females. The presence of 3 or more dystrophic features was highly predictive of the need for surgery, with the most significant individual predictors being vertebral scalloping and dural ectasia. A combination of radiographical and MRI features can be used to predict need for spinal surgery. LEVEL OF EVIDENCE 3.
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Johnson KJ, Hussain I, Williams K, Santens R, Mueller NL, Gutmann DH. Development of an international internet-based neurofibromatosis Type 1 Patient registry. Contemp Clin Trials 2013; 34:305-11. [DOI: 10.1016/j.cct.2012.12.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 11/08/2012] [Accepted: 12/05/2012] [Indexed: 11/29/2022]
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Buchheit T, Van de Ven T, Shaw A. Epigenetics and the transition from acute to chronic pain. PAIN MEDICINE 2012; 13:1474-90. [PMID: 22978429 DOI: 10.1111/j.1526-4637.2012.01488.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
OBJECTIVE The objective of this study was to review the epigenetic modifications involved in the transition from acute to chronic pain and to identify potential targets for the development of novel, individualized pain therapeutics. BACKGROUND Epigenetics is the study of heritable modifications in gene expression and phenotype that do not require a change in genetic sequence to manifest their effects. Environmental toxins, medications, diet, and psychological stresses can alter epigenetic processes such as DNA methylation, histone acetylation, and RNA interference. As epigenetic modifications potentially play an important role in inflammatory cytokine metabolism, steroid responsiveness, and opioid sensitivity, they are likely key factors in the development of chronic pain. Although our knowledge of the human genetic code and disease-associated polymorphisms has grown significantly in the past decade, we have not yet been able to elucidate the mechanisms that lead to the development of persistent pain after nerve injury or surgery. DESIGN This is a focused literature review of epigenetic science and its relationship to chronic pain. RESULTS Significant laboratory and clinical data support the notion that epigenetic modifications are affected by the environment and lead to differential gene expression. Similar to mechanisms involved in the development of cancer, neurodegenerative disease, and inflammatory disorders, the literature endorses an important potential role for epigenetics in chronic pain. CONCLUSIONS Epigenetic analysis may identify mechanisms critical to the development of chronic pain after injury, and may provide new pathways and target mechanisms for future drug development and individualized medicine.
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Affiliation(s)
- Thomas Buchheit
- Department of Anesthesiology, Duke University Medical Center, Durham VA Medical Center, Durham, NC 27710, USA.
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Houlden H, Singleton AB. The genetics and neuropathology of Parkinson's disease. Acta Neuropathol 2012; 124:325-38. [PMID: 22806825 PMCID: PMC3589971 DOI: 10.1007/s00401-012-1013-5] [Citation(s) in RCA: 228] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Revised: 06/22/2012] [Accepted: 07/01/2012] [Indexed: 10/28/2022]
Abstract
There has been tremendous progress toward understanding the genetic basis of Parkinson's disease and related movement disorders. We summarize the genetic, clinical and pathological findings of autosomal dominant disease linked to mutations in SNCA, LRRK2, ATXN2, ATXN3, MAPT, GCH1, DCTN1 and VPS35. We then discuss the identification of mutations in PARK2, PARK7, PINK1, ATP13A2, FBXO7, PANK2 and PLA2G6 genes. In particular we discuss the clinical and pathological characterization of these forms of disease, where neuropathology has been important in the likely coalescence of pathways highly relevant to typical PD. In addition to the identification of the causes of monogenic forms of PD, significant progress has been made in defining genetic risk loci for PD; we discuss these here, including both risk variants at LRRK2 and GBA, in addition to discussing the results of recent genome-wide association studies and their implications for PD. Finally, we discuss the likely path of genetic discovery in PD over the coming period and the implications of these findings from a clinical and etiological perspective.
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Affiliation(s)
- Henry Houlden
- Molecular Neuroscience Department, UCL Institute of Neurology and The National Hospital for Neurology and Neurosurgery, University College London, Queen Square, London, UK
| | - Andrew B. Singleton
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD, USA,
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Abstract
NF1 (neurofibromatosis type I) is a common genetic disease that affects one in 3500 individuals. The disease is completely penetrant but shows variable phenotypic expression in patients. NF1 is a large gene, and its pre-mRNA undergoes alternative splicing. The NF1 protein, neurofibromin, is involved in diverse signalling cascades. One of the best characterized functions of NF1 is its function as a Ras-GAP (GTPase-activating protein). NF1 exon 23a is an alternative exon that lies within the GAP-related domain of neurofibromin. This exon is predominantly included in most tissues, and it is skipped in CNS (central nervous system) neurons. The isoform in which exon 23a is skipped has 10 times higher Ras-GAP activity than the isoform in which exon 23a is included. Exon 23a inclusion is tightly regulated by at least three different families of RNA-binding proteins: CELF {CUG-BP (cytosine-uridine-guanine-binding protein) and ETR-3 [ELAV (embryonic lethal abnormal vision)-type RNA-binding protein]-like factor}, Hu and TIA-1 (T-cell intracellular antigen 1)/TIAR (T-cell intracellular antigen 1-related protein). The CELF and Hu proteins promote exon 23a skipping, while the TIA-1/TIAR proteins promote its inclusion. The widespread clinical variability that is observed among NF1 patients cannot be explained by NF1 mutations alone and it is believed that modifier genes may have a role in the variability. We suggest that the regulation of alternative splicing may act as a modifier to contribute to the variable expression in NF1 patients.
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