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Gooley S, Perucca P, Tubb C, Hildebrand MS, Berkovic SF. Somatic mosaicism in focal epilepsies. Curr Opin Neurol 2024; 37:105-114. [PMID: 38235675 DOI: 10.1097/wco.0000000000001244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
PURPOSE OF REVIEW Over the past decade, it has become clear that brain somatic mosaicism is an important contributor to many focal epilepsies. The number of cases and the range of underlying pathologies with somatic mosaicism are rapidly increasing. This growth in somatic variant discovery is revealing dysfunction in distinct molecular pathways in different focal epilepsies. RECENT FINDINGS We briefly summarize the current diagnostic yield of pathogenic somatic variants across all types of focal epilepsy where somatic mosaicism has been implicated and outline the specific molecular pathways affected by these variants. We will highlight the recent findings that have increased diagnostic yields such as the discovery of pathogenic somatic variants in novel genes, and new techniques that allow the discovery of somatic variants at much lower variant allele fractions. SUMMARY A major focus will be on the emerging evidence that somatic mosaicism may contribute to some of the more common focal epilepsies such as temporal lobe epilepsy with hippocampal sclerosis, which could lead to it being re-conceptualized as a genetic disorder.
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Affiliation(s)
- Samuel Gooley
- Epilepsy Research Centre, Department of Medicine, University of Melbourne
- Bladin-Berkovic Comprehensive Epilepsy Program, Department of Neurology, Austin Health, Heidelberg
| | - Piero Perucca
- Epilepsy Research Centre, Department of Medicine, University of Melbourne
- Bladin-Berkovic Comprehensive Epilepsy Program, Department of Neurology, Austin Health, Heidelberg
- Department of Neuroscience, Central Clinical School, Monash University
- Department of Neurology, Alfred Health, Melbourne
- Department of Neurology, The Royal Melbourne Hospital
| | - Caitlin Tubb
- Epilepsy Research Centre, Department of Medicine, University of Melbourne
| | - Michael S Hildebrand
- Epilepsy Research Centre, Department of Medicine, University of Melbourne
- Neuroscience Group, Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, University of Melbourne
- Bladin-Berkovic Comprehensive Epilepsy Program, Department of Neurology, Austin Health, Heidelberg
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Ali S, Abrar M, Hussain I, Batool F, Raza RZ, Khatoon H, Zoia M, Visel A, Shubin NH, Osterwalder M, Abbasi AA. Identification of ancestral gnathostome Gli3 enhancers with activity in mammals. Dev Growth Differ 2024; 66:75-88. [PMID: 37925606 PMCID: PMC10841732 DOI: 10.1111/dgd.12901] [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: 04/28/2023] [Revised: 09/01/2023] [Accepted: 10/23/2023] [Indexed: 11/06/2023]
Abstract
Abnormal expression of the transcriptional regulator and hedgehog (Hh) signaling pathway effector Gli3 is known to trigger congenital disease, most frequently affecting the central nervous system (CNS) and the limbs. Accurate delineation of the genomic cis-regulatory landscape controlling Gli3 transcription during embryonic development is critical for the interpretation of noncoding variants associated with congenital defects. Here, we employed a comparative genomic analysis on fish species with a slow rate of molecular evolution to identify seven previously unknown conserved noncoding elements (CNEs) in Gli3 intronic intervals (CNE15-21). Transgenic assays in zebrafish revealed that most of these elements drive activities in Gli3 expressing tissues, predominantly the fins, CNS, and the heart. Intersection of these CNEs with human disease associated SNPs identified CNE15 as a putative mammalian craniofacial enhancer, with conserved activity in vertebrates and potentially affected by mutation associated with human craniofacial morphology. Finally, comparative functional dissection of an appendage-specific CNE conserved in slowly evolving fish (elephant shark), but not in teleost (CNE14/hs1586) indicates co-option of limb specificity from other tissues prior to the divergence of amniotes and lobe-finned fish. These results uncover a novel subset of intronic Gli3 enhancers that arose in the common ancestor of gnathostomes and whose sequence components were likely gradually modified in other species during the process of evolutionary diversification.
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Affiliation(s)
- Shahid Ali
- National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Faculty of Biological Sciences, Quaid-i-Azam University, 45320, Islamabad Pakistan
- Department of Organismal Biology and Anatomy, The University of Chicago, Chicago, IL 60637, USA
| | - Muhammad Abrar
- National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Faculty of Biological Sciences, Quaid-i-Azam University, 45320, Islamabad Pakistan
| | - Irfan Hussain
- National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Faculty of Biological Sciences, Quaid-i-Azam University, 45320, Islamabad Pakistan
| | - Fatima Batool
- National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Faculty of Biological Sciences, Quaid-i-Azam University, 45320, Islamabad Pakistan
| | - Rabail Zehra Raza
- Department of Biological Sciences, Faculty of Multidisciplinary Studies, National University of Medical Sciences Rawalpindi, Pakistan
| | - Hizran Khatoon
- National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Faculty of Biological Sciences, Quaid-i-Azam University, 45320, Islamabad Pakistan
| | - Matteo Zoia
- Department for Biomedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Axel Visel
- Environmental Genomics and System Biology Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
- U.S. Department of Energy Joint Genome Institute, 1 Cyclotron Road, Berkeley, CA 94720, USA
- School of Natural Sciences, University of California, Merced, Merced, CA 95343, USA
| | - Neil H. Shubin
- Department of Organismal Biology and Anatomy, The University of Chicago, Chicago, IL 60637, USA
| | - Marco Osterwalder
- Department for Biomedical Research (DBMR), University of Bern, Bern, Switzerland
- Department of Cardiology, Bern University Hospital, Bern, Switzerland
| | - Amir Ali Abbasi
- National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Faculty of Biological Sciences, Quaid-i-Azam University, 45320, Islamabad Pakistan
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Green TE, Fujita A, Ghaderi N, Heinzen EL, Matsumoto N, Klein KM, Berkovic SF, Hildebrand MS. Brain mosaicism of hedgehog signalling and other cilia genes in hypothalamic hamartoma. Neurobiol Dis 2023; 185:106261. [PMID: 37579995 DOI: 10.1016/j.nbd.2023.106261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 08/02/2023] [Accepted: 08/11/2023] [Indexed: 08/16/2023] Open
Abstract
Hypothalamic hamartoma (HH) is a rare benign developmental brain lesion commonly associated with a well characterized epilepsy phenotype. Most individuals with HH are non-syndromic without additional developmental anomalies nor a family history of disease. Nonetheless, HH is a feature of Pallister-Hall (PHS) and Oro-Facial-Digital Type VI (OFD VI) syndromes, both characterized by additional developmental anomalies. Initial genetic of analysis HH began with syndromic HH, where germline inherited or de novo variants in GLI3, encoding a central transcription factor in the sonic hedgehog (Shh) signalling pathway, were identified in most individuals with PHS. Following these discoveries in syndromic HH, the hypothesis that post-zygotic mosaicism in related genes may underly non-syndromic HH was tested. We discuss the identified mosaic variants within individuals with non-syndromic HH, review the analytical methodologies and diagnostic yields, and explore understanding of the functional role of the implicated genes with respect to Shh signalling, and cilia development and function. We also outline future challenges in studying non-syndromic HH and suggest potential novel strategies to interrogate brain mosaicism in HH.
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Affiliation(s)
- Timothy E Green
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, Victoria 3084, Australia
| | - Atsushi Fujita
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Navid Ghaderi
- Departments of Clinical Neurosciences, Medical Genetics and Community Health Sciences, Hotchkiss Brain Institute & Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Canada
| | - Erin L Heinzen
- Eshelman School of Pharmacy, Division of Pharmacotherapy and Experimental Therapeutics, Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
| | - Karl Martin Klein
- Departments of Clinical Neurosciences, Medical Genetics and Community Health Sciences, Hotchkiss Brain Institute & Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Canada; Epilepsy Center Frankfurt Rhine-Main and Department of Neurology, Goethe University and University Hospital Frankfurt, Frankfurt am Main, Germany; LOEWE Center for Personalized Translational Epilepsy Research (CePTER), Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, Victoria 3084, Australia
| | - Michael S Hildebrand
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, Victoria 3084, Australia; Murdoch Children's Research Institute, The Royal Children's Hospital, Parkville, Victoria, Australia.
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D'Gama AM, Poduri A. Brain somatic mosaicism in epilepsy: Bringing results Back to the clinic. Neurobiol Dis 2023; 181:106104. [PMID: 36972791 DOI: 10.1016/j.nbd.2023.106104] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 03/22/2023] [Accepted: 03/23/2023] [Indexed: 03/28/2023] Open
Abstract
Over the past decade, there has been tremendous progress in understanding brain somatic mosaicism in epilepsy in the research setting. Access to resected brain tissue samples from patients with medically refractory epilepsy undergoing epilepsy surgery has been key to making these discoveries. In this review, we discuss the gap between making discoveries in the research setting and bringing results back to the clinical setting. Current clinical genetic testing mainly uses clinically accessible tissue samples, like blood and saliva, and can detect inherited and de novo germline variants and potentially non-brain-limited mosaic variants that have resulted from post-zygotic mutation (also called "somatic mutations"). Methods developed in the research setting to detect brain-limited mosaic variants using brain tissue samples need to be further translated and validated in the clinical setting, which will allow post-resection brain tissue genetic diagnoses. However, obtaining a genetic diagnosis after surgery for refractory focal epilepsy, when brain tissue samples are available, is arguably "too late" to guide precision management. Emerging methods using cerebrospinal fluid (CSF) and subdural electroencephalogram (SEEG) depth electrodes hold promise for establishing genetic diagnoses pre-resection without the need for actual brain tissue. In parallel, development of curation rules for interpreting the pathogenicity of mosaic variants, which have unique considerations compared to germline variants, will assist clinically accredited laboratories and epilepsy geneticists in making genetic diagnoses. Returning results of brain-limited mosaic variants to patients and their families will end their diagnostic odyssey and advance epilepsy precision management.
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Green TE, Motelow JE, Bennett MF, Ye Z, Bennett CA, Griffin NG, Damiano JA, Leventer RJ, Freeman JL, Harvey AS, Lockhart PJ, Sadleir LG, Boys A, Scheffer IE, Major H, Darbro BW, Bahlo M, Goldstein DB, Kerrigan JF, Heinzen EL, Berkovic SF, Hildebrand MS. Sporadic hypothalamic hamartoma is a ciliopathy with somatic and bi-allelic contributions. Hum Mol Genet 2022; 31:2307-2316. [PMID: 35137044 PMCID: PMC9307310 DOI: 10.1093/hmg/ddab366] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 12/02/2021] [Accepted: 12/15/2021] [Indexed: 11/13/2022] Open
Abstract
Hypothalamic hamartoma with gelastic seizures is a well-established cause of drug-resistant epilepsy in early life. The development of novel surgical techniques has permitted the genomic interrogation of hypothalamic hamartoma tissue. This has revealed causative mosaic variants within GLI3, OFD1 and other key regulators of the sonic-hedgehog pathway in a minority of cases. Sonic-hedgehog signalling proteins localize to the cellular organelle primary cilia. We therefore explored the hypothesis that cilia gene variants may underlie hitherto unsolved cases of sporadic hypothalamic hamartoma. We performed high-depth exome sequencing and chromosomal microarray on surgically resected hypothalamic hamartoma tissue and paired leukocyte-derived DNA from 27 patients. We searched for both germline and somatic variants under both dominant and bi-allelic genetic models. In hamartoma-derived DNA of seven patients we identified bi-allelic (one germline, one somatic) variants within one of four cilia genes-DYNC2I1, DYNC2H1, IFT140 or SMO. In eight patients, we identified single somatic variants in the previously established hypothalamic hamartoma disease genes GLI3 or OFD1. Overall, we established a plausible molecular cause for 15/27 (56%) patients. Here, we expand the genetic architecture beyond single variants within dominant disease genes that cause sporadic hypothalamic hamartoma to bi-allelic (one germline/one somatic) variants, implicate three novel cilia genes and reconceptualize the disorder as a ciliopathy.
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Affiliation(s)
- Timothy E Green
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia
| | - Joshua E Motelow
- Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA
| | - Mark F Bennett
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Zimeng Ye
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia
| | - Caitlin A Bennett
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia
| | - Nicole G Griffin
- Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA
| | - John A Damiano
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia
| | - Richard J Leventer
- Department of Neurology, The Royal Children’s Hospital, Parkville, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Parkville, VIC 3052, Australia
- Murdoch Children’s Research Institute, The Royal Children’s Hospital, Parkville, VIC 3052, Australia
| | - Jeremy L Freeman
- Department of Neurology, The Royal Children’s Hospital, Parkville, VIC 3052, Australia
- Murdoch Children’s Research Institute, The Royal Children’s Hospital, Parkville, VIC 3052, Australia
| | - A Simon Harvey
- Department of Neurology, The Royal Children’s Hospital, Parkville, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Parkville, VIC 3052, Australia
- Murdoch Children’s Research Institute, The Royal Children’s Hospital, Parkville, VIC 3052, Australia
| | - Paul J Lockhart
- Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Parkville, VIC 3052, Australia
- Murdoch Children’s Research Institute, The Royal Children’s Hospital, Parkville, VIC 3052, Australia
| | - Lynette G Sadleir
- Department of Paediatrics and Child Health, University of Otago, Wellington 6242, New Zealand
| | - Amber Boys
- Victorian Clinical Genetics Services, Parkville, VIC 3052, Australia
| | - Ingrid E Scheffer
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia
- Department of Neurology, The Royal Children’s Hospital, Parkville, VIC 3052, Australia
- Murdoch Children’s Research Institute, The Royal Children’s Hospital, Parkville, VIC 3052, Australia
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC 3052, Australia
| | - Heather Major
- Department of Pediatrics, The University of Iowa, Iowa City, IA 52246, USA
| | - Benjamin W Darbro
- Department of Pediatrics, The University of Iowa, Iowa City, IA 52246, USA
| | - Melanie Bahlo
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - David B Goldstein
- Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA
- Department of Genetics and Development, Columbia University, New York, NY 10032, USA
| | - John F Kerrigan
- Division of Pediatric Neurology, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ 85013, USA
| | - Erin L Heinzen
- Eshelman School of Pharmacy, Division of Pharmacotherapy and Experimental Therapeutics, and Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia
| | - Michael S Hildebrand
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia
- Murdoch Children’s Research Institute, The Royal Children’s Hospital, Parkville, VIC 3052, Australia
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Liang Y, Liu H, Gao Z, Li Q, Li G, Zhao J, Wang X. Ocular phenotype related SNP analysis in Southern Han Chinese population from Guangdong province. Gene 2022; 826:146458. [PMID: 35358651 DOI: 10.1016/j.gene.2022.146458] [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: 12/06/2021] [Revised: 03/23/2022] [Accepted: 03/25/2022] [Indexed: 11/15/2022]
Abstract
Ocular phenotype is recognizable among Asians, including eyelid fold, fissure inclination, and canthal index. Here we screened 27 facial phenotype-associated SNPs and reported a preliminary study in 246 Chinese individuals of Han origin in Guangdong province. Results showed that rs17760296 could explain 6.2% of the eyelid fold variation and double eyelids were more likely to appear when one's genotype was TT. With respect to the canthal index, rs4791774 and rs642961 were significantly associated with it. However, no individual SNP was associated with fissure inclination. We further constructed two models to predict eyelid fold and canthal index and evaluated them with receiver operating characteristic (ROC) curves and support vector machine (SVM) regression, respectively. The models showed a moderate-to-high predictive capacity (AUC = 0.75, sensitivity = 76%, and specificity = 72%) for the eyelid fold while a mild performance (R2 = 0.1074, MSE = 0.0005, P-value = 0.024) for the canthal index. In conclusion, our study indicates that rs17760296 could be selected into the facial phenotype prediction system for the Southern Han Chinese population. More SNPs are encouraged to improve the prediction accuracy of the canthal index besides rs4791774 and rs642961.
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Affiliation(s)
- Yimeng Liang
- Faculty of Forensic Medicine, Zhongshan School of Medicine, Sun Yat-Sen University & Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan 2nd Road 74, Yuexiu District, Guangzhou, PR China
| | - Heming Liu
- Department of Physiology, Zhongshan School of Medicine, Sun Yat-Sen University, Zhongshan 2nd Road 74, Yuexiu District, Guangzhou, PR China
| | - Zhenjie Gao
- Faculty of Forensic Medicine, Zhongshan School of Medicine, Sun Yat-Sen University & Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan 2nd Road 74, Yuexiu District, Guangzhou, PR China
| | - Qi Li
- Faculty of Forensic Medicine, Zhongshan School of Medicine, Sun Yat-Sen University & Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan 2nd Road 74, Yuexiu District, Guangzhou, PR China
| | - Guoran Li
- Faculty of Forensic Medicine, Zhongshan School of Medicine, Sun Yat-Sen University & Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan 2nd Road 74, Yuexiu District, Guangzhou, PR China
| | - Jian Zhao
- Faculty of Forensic Medicine, Zhongshan School of Medicine, Sun Yat-Sen University & Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan 2nd Road 74, Yuexiu District, Guangzhou, PR China; Guangzhou Forensic Science Institute & Key Laboratory of Forensic Pathology, Ministry of Public Security, Baiyun Avenue 1708, Baiyun District, Guangzhou, PR China.
| | - Xiaoguang Wang
- Faculty of Forensic Medicine, Zhongshan School of Medicine, Sun Yat-Sen University & Guangdong Province Translational Forensic Medicine Engineering Technology Research Center, Zhongshan 2nd Road 74, Yuexiu District, Guangzhou, PR China.
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Savateev AN, Golanov AV, Saushev DA, Osinov IK, Kostyuchenko VV, Dalechina AV, Melikian AG, Vlasov PA, Mazerkina NA, Makashova ES. [Stereotactic radiosurgery for epilepsy related to hypothalamic hamartoma]. ZHURNAL VOPROSY NEIROKHIRURGII IMENI N. N. BURDENKO 2022; 86:14-24. [PMID: 35942833 DOI: 10.17116/neiro20228604114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
UNLABELLED Hypothalamic hamartoma (HH) is a dysplastic lesion fused with hypothalamus and followed by epilepsy, precocious puberty and behavioral disorders. Up to 50% of patients become free of seizures after surgery, but various complications occur in 1/4 of cases. Radiofrequency thermocoagulation, laser interstitial thermal therapy and stereotactic radiosurgery (SRS) are alternative treatment options. OBJECTIVE To define the indications for SRS in patients with HH and to clarify the irradiation parameters. MATERIAL AND METHODS Twenty-two patients with HH and epilepsy underwent SRS at the Moscow Gamma-knife Center. A retrospective analysis included 19 patients with sufficient follow-up data. Median age of patients was 11.5 years (range 1.3-25.8). The diameter of irradiated HHs ranged between 5.5 and 40.9 mm. In 8 (36%) cases, the volume of hamartoma exceeded 3 cm3. Mean prescribed dose was 18±2.0 Gy, mean prescribed isodose - 48±4.2%. Median follow-up period was 14.8 months (range 3.4 - 96.1). RESULTS Three (15.8%) patients were free of seizures. One patient (5.3%) improved dramatically after treatment with compete resolution of generalized seizures and experienced only rare emotional seizures (Engel IB). Eleven (57.8%) patients reported lower incidence of seizures. Severity and incidence of seizures were the same in 4 patients (21.1%). The best results were achieved in mean target dose over 20-22 Gy, minimal target dose over 7-10 Gy, covering by the prescribed dose of at least 70-80% of hamartoma volume, as well as in patients with the prescribed dose of 12 Gy delivered to almost entire volume of tumor. None patient had any complications after SRS. CONCLUSION SRS is safe regarding neurological, endocrine or visual disturbances. Careful patient selection for SRS makes it an effective option for HH-related epilepsy. The best candidates for SRS are children with seizures aged over 1 year, hamartoma <3 cm3 and area of fusion with hypothalamus <150 mm2.
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Affiliation(s)
| | - A V Golanov
- Burdenko Neurosurgical Center, Moscow, Russia
| | | | - I K Osinov
- Moscow Gamma-knife Center, Moscow, Russia
| | | | | | | | - P A Vlasov
- Burdenko Neurosurgical Center, Moscow, Russia
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Heinzen EL. Somatic variants in epilepsy - advancing gene discovery and disease mechanisms. Curr Opin Genet Dev 2020; 65:1-7. [PMID: 32422520 DOI: 10.1016/j.gde.2020.04.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 04/15/2020] [Indexed: 01/03/2023]
Abstract
In the past ten years, there has been increasing recognition that cells can acquire genetic variants during cortical development that can give rise to brain malformations as well as nonlesional focal epilepsy. These often brain tissue-specific, de novo variants can result in highly variable phenotypes based on the burden of a variant in specific tissues and cells. By discovering these variants, shared pathophysiological mechanisms are being revealed between clinically distinct disorders. Beyond informing disease mechanisms, mosaic variants also offer a powerful research tool to trace cellular lineages, to study the roles of specialized cell types in disease presentation, and to establish the cell-type specific genomic consequences of a variant.
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Affiliation(s)
- Erin L Heinzen
- Eshelman School of Pharmacy, Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina, Chapel Hill, NC, United States; Department of Genetics, School of Medicine, University of North Carolina, Chapel Hill, NC, United States.
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9
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Matissek SJ, Elsawa SF. GLI3: a mediator of genetic diseases, development and cancer. Cell Commun Signal 2020; 18:54. [PMID: 32245491 PMCID: PMC7119169 DOI: 10.1186/s12964-020-00540-x] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 02/27/2020] [Indexed: 02/07/2023] Open
Abstract
The transcription factor GLI3 is a member of the Hedgehog (Hh/HH) signaling pathway that can exist as a full length (Gli3-FL/GLI3-FL) or repressor (Gli3-R/GLI3-R) form. In response to HH activation, GLI3-FL regulates HH genes by targeting the GLI1 promoter. In the absence of HH signaling, GLI3 is phosphorylated leading to its partial degradation and the generation of GLI3-R which represses HH functions. GLI3 is also involved in tissue development, immune cell development and cancer. The absence of Gli3 in mice impaired brain and lung development and GLI3 mutations in humans are the cause of Greig cephalopolysyndactyly (GCPS) and Pallister Hall syndromes (PHS). In the immune system GLI3 regulates B, T and NK-cells and may be involved in LPS-TLR4 signaling. In addition, GLI3 was found to be upregulated in multiple cancers and was found to positively regulate cancerous behavior such as anchorage-independent growth, angiogenesis, proliferation and migration with the exception in acute myeloid leukemia (AML) and medulloblastoma where GLI plays an anti-cancerous role. Finally, GLI3 is a target of microRNA. Here, we will review the biological significance of GLI3 and discuss gaps in our understanding of this molecule. Video Abstract.
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Affiliation(s)
- Stephan J. Matissek
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, 46 College Rd Rudman 291, Durham, NH 03824 USA
| | - Sherine F. Elsawa
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, 46 College Rd Rudman 291, Durham, NH 03824 USA
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10
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Ye Z, McQuillan L, Poduri A, Green TE, Matsumoto N, Mefford HC, Scheffer IE, Berkovic SF, Hildebrand MS. Somatic mutation: The hidden genetics of brain malformations and focal epilepsies. Epilepsy Res 2019; 155:106161. [PMID: 31295639 DOI: 10.1016/j.eplepsyres.2019.106161] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 06/27/2019] [Accepted: 07/01/2019] [Indexed: 01/12/2023]
Abstract
Over the past decade there has been a substantial increase in genetic studies of brain malformations, fueled by the availability of improved technologies to study surgical tissue to address the hypothesis that focal lesions arise from focal, post-zygotic genetic disruptions. Traditional genetic studies of patients with malformations utilized leukocyte-derived DNA to search for germline variants, which are inherited or arise de novo in parental gametes. Recent studies have demonstrated somatic variants that arise post-zygotically also underlie brain malformations, and that somatic mutation explains a larger proportion of focal malformations than previously thought. We now know from studies of non-diseased individuals that somatic variation occurs routinely during cell division, including during early brain development when the rapid proliferation of neuronal precursor cells provides the ideal environment for somatic mutation to occur and somatic variants to accumulate. When confined to brain, pathogenic variants contribute to the "hidden genetics" of neurological diseases. With burgeoning novel high-throughput genetic technologies, somatic genetic variations are increasingly being recognized. Here we discuss accumulating evidence for the presence of somatic variants in normal brain tissue, review our current understanding of somatic variants in brain malformations associated with lesional epilepsy, and provide strategies to identify the potential contribution of somatic mutation to non-lesional epilepsies. We also discuss technologies that may improve detection of somatic variants in the future in these and other neurological conditions.
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Affiliation(s)
- Zimeng Ye
- Department of Medicine (Austin Hospital), University of Melbourne, Heidelberg, Victoria, Australia
| | - Lara McQuillan
- Department of Medicine (Austin Hospital), University of Melbourne, Heidelberg, Victoria, Australia
| | - Annapurna Poduri
- Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, Boston, MA, United States
| | - Timothy E Green
- Department of Medicine (Austin Hospital), University of Melbourne, Heidelberg, Victoria, Australia
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Heather C Mefford
- Division of Genetic Medicine, Department of Pediatrics, University of Washington and Seattle Children's Hospital, Seattle, WA, United States
| | - Ingrid E Scheffer
- Department of Medicine (Austin Hospital), University of Melbourne, Heidelberg, Victoria, Australia; Department of Pediatrics, University of Melbourne, Royal Children's Hospital, Parkville, Victoria, Australia; Department of Neurology, Royal Children's Hospital, Parkville, Victoria, Australia; Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Samuel F Berkovic
- Department of Medicine (Austin Hospital), University of Melbourne, Heidelberg, Victoria, Australia
| | - Michael S Hildebrand
- Department of Medicine (Austin Hospital), University of Melbourne, Heidelberg, Victoria, Australia; Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia.
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11
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Corman TS, Bergendahl SE, Epstein DJ. Distinct temporal requirements for Sonic hedgehog signaling in development of the tuberal hypothalamus. Development 2018; 145:dev.167379. [PMID: 30291164 DOI: 10.1242/dev.167379] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 09/20/2018] [Indexed: 12/14/2022]
Abstract
Sonic hedgehog (Shh) plays well characterized roles in brain and spinal cord development, but its functions in the hypothalamus have been more difficult to elucidate owing to the complex neuroanatomy of this brain area. Here, we use fate mapping and conditional deletion models in mice to define requirements for dynamic Shh activity at distinct developmental stages in the tuberal hypothalamus, a brain region with important homeostatic functions. At early time points, Shh signaling regulates dorsoventral patterning, neurogenesis and the size of the ventral midline. Fate-mapping experiments demonstrate that Shh-expressing and -responsive progenitors contribute to distinct neuronal subtypes, accounting for some of the cellular heterogeneity in tuberal hypothalamic nuclei. Conditional deletion of the hedgehog transducer smoothened (Smo), after dorsoventral patterning has been established, reveals that Shh signaling is necessary to maintain proliferation and progenitor identity during peak periods of hypothalamic neurogenesis. We also find that mosaic disruption of Smo causes a non-cell autonomous gain in Shh signaling activity in neighboring wild-type cells, suggesting a mechanism for the pathogenesis of hypothalamic hamartomas, benign tumors that form during hypothalamic development.
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Affiliation(s)
- Tanya S Corman
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6145, USA
| | - Solsire E Bergendahl
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6145, USA
| | - Douglas J Epstein
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6145, USA
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12
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Kerrigan JF, Parsons A, Tsang C, Simeone K, Coons S, Wu J. Hypothalamic hamartoma: Neuropathology and epileptogenesis. Epilepsia 2017; 58 Suppl 2:22-31. [DOI: 10.1111/epi.13752] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/09/2016] [Indexed: 01/06/2023]
Affiliation(s)
- John F. Kerrigan
- Hypothalamic Hamartoma Program and Pediatric Neurology Division; Barrow Neurological Institute at Phoenix Children's Hospital; Phoenix Children's Hospital; Phoenix Arizona U.S.A
- Hypothalamic Hamartoma Tissue Research Laboratory; Barrow Neurological Institute; St. Joseph's Hospital and Medical Center; Phoenix Arizona U.S.A
| | - Angela Parsons
- Hypothalamic Hamartoma Tissue Research Laboratory; Barrow Neurological Institute; St. Joseph's Hospital and Medical Center; Phoenix Arizona U.S.A
| | - Candy Tsang
- Hypothalamic Hamartoma Tissue Research Laboratory; Barrow Neurological Institute; St. Joseph's Hospital and Medical Center; Phoenix Arizona U.S.A
| | - Kristina Simeone
- Department of Pharmacology; Creighton University School of Medicine; Omaha Nebraska U.S.A
| | - Stephen Coons
- Division of Neuropathology; Barrow Neurological Institute; St. Joseph's Hospital and Medical Center; Phoenix Arizona U.S.A
| | - Jie Wu
- Hypothalamic Hamartoma Program and Division of Neurology; Barrow Neurological Institute; St. Joseph's Hospital and Medical Center; Phoenix Arizona U.S.A
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13
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Wang B, Ma J. The diagnosis and management of hypothalamic hamartomas in children. Chin Neurosurg J 2016. [DOI: 10.1186/s41016-016-0047-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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14
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Mutations of the Sonic Hedgehog Pathway Underlie Hypothalamic Hamartoma with Gelastic Epilepsy. Am J Hum Genet 2016; 99:423-9. [PMID: 27453577 DOI: 10.1016/j.ajhg.2016.05.031] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 05/26/2016] [Indexed: 01/16/2023] Open
Abstract
Hypothalamic hamartoma (HH) with gelastic epilepsy is a well-recognized drug-resistant epilepsy syndrome of early life.(1) Surgical resection allows limited access to the small deep-seated lesions that cause the disease. Here, we report the results of a search for somatic mutations in paired hamartoma- and leukocyte-derived DNA samples from 38 individuals which we conducted by using whole-exome sequencing (WES), chromosomal microarray (CMA), and targeted resequencing (TRS) of candidate genes. Somatic mutations were identified in genes involving regulation of the sonic hedgehog (Shh) pathway in 14/38 individuals (37%). Three individuals had somatic mutations in PRKACA, which encodes a cAMP-dependent protein kinase that acts as a repressor protein in the Shh pathway, and four subjects had somatic mutations in GLI3, an Shh pathway gene associated with HH. In seven other individuals, we identified two recurrent and three single brain-tissue-specific, large copy-number or loss-of-heterozygosity (LOH) variants involving multiple Shh genes, as well as other genes without an obvious biological link to the Shh pathway. The Shh pathway genes in these large somatic lesions include the ligand itself (SHH and IHH), the receptor SMO, and several other Shh downstream pathway members, including CREBBP and GLI2. Taken together, our data implicate perturbation of the Shh pathway in at least 37% of individuals with the HH epilepsy syndrome, consistent with the concept of a developmental pathway brain disease.
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15
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Saitsu H, Sonoda M, Higashijima T, Shirozu H, Masuda H, Tohyama J, Kato M, Nakashima M, Tsurusaki Y, Mizuguchi T, Miyatake S, Miyake N, Kameyama S, Matsumoto N. Somatic mutations in GLI3 and OFD1 involved in sonic hedgehog signaling cause hypothalamic hamartoma. Ann Clin Transl Neurol 2016; 3:356-65. [PMID: 27231705 PMCID: PMC4863748 DOI: 10.1002/acn3.300] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 02/29/2016] [Indexed: 01/14/2023] Open
Abstract
Objective Hypothalamic hamartoma (HH) is a congenital anomalous brain tumor. Although most HHs are found without any other systemic features, HH is observed in syndromic disorders such as Pallister–Hall syndrome (PHS) and oral‐facial‐digital syndrome (OFD). Here, we explore the possible involvement of somatic mutations in HH. Methods We analyzed paired blood and hamartoma samples from 18 individuals, including three with digital anomalies, by whole‐exome sequencing. Detected somatic mutations were validated by Sanger sequencing and deep sequencing of target amplicons. The effect of GLI3 mutations on its transcriptional properties was evaluated by luciferase assays using reporters containing eight copies of the GLI‐binding site and a mutated control sequence disrupting GLI binding. Results We found hamartoma‐specific somatic truncation mutations in GLI3 and OFD1, known regulators of sonic hedgehog (Shh) signaling, in two and three individuals, respectively. Deep sequencing of amplicons covering the mutations showed mutant allele rates of 7–54%. Somatic mutations in OFD1 at Xp22 were found only in male individuals. Potential pathogenic somatic mutations in UBR5 and ZNF263 were also identified in each individual. Germline nonsense mutations in GLI3 and OFD1 were identified in each individual with PHS and OFD type I in our series, respectively. The truncated GLI3 showed stronger repressor activity than the wild‐type protein. We did not detect somatic mutations in the remaining 9 individuals. Interpretation Our data indicate that a spectrum of human disorders can be caused by lesion‐specific somatic mutations, and suggest that impaired Shh signaling is one of the pathomechanisms of HH.
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Affiliation(s)
- Hirotomo Saitsu
- Department of Human Genetics Yokohama City University Graduate School of Medicine Yokohama 236-0004 Japan; Department of Biochemistry Hamamatsu University School of Medicine Hamamatsu 431-3192 Japan
| | - Masaki Sonoda
- Department of Functional Neurosurgery Epilepsy Center Nishi-Niigata Chuo National Hospital Niigata 950-2085 Japan
| | - Takefumi Higashijima
- Department of Functional Neurosurgery Epilepsy Center Nishi-Niigata Chuo National Hospital Niigata 950-2085 Japan
| | - Hiroshi Shirozu
- Department of Functional Neurosurgery Epilepsy Center Nishi-Niigata Chuo National Hospital Niigata 950-2085 Japan
| | - Hiroshi Masuda
- Department of Functional Neurosurgery Epilepsy Center Nishi-Niigata Chuo National Hospital Niigata 950-2085 Japan
| | - Jun Tohyama
- Department of Child Neurology Nishi-Niigata Chuo National Hospital Niigata 950-2085 Japan
| | - Mitsuhiro Kato
- Department of Pediatrics Showa University School of Medicine Tokyo 142-8666 Japan
| | - Mitsuko Nakashima
- Department of Human Genetics Yokohama City University Graduate School of Medicine Yokohama 236-0004 Japan
| | - Yoshinori Tsurusaki
- Clinical Research Institute Kanagawa Children's Medical Center Yokohama 232-8555 Japan
| | - Takeshi Mizuguchi
- Department of Human Genetics Yokohama City University Graduate School of Medicine Yokohama 236-0004 Japan
| | - Satoko Miyatake
- Department of Human Genetics Yokohama City University Graduate School of Medicine Yokohama 236-0004 Japan
| | - Noriko Miyake
- Department of Human Genetics Yokohama City University Graduate School of Medicine Yokohama 236-0004 Japan
| | - Shigeki Kameyama
- Department of Functional Neurosurgery Epilepsy Center Nishi-Niigata Chuo National Hospital Niigata 950-2085 Japan
| | - Naomichi Matsumoto
- Department of Human Genetics Yokohama City University Graduate School of Medicine Yokohama 236-0004 Japan
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Behr C, Goltzene MA, Kosmalski G, Hirsch E, Ryvlin P. Epidemiology of epilepsy. Rev Neurol (Paris) 2016; 172:27-36. [PMID: 26754036 DOI: 10.1016/j.neurol.2015.11.003] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 11/24/2015] [Accepted: 11/24/2015] [Indexed: 12/25/2022]
Abstract
Epilepsy is a burden affecting no fewer than 50 million patients worldwide. It is a heterogeneous group of disorders comprising both common and very rare forms, thus rendering its epidemiological investigations rather difficult. Moreover, making an epilepsy diagnosis per se can be challenging due to an evolving system of classification, and its dependency on local habits and culture. Any attempt at meta-analyses must consider such biases when pooling data from different centers and countries. Differentiating a contextual seizure from chronic epilepsy is every epileptologist's daily mission, yet it is also crucial for achieving a proper estimation of the epidemiology of epilepsy. Our present objective was to provide an overview of the epidemiology of both syndromic and non-syndromic epilepsy. Most epileptic syndromes tend to be rare and, thus, the feasibility of epidemiological quantification in populations is also addressed. Regarding its prevalence and cost, epilepsy deserves greater attention than it generally receives, as it appears to continue to be a condition under persistent taboos.
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Affiliation(s)
- C Behr
- Department of neurology, university hospital of Strasbourg, 1, place de l'Hôpital, 67000 Strasbourg, France.
| | - M A Goltzene
- Department of neurology, university hospital of Strasbourg, 1, place de l'Hôpital, 67000 Strasbourg, France
| | - G Kosmalski
- Department of pharmacology, university hospital of Strasbourg, 1, place de l'Hôpital, 67000 Strasbourg, France
| | - E Hirsch
- Department of neurology, university hospital of Strasbourg, 1, place de l'Hôpital, 67000 Strasbourg, France
| | - P Ryvlin
- Department of clinical neurosciences, CHUV, champ de l'Air, 21, rue du Bugnon, 1011 Lausanne, Switzerland
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17
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Li MH, Eberhard M, Mudd P, Javia L, Zimmerman R, Khalek N, Zackai EH. Total colonic aganglionosis and imperforate anus in a severely affected infant with Pallister-Hall syndrome. Am J Med Genet A 2015; 167A:617-20. [PMID: 25604768 DOI: 10.1002/ajmg.a.36915] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 11/23/2014] [Indexed: 12/28/2022]
Abstract
Pallister-Hall syndrome is a complex malformation syndrome characterized by a wide range of anomalies including hypothalamic hamartoma, polydactyly, bifid epiglottis, and genitourinary abnormalities. It is usually caused by truncating frameshift/nonsense and splicing mutations in the middle third of GLI3. The clinical course ranges from mild to lethal in the neonatal period. We present the first patient with Pallister-Hall syndrome reported with total colonic aganglionosis, a rare form of Hirschsprung disease with poor long-term outcome. The patient also had an imperforate anus, which is the third individual with Pallister-Hall syndrome reported with both Hirschsprung disease and an imperforate anus. Molecular testing via amniocentesis showed an apparently de novo novel nonsense mutation c.2641 C>T (p.Gln881*). His overall medical course was difficult and was complicated by respiratory failure and pan-hypopituitarism. Invasive care was ultimately withdrawn, and the patient expired at three months of age. This patient's phenotype was complex with unusual gastrointestinal features ultimately leading to a unfavorable prognosis and outcome, highlighting the range of clinical severity in patients with Pallister-Hall syndrome.
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Affiliation(s)
- Mindy H Li
- Division of Human Genetics, Department of Pediatrics, University of Pennsylvania Perelman School of Medicine and The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
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18
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Hall JG. Pallister-Hall syndrome has gone the way of modern medical genetics. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2014; 166C:414-8. [DOI: 10.1002/ajmg.c.31419] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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19
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Pati S, Sollman M, Fife TD, Ng YT. Diagnosis and management of epilepsy associated with hypothalamic hamartoma: an evidence-based systematic review. J Child Neurol 2013; 28:909-16. [PMID: 23670254 DOI: 10.1177/0883073813488673] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The main objective was to review the evidence for management of epilepsy associated with hypothalamic hamartomas. We performed a systemic review of the literature through July 2012 that studied patients with hypothalamic hamartomas and related epilepsy. Articles meeting selection criteria were rated according to the American Academy of Neurology classification of evidence scheme. Recommendations were linked to the strength of the evidence and as follows: (a) precocious puberty is associated more with the pedunculated type and epilepsy typified by gelastic seizures with the sessile form of hypothalamic hamartomas (class III); (b) significant behavioral and cognitive deficits are associated with patients with hypothalamic hamartomas (class III); (c) video electroencephalography (EEG) findings are extremely variable particularly across the different ages and do not affect surgical outcome (class III); d) various surgical techniques (transcallosal and endoscopic resection) resulted in 49% to 54% seizure freedom, 15% with a pterional approach as well as about 40% with radiosurgery (class III).
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Affiliation(s)
- Sandipan Pati
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02411, USA.
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20
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Mittal S, Mittal M, Montes JL, Farmer JP, Andermann F. Hypothalamic hamartomas. Part 1. Clinical, neuroimaging, and neurophysiological characteristics. Neurosurg Focus 2013; 34:E6. [DOI: 10.3171/2013.3.focus1355] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Hypothalamic hamartomas are uncommon but well-recognized developmental malformations that are classically associated with gelastic seizures and other refractory seizure types. The clinical course is often progressive and, in addition to the catastrophic epileptic syndrome, patients commonly exhibit debilitating cognitive, behavioral, and psychiatric disturbances. Over the past decade, investigators have gained considerable knowledge into the pathobiological and neurophysiological properties of these rare lesions. In this review, the authors examine the causes and molecular biology of hypothalamic hamartomas as well as the principal clinical features, neuroimaging findings, and electrophysiological characteristics. The diverse surgical modalities and strategies used to manage these difficult lesions are outlined in the second article of this 2-part review.
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Affiliation(s)
- Sandeep Mittal
- 1Department of Neurosurgery, Comprehensive Epilepsy Center, Wayne State University, Detroit Medical Center, Detroit, Michigan
| | - Monika Mittal
- 1Department of Neurosurgery, Comprehensive Epilepsy Center, Wayne State University, Detroit Medical Center, Detroit, Michigan
| | | | | | - Frederick Andermann
- 3Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
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21
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Vortmeyer AO, Falke EA, Gläsker S, Li J, Oldfield EH. Nervous system involvement in von Hippel-Lindau disease: pathology and mechanisms. Acta Neuropathol 2013; 125:333-50. [PMID: 23400300 DOI: 10.1007/s00401-013-1091-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2012] [Revised: 01/25/2013] [Accepted: 01/26/2013] [Indexed: 02/06/2023]
Abstract
Patients with von Hippel-Lindau disease carry a germline mutation of the Von Hippel-Lindau (VHL) tumor-suppressor gene. We discuss the molecular consequences of loss of VHL gene function and their impact on the nervous system. Dysfunction of the VHL protein causes accumulation and activation of hypoxia inducible factor (HIF) which can be demonstrated in earliest stages of tumorigenesis and is followed by expression of VEGF, erythropoietin, nitric oxide synthase and glucose transporter 1 in VHL-deficient tumor cells. HIF-independent functions of VHL, epigenetic inactivation of VHL, pVHL proteostasis, and links between loss of VHL function and developmental arrest are also described. A most intriguing feature in VHL disease is the occurrence of primary hemangioblastic tumors in the nervous system, the origin of which has not yet been entirely clarified, and current hypotheses are discussed. Endolymphatic sac tumors may extend into the brain, but originally arise from proliferation of endolymphatic duct/sac epithelium; the exact nature of the proliferating epithelial cell, however, also has remained unclear, as well as the question why tumors almost consistently develop in the intraosseous portion of the endolymphatic sac/duct only. The epitheloid clear cell morphology of both advanced hemangioblastoma and renal clear cell carcinoma can make the differential diagnosis challenging, recent developments in immunohistochemical differentiation are discussed. Finally, metastasis to brain may not only be caused by renal carcinoma, but may derive from VHL disease-associated pheochromocytoma/paraganglioma, or pancreatic neuroendocrine tumor.
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Affiliation(s)
- Alexander O Vortmeyer
- Department of Pathology, Yale University School of Medicine, 416A Lauder Hall 310 Cedar Street, New Haven, CT 06520, USA.
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22
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Castaño De La Mota C, Martín Del Valle F, Pérez Villena A, Calleja Gero M, Losada Del Pozo R, Ruiz-Falcó Rojas M. Hypothalamic hamartoma in paediatric patients: Clinical characteristics, outcomes and review of the literature. NEUROLOGÍA (ENGLISH EDITION) 2012. [DOI: 10.1016/j.nrleng.2011.12.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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23
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Castaño De La Mota C, Martín Del Valle F, Pérez Villena A, Calleja Gero ML, Losada Del Pozo R, Ruiz-Falcó Rojas ML. Hamartoma hipotalámico en la edad pediátrica: características clínicas, evolución y revisión de la literatura. Neurologia 2012; 27:268-76. [PMID: 22341983 DOI: 10.1016/j.nrl.2011.12.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2011] [Revised: 11/06/2011] [Accepted: 12/20/2011] [Indexed: 12/01/2022] Open
Affiliation(s)
- C Castaño De La Mota
- Unidad de Neuropediatría, Hospital Infantil Universitario Niño Jesús, Madrid, España.
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Striano S, Santulli L, Ianniciello M, Ferretti M, Romanelli P, Striano P. The gelastic seizures-hypothalamic hamartoma syndrome: facts, hypotheses, and perspectives. Epilepsy Behav 2012; 24:7-13. [PMID: 22503469 DOI: 10.1016/j.yebeh.2012.02.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Revised: 02/12/2012] [Accepted: 02/14/2012] [Indexed: 11/15/2022]
Abstract
Hypothalamic hamartoma (HH) can be associated with a wide spectrum of epileptic conditions, ranging from a mild form with seizures characterized by urge to laugh and no cognitive involvement up to a catastrophic encephalopathy with early onset gelastic seizures (GS), precocious puberty, and mental retardation. Moreover, a refractory, either focal or generalized, epilepsy develops during the clinical course in nearly all the cases. Neurophysiologic and neuroimaging studies have demonstrated that HH itself generates GS and starts a process of secondary epileptogenesis responsible for refractory focal or generalized epilepsy. The intrinsic epileptogenicity of HH may be explained by the neurophysiological properties of small GABAergic, spontaneously firing HH neurons. Surgical ablation of HH can reverse epilepsy and encephalopathy. Gamma-knife radiosurgery and image-guided robotic radiosurgery seem to be useful and safe approaches for treatment, in particular of small HH. Here, we review this topic, based on literature reports and our personal observations. In addition, we discuss pathogenetic hypotheses and suggest new approaches to this intriguing issue.
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Affiliation(s)
- Salvatore Striano
- Epilepsy Center, Department of Neurological Sciences, Federico II University, Napoli, Italy.
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25
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Abstract
In vertebrate hedgehog signaling, hedgehog ligands are processed to become bilipidated and then multimerize, which allows them to leave the signaling cell via Dispatched 1 and become transported via glypicans and megalin to the responding cells. Hedgehog then interacts with a complex of Patched 1 and Cdo/Boc, which activates endocytic Smoothened to the cilium. Patched 1 regulates the activity of Smoothened (1) via Vitamin D3, which inhibits Smoothened in the absence of hedgehog ligand or (2) via oxysterols, which activate Smoothened in the presence of hedgehog ligand. Hedgehog ligands also interact with Hip1, Patched 2, and Gas1, which regulate the range as well as the level of hedgehog signaling. In vertebrates, Smoothened is shortened at its C-terminal end and lacks most of the phosphorylation sites of importance in Drosophila. Cos2, also of importance in Drosophila, plays no role in mammalian transduction, nor do its homologs Kif7 and Kif27. The cilium may provide a function analogous to that of Cos2 by linking Smoothened to the modulation of Gli transcription factors. Disorders associated with the hedgehog signaling network follow, including nevoid basal cell carcinoma syndrome, holoprosencephaly, Smith-Lemli-Opitz syndrome, Greig cephalopolysyndactyly syndrome, Pallister-Hall syndrome, Carpenter syndrome, and Rubinstein-Taybi syndrome.
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Affiliation(s)
- M Michael Cohen
- Department of Pediatrics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada.
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26
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Castori M. Holoprosencephaly-diencephalic hamartoma: sequence or pleiotropy? Am J Med Genet A 2009; 152A:264-6; author reply 267-8. [PMID: 20034093 DOI: 10.1002/ajmg.a.33165] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Lekovic GP, Kerrigan JF, Wait S, Rekate HL, Steinmetz PN. IN SITU SINGLE-UNIT RECORDING OF HYPOTHALAMIC HAMARTOMAS UNDER ENDOSCOPIC DIRECT VISUALIZATION. Neurosurgery 2009; 65:E1195-6; discussion E1196. [DOI: 10.1227/01.neu.0000359531.45021.52] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Abstract
OBJECTIVE
Hypothalamic hamartomas (HHs) are associated with refractory epilepsy and are amenable to surgical treatment. The gelastic seizures associated with HHs originate within the HH lesion, but the responsible cellular mechanisms are unknown. Microelectrode patch-clamp recordings from HH neurons in resected slice preparations show that small HH neurons spontaneously fire with intrinsic pacemaker-like activity. We questioned whether spontaneous firing of HH neurons was present in situ, and we hypothesized that single-unit field recordings from HH tissue could be obtained with instrumentation passed through the endoscope before surgical resection.
TECHNIQUE
After informed consent was obtained, patients undergoing transventricular, endoscopic resection of an HH for intractable epilepsy were eligible for study. After placement of the endoscope, a bundled microwire (total of 9 contacts) was placed into the HH under direct visualization. Spontaneous activity was recorded for two or three 5-minute epochs, under steady-state general anesthesia. The wire was advanced 0.5 to 1 mm within the lesion between recording epochs.
RESULTS
A total of thirteen 5-minute recordings were obtained from 5 patients. Noise levels were comparable to extraoperative microwire recordings for temporal lobe epilepsy. Single-neuron spike activity was isolated from a total of 5 channels obtained during recording of 3 sessions in 3 patients.
CONCLUSION
We have shown that single-unit recordings from HH lesions can be successfully obtained in situ under direct endoscopic visualization. We believe that this is the first report using the working channel of a neuroendoscope to make physiological recordings of deep structures in humans.
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Affiliation(s)
- Gregory P. Lekovic
- Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
| | - John F. Kerrigan
- Division of Neurology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
| | - Scott Wait
- Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
| | - Harold L. Rekate
- Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
| | - Peter N. Steinmetz
- Divisions of Neurological Surgery and Neurology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
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28
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Striano S, Striano P, Coppola A, Romanelli P. The syndrome gelastic seizures-hypothalamic hamartoma: Severe, potentially reversible encephalopathy. Epilepsia 2009; 50 Suppl 5:62-5. [DOI: 10.1111/j.1528-1167.2009.02125.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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