Inborn errors of CACNA1A-encoded P/Q-type calcium channels impair synaptic transmission, producing early and lifelong neurological deficits, including childhood absence epilepsy, ataxia and dystonia. Whether these impairments owe their pathologies to defective channel function during the critical period for thalamic network stabilization in immature brain remains unclear. Here we show that mice with tamoxifen-induced adult-onset ablation of P/Q channel alpha subunit (iKOp/q) display identical patterns of dysfunction, replicating the inborn loss of function phenotypes and, therefore demonstrate that these neurological defects do not rely upon developmental abnormality. Unexpectedly, unlike the inborn model, the adult-onset pattern of excitability changes believed to be pathogenic within the thalamic network is non-canonical. Specifically, adult ablation of P/Q channels does not promote Cacna1g-mediated burst firing or T-type calcium current (IT) in the thalamocortical relay neurons; however, burst firing in thalamocortical relay neurons remains essential as iKOp/q mice generated on a Cacna1g deleted background show substantially diminished seizure generation. Moreover, in thalamic reticular nucleus neurons, burst firing is impaired accompanied by attenuated IT. Interestingly, inborn deletion of thalamic reticular nucleus-enriched, human childhood absence epilepsy-linked gene Cacna1h in iKOp/q mice reduces thalamic reticular nucleus burst firing and promotes rather than reduces seizure, indicating an epileptogenic role for loss of function Cacna1h gene variants reported in human childhood absence epilepsy cases. Together, our results demonstrate that P/Q channels remain critical for maintaining normal thalamocortical oscillations and motor control in the adult brain, and suggest that the developmental plasticity of membrane currents regulating pathological rhythmicity is both degenerate and age-dependent.
{"title":"Adult loss of Cacna1a in mice recapitulates childhood absence epilepsy by distinct thalamic bursting mechanisms.","authors":"Qing-long Miao, S. Herlitze, M. Mark, J. Noebels","doi":"10.1093/brain/awz365","DOIUrl":"https://doi.org/10.1093/brain/awz365","url":null,"abstract":"Inborn errors of CACNA1A-encoded P/Q-type calcium channels impair synaptic transmission, producing early and lifelong neurological deficits, including childhood absence epilepsy, ataxia and dystonia. Whether these impairments owe their pathologies to defective channel function during the critical period for thalamic network stabilization in immature brain remains unclear. Here we show that mice with tamoxifen-induced adult-onset ablation of P/Q channel alpha subunit (iKOp/q) display identical patterns of dysfunction, replicating the inborn loss of function phenotypes and, therefore demonstrate that these neurological defects do not rely upon developmental abnormality. Unexpectedly, unlike the inborn model, the adult-onset pattern of excitability changes believed to be pathogenic within the thalamic network is non-canonical. Specifically, adult ablation of P/Q channels does not promote Cacna1g-mediated burst firing or T-type calcium current (IT) in the thalamocortical relay neurons; however, burst firing in thalamocortical relay neurons remains essential as iKOp/q mice generated on a Cacna1g deleted background show substantially diminished seizure generation. Moreover, in thalamic reticular nucleus neurons, burst firing is impaired accompanied by attenuated IT. Interestingly, inborn deletion of thalamic reticular nucleus-enriched, human childhood absence epilepsy-linked gene Cacna1h in iKOp/q mice reduces thalamic reticular nucleus burst firing and promotes rather than reduces seizure, indicating an epileptogenic role for loss of function Cacna1h gene variants reported in human childhood absence epilepsy cases. Together, our results demonstrate that P/Q channels remain critical for maintaining normal thalamocortical oscillations and motor control in the adult brain, and suggest that the developmental plasticity of membrane currents regulating pathological rhythmicity is both degenerate and age-dependent.","PeriodicalId":121505,"journal":{"name":"Brain : a journal of neurology","volume":"160 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122921647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hugo Morales‐Briceño, S. Mohammad, B. Post, A. Fois, R. Dale, M. Tchan, V. Fung
Genetic early-onset parkinsonism presenting from infancy to adolescence (≤21 years old) is a clinically diverse syndrome often combined with other hyperkinetic movement disorders, neurological and imaging abnormalities. The syndrome is genetically heterogeneous, with many causative genes already known. With the increased use of next-generation sequencing in clinical practice, there have been novel and unexpected insights into phenotype-genotype correlations and the discovery of new disease-causing genes. It is now recognized that mutations in a single gene can give rise to a broad phenotypic spectrum and that, conversely different genetic disorders can manifest with a similar phenotype. Accurate phenotypic characterization remains an essential step in interpreting genetic findings in undiagnosed patients. However, in the past decade, there has been a marked expansion in knowledge about the number of both disease-causing genes and phenotypic spectrum of early-onset cases. Detailed knowledge of genetic disorders and their clinical expression is required for rational planning of genetic and molecular testing, as well as correct interpretation of next-generation sequencing results. In this review we examine the relevant literature of genetic parkinsonism with ≤21 years onset, extracting data on associated movement disorders as well as other neurological and imaging features, to delineate syndromic patterns associated with early-onset parkinsonism. Excluding PRKN (parkin) mutations, >90% of the presenting phenotypes have a complex or atypical presentation, with dystonia, abnormal cognition, pyramidal signs, neuropsychiatric disorders, abnormal imaging and abnormal eye movements being the most common features. Furthermore, several imaging features and extraneurological manifestations are relatively specific for certain disorders and are important diagnostic clues. From the currently available literature, the most commonly implicated causes of early-onset parkinsonism have been elucidated but diagnosis is still challenging in many cases. Mutations in ∼70 different genes have been associated with early-onset parkinsonism or may feature parkinsonism as part of their phenotypic spectrum. Most of the cases are caused by recessively inherited mutations, followed by dominant and X-linked mutations, and rarely by mitochondrially inherited mutations. In infantile-onset parkinsonism, the phenotype of hypokinetic-rigid syndrome is most commonly caused by disorders of monoamine synthesis. In childhood and juvenile-onset cases, common genotypes include PRKN, HTT, ATP13A2, ATP1A3, FBX07, PINK1 and PLA2G6 mutations. Moreover, Wilson's disease and mutations in the manganese transporter are potentially treatable conditions and should always be considered in the differential diagnosis in any patient with early-onset parkinsonism.
{"title":"Clinical and neuroimaging phenotypes of genetic parkinsonism from infancy to adolescence.","authors":"Hugo Morales‐Briceño, S. Mohammad, B. Post, A. Fois, R. Dale, M. Tchan, V. Fung","doi":"10.1093/brain/awz345","DOIUrl":"https://doi.org/10.1093/brain/awz345","url":null,"abstract":"Genetic early-onset parkinsonism presenting from infancy to adolescence (≤21 years old) is a clinically diverse syndrome often combined with other hyperkinetic movement disorders, neurological and imaging abnormalities. The syndrome is genetically heterogeneous, with many causative genes already known. With the increased use of next-generation sequencing in clinical practice, there have been novel and unexpected insights into phenotype-genotype correlations and the discovery of new disease-causing genes. It is now recognized that mutations in a single gene can give rise to a broad phenotypic spectrum and that, conversely different genetic disorders can manifest with a similar phenotype. Accurate phenotypic characterization remains an essential step in interpreting genetic findings in undiagnosed patients. However, in the past decade, there has been a marked expansion in knowledge about the number of both disease-causing genes and phenotypic spectrum of early-onset cases. Detailed knowledge of genetic disorders and their clinical expression is required for rational planning of genetic and molecular testing, as well as correct interpretation of next-generation sequencing results. In this review we examine the relevant literature of genetic parkinsonism with ≤21 years onset, extracting data on associated movement disorders as well as other neurological and imaging features, to delineate syndromic patterns associated with early-onset parkinsonism. Excluding PRKN (parkin) mutations, >90% of the presenting phenotypes have a complex or atypical presentation, with dystonia, abnormal cognition, pyramidal signs, neuropsychiatric disorders, abnormal imaging and abnormal eye movements being the most common features. Furthermore, several imaging features and extraneurological manifestations are relatively specific for certain disorders and are important diagnostic clues. From the currently available literature, the most commonly implicated causes of early-onset parkinsonism have been elucidated but diagnosis is still challenging in many cases. Mutations in ∼70 different genes have been associated with early-onset parkinsonism or may feature parkinsonism as part of their phenotypic spectrum. Most of the cases are caused by recessively inherited mutations, followed by dominant and X-linked mutations, and rarely by mitochondrially inherited mutations. In infantile-onset parkinsonism, the phenotype of hypokinetic-rigid syndrome is most commonly caused by disorders of monoamine synthesis. In childhood and juvenile-onset cases, common genotypes include PRKN, HTT, ATP13A2, ATP1A3, FBX07, PINK1 and PLA2G6 mutations. Moreover, Wilson's disease and mutations in the manganese transporter are potentially treatable conditions and should always be considered in the differential diagnosis in any patient with early-onset parkinsonism.","PeriodicalId":121505,"journal":{"name":"Brain : a journal of neurology","volume":"307 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131843672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Koronyo-Hamaoui, J. Sheyn, Eric Y. Hayden, Songlin Li, D. Fuchs, Giovanna C Regis, D. Lopes, K. Black, K. Bernstein, D. Teplow, S. Fuchs, Y. Koronyo, A. Rentsendorj
Targeted overexpression of angiotensin-converting enzyme (ACE), an amyloid-β protein degrading enzyme, to brain resident microglia and peripheral myelomonocytes (ACE10 model) substantially diminished Alzheimer's-like disease in double-transgenic APPSWE/PS1ΔE9 (AD+) mice. In this study, we explored the impact of selective and transient angiotensin-converting enzyme overexpression on macrophage behaviour and the relative contribution of bone marrow-derived ACE10 macrophages, but not microglia, in attenuating disease progression. To this end, two in vivo approaches were applied in AD+ mice: (i) ACE10/GFP+ bone marrow transplantation with head shielding; and (ii) adoptive transfer of CD115+-ACE10/GFP+ monocytes to the peripheral blood. Extensive in vitro studies were further undertaken to establish the unique ACE10-macrophage phenotype(s) in response to amyloid-β1-42 fibrils and oligomers. The combined in vivo approaches showed that increased cerebral infiltration of ACE10 as compared to wild-type monocytes (∼3-fold increase; P < 0.05) led to reductions in cerebral soluble amyloid-β1-42, vascular and parenchymal amyloid-β deposits, and astrocytosis (31%, 47-80%, and 33%, respectively; P < 0.05-0.0001). ACE10 macrophages surrounded brain and retinal amyloid-β plaques and expressed 3.2-fold higher insulin-like growth factor-1 (P < 0.01) and ∼60% lower tumour necrosis factor-α (P < 0.05). Importantly, blood enrichment with CD115+-ACE10 monocytes in symptomatic AD+ mice resulted in pronounced synaptic and cognitive preservation (P < 0.05-0.001). In vitro analysis of macrophage response to well-defined amyloid-β1-42 conformers (fibrils, prion rod-like structures, and stabilized soluble oligomers) revealed extensive resistance to amyloid-β1-42 species by ACE10 macrophages. They exhibited 2-5-fold increased surface binding to amyloid-β conformers as well as substantially more effective amyloid-β1-42 uptake, at least 8-fold higher than those of wild-type macrophages (P < 0.0001), which were associated with enhanced expression of surface scavenger receptors (i.e. CD36, scavenger receptor class A member 1, triggering receptor expressed on myeloid cells 2, CD163; P < 0.05-0.0001), endosomal processing (P < 0.05-0.0001), and ∼80% increased extracellular degradation of amyloid-β1-42 (P < 0.001). Beneficial ACE10 phenotype was reversed by the angiotensin-converting enzyme inhibitor (lisinopril) and thus was dependent on angiotensin-converting enzyme catalytic activity. Further, ACE10 macrophages presented distinct anti-inflammatory (low inducible nitric oxide synthase and lower tumour necrosis factor-α), pro-healing immune profiles (high insulin-like growth factor-1, elongated cell morphology), even following exposure to Alzheimer's-related amyloid-β1-42 oligomers. Overall, we provide the first evidence for therapeutic roles of angiotensin-converting enzyme-overexpressing macrophages in preserving synapses and cognition, attenuating neuropathology and neuroinflamm
{"title":"Peripherally derived angiotensin converting enzyme-enhanced macrophages alleviate Alzheimer-related disease.","authors":"M. Koronyo-Hamaoui, J. Sheyn, Eric Y. Hayden, Songlin Li, D. Fuchs, Giovanna C Regis, D. Lopes, K. Black, K. Bernstein, D. Teplow, S. Fuchs, Y. Koronyo, A. Rentsendorj","doi":"10.1093/brain/awz364","DOIUrl":"https://doi.org/10.1093/brain/awz364","url":null,"abstract":"Targeted overexpression of angiotensin-converting enzyme (ACE), an amyloid-β protein degrading enzyme, to brain resident microglia and peripheral myelomonocytes (ACE10 model) substantially diminished Alzheimer's-like disease in double-transgenic APPSWE/PS1ΔE9 (AD+) mice. In this study, we explored the impact of selective and transient angiotensin-converting enzyme overexpression on macrophage behaviour and the relative contribution of bone marrow-derived ACE10 macrophages, but not microglia, in attenuating disease progression. To this end, two in vivo approaches were applied in AD+ mice: (i) ACE10/GFP+ bone marrow transplantation with head shielding; and (ii) adoptive transfer of CD115+-ACE10/GFP+ monocytes to the peripheral blood. Extensive in vitro studies were further undertaken to establish the unique ACE10-macrophage phenotype(s) in response to amyloid-β1-42 fibrils and oligomers. The combined in vivo approaches showed that increased cerebral infiltration of ACE10 as compared to wild-type monocytes (∼3-fold increase; P < 0.05) led to reductions in cerebral soluble amyloid-β1-42, vascular and parenchymal amyloid-β deposits, and astrocytosis (31%, 47-80%, and 33%, respectively; P < 0.05-0.0001). ACE10 macrophages surrounded brain and retinal amyloid-β plaques and expressed 3.2-fold higher insulin-like growth factor-1 (P < 0.01) and ∼60% lower tumour necrosis factor-α (P < 0.05). Importantly, blood enrichment with CD115+-ACE10 monocytes in symptomatic AD+ mice resulted in pronounced synaptic and cognitive preservation (P < 0.05-0.001). In vitro analysis of macrophage response to well-defined amyloid-β1-42 conformers (fibrils, prion rod-like structures, and stabilized soluble oligomers) revealed extensive resistance to amyloid-β1-42 species by ACE10 macrophages. They exhibited 2-5-fold increased surface binding to amyloid-β conformers as well as substantially more effective amyloid-β1-42 uptake, at least 8-fold higher than those of wild-type macrophages (P < 0.0001), which were associated with enhanced expression of surface scavenger receptors (i.e. CD36, scavenger receptor class A member 1, triggering receptor expressed on myeloid cells 2, CD163; P < 0.05-0.0001), endosomal processing (P < 0.05-0.0001), and ∼80% increased extracellular degradation of amyloid-β1-42 (P < 0.001). Beneficial ACE10 phenotype was reversed by the angiotensin-converting enzyme inhibitor (lisinopril) and thus was dependent on angiotensin-converting enzyme catalytic activity. Further, ACE10 macrophages presented distinct anti-inflammatory (low inducible nitric oxide synthase and lower tumour necrosis factor-α), pro-healing immune profiles (high insulin-like growth factor-1, elongated cell morphology), even following exposure to Alzheimer's-related amyloid-β1-42 oligomers. Overall, we provide the first evidence for therapeutic roles of angiotensin-converting enzyme-overexpressing macrophages in preserving synapses and cognition, attenuating neuropathology and neuroinflamm","PeriodicalId":121505,"journal":{"name":"Brain : a journal of neurology","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132934598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Hypercalcaemia rather than high dose vitamin D3 supplements could exacerbate multiple sclerosis.","authors":"J. Smolders, J. Damoiseaux, R. Hupperts","doi":"10.1093/brain/awz339","DOIUrl":"https://doi.org/10.1093/brain/awz339","url":null,"abstract":"","PeriodicalId":121505,"journal":{"name":"Brain : a journal of neurology","volume":"241 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130965765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This scientific commentary refers to ‘Virtual resection predicts surgical outcome for drug-resistant epilepsy’ by Kini et al. (doi:10.1093/brain/awz303).
{"title":"Graph theory for EEG: can we learn to trust another black box?","authors":"Garnett C Smith, W. Stacey","doi":"10.1093/brain/awz369","DOIUrl":"https://doi.org/10.1093/brain/awz369","url":null,"abstract":"This scientific commentary refers to ‘Virtual resection predicts surgical outcome for drug-resistant epilepsy’ by Kini et al. (doi:10.1093/brain/awz303).","PeriodicalId":121505,"journal":{"name":"Brain : a journal of neurology","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130439956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Targeting network dysfunction in neurodegenerative diseases.","authors":"M. Husain","doi":"10.1093/brain/awz347","DOIUrl":"https://doi.org/10.1093/brain/awz347","url":null,"abstract":"","PeriodicalId":121505,"journal":{"name":"Brain : a journal of neurology","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129041789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alessandro Esposito, A. Falace, M. Wagner, M. Gal, D. Mei, V. Conti, T. Pisano, D. Aprile, Maria Sabina Cerullo, A. De Fusco, S. Giovedì, A. Seibt, D. Magen, T. Polster, A. Eran, S. L. Stenton, C. Fiorillo, S. Ravid, E. Mayatepek, H. Hafner, S. Wortmann, E. Levanon, C. Marini, H. Mandel, F. Benfenati, F. Distelmaier, A. Fassio, R. Guerrini
Ohtahara syndrome, early infantile epileptic encephalopathy with a suppression burst EEG pattern, is an aetiologically heterogeneous condition starting in the first weeks or months of life with intractable seizures and profound developmental disability. Using whole exome sequencing, we identified biallelic DMXL2 mutations in three sibling pairs with Ohtahara syndrome, belonging to three unrelated families. Siblings in Family 1 were compound heterozygous for the c.5135C>T (p.Ala1712Val) missense substitution and the c.4478C>G (p.Ser1493*) nonsense substitution; in Family 2 were homozygous for the c.4478C>A (p.Ser1493*) nonsense substitution and in Family 3 were homozygous for the c.7518-1G>A (p.Trp2507Argfs*4) substitution. The severe developmental and epileptic encephalopathy manifested from the first day of life and was associated with deafness, mild peripheral polyneuropathy and dysmorphic features. Early brain MRI investigations in the first months of life revealed thin corpus callosum with brain hypomyelination in all. Follow-up MRI scans in three patients revealed progressive moderate brain shrinkage with leukoencephalopathy. Five patients died within the first 9 years of life and none achieved developmental, communicative or motor skills following birth. These clinical findings are consistent with a developmental brain disorder that begins in the prenatal brain, prevents neural connections from reaching the expected stages at birth, and follows a progressive course. DMXL2 is highly expressed in the brain and at synaptic terminals, regulates v-ATPase assembly and activity and participates in intracellular signalling pathways; however, its functional role is far from complete elucidation. Expression analysis in patient-derived skin fibroblasts demonstrated absence of the DMXL2 protein, revealing a loss of function phenotype. Patients' fibroblasts also exhibited an increased LysoTracker® signal associated with decreased endolysosomal markers and degradative processes. Defective endolysosomal homeostasis was accompanied by impaired autophagy, revealed by lower LC3II signal, accumulation of polyubiquitinated proteins, and autophagy receptor p62, with morphological alterations of the autolysosomal structures on electron microscopy. Altered lysosomal homeostasis and defective autophagy were recapitulated in Dmxl2-silenced mouse hippocampal neurons, which exhibited impaired neurite elongation and synaptic loss. Impaired lysosomal function and autophagy caused by biallelic DMXL2 mutations affect neuronal development and synapse formation and result in Ohtahara syndrome with profound developmental impairment and reduced life expectancy.
{"title":"Biallelic DMXL2 mutations impair autophagy and cause Ohtahara syndrome with progressive course.","authors":"Alessandro Esposito, A. Falace, M. Wagner, M. Gal, D. Mei, V. Conti, T. Pisano, D. Aprile, Maria Sabina Cerullo, A. De Fusco, S. Giovedì, A. Seibt, D. Magen, T. Polster, A. Eran, S. L. Stenton, C. Fiorillo, S. Ravid, E. Mayatepek, H. Hafner, S. Wortmann, E. Levanon, C. Marini, H. Mandel, F. Benfenati, F. Distelmaier, A. Fassio, R. Guerrini","doi":"10.1093/brain/awz326","DOIUrl":"https://doi.org/10.1093/brain/awz326","url":null,"abstract":"Ohtahara syndrome, early infantile epileptic encephalopathy with a suppression burst EEG pattern, is an aetiologically heterogeneous condition starting in the first weeks or months of life with intractable seizures and profound developmental disability. Using whole exome sequencing, we identified biallelic DMXL2 mutations in three sibling pairs with Ohtahara syndrome, belonging to three unrelated families. Siblings in Family 1 were compound heterozygous for the c.5135C>T (p.Ala1712Val) missense substitution and the c.4478C>G (p.Ser1493*) nonsense substitution; in Family 2 were homozygous for the c.4478C>A (p.Ser1493*) nonsense substitution and in Family 3 were homozygous for the c.7518-1G>A (p.Trp2507Argfs*4) substitution. The severe developmental and epileptic encephalopathy manifested from the first day of life and was associated with deafness, mild peripheral polyneuropathy and dysmorphic features. Early brain MRI investigations in the first months of life revealed thin corpus callosum with brain hypomyelination in all. Follow-up MRI scans in three patients revealed progressive moderate brain shrinkage with leukoencephalopathy. Five patients died within the first 9 years of life and none achieved developmental, communicative or motor skills following birth. These clinical findings are consistent with a developmental brain disorder that begins in the prenatal brain, prevents neural connections from reaching the expected stages at birth, and follows a progressive course. DMXL2 is highly expressed in the brain and at synaptic terminals, regulates v-ATPase assembly and activity and participates in intracellular signalling pathways; however, its functional role is far from complete elucidation. Expression analysis in patient-derived skin fibroblasts demonstrated absence of the DMXL2 protein, revealing a loss of function phenotype. Patients' fibroblasts also exhibited an increased LysoTracker® signal associated with decreased endolysosomal markers and degradative processes. Defective endolysosomal homeostasis was accompanied by impaired autophagy, revealed by lower LC3II signal, accumulation of polyubiquitinated proteins, and autophagy receptor p62, with morphological alterations of the autolysosomal structures on electron microscopy. Altered lysosomal homeostasis and defective autophagy were recapitulated in Dmxl2-silenced mouse hippocampal neurons, which exhibited impaired neurite elongation and synaptic loss. Impaired lysosomal function and autophagy caused by biallelic DMXL2 mutations affect neuronal development and synapse formation and result in Ohtahara syndrome with profound developmental impairment and reduced life expectancy.","PeriodicalId":121505,"journal":{"name":"Brain : a journal of neurology","volume":"172 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126750432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Reply: Dynamic functional connectivity changes in Lewy body disease.","authors":"R. Biundo, E. Fiorenzato, A. Antonini","doi":"10.1093/brain/awz316","DOIUrl":"https://doi.org/10.1093/brain/awz316","url":null,"abstract":"","PeriodicalId":121505,"journal":{"name":"Brain : a journal of neurology","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131850032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mary B Makarious, M. Diez-Fairen, L. Krohn, C. Blauwendraat, S. Bandres-Ciga, Jinhui Ding, L. Pihlstrøm, H. Houlden, Sonja W. Scholz, Z. Gan-Or
{"title":"ARSA variants in α-synucleinopathies.","authors":"Mary B Makarious, M. Diez-Fairen, L. Krohn, C. Blauwendraat, S. Bandres-Ciga, Jinhui Ding, L. Pihlstrøm, H. Houlden, Sonja W. Scholz, Z. Gan-Or","doi":"10.1093/brain/awz340","DOIUrl":"https://doi.org/10.1093/brain/awz340","url":null,"abstract":"","PeriodicalId":121505,"journal":{"name":"Brain : a journal of neurology","volume":"124 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123202205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This scientific commentary refers to ‘Evolutionary modifications in human brain connectivity associated with schizophrenia’ by van den Heuvel et al. (doi:10.1093/brain/awz330).
这篇科学评论引用了van den Heuvel等人的“与精神分裂症相关的人类大脑连接的进化修改”(doi:10.1093/brain/awz330)。
{"title":"Towards a natural history of schizophrenia.","authors":"P. Vértes, J. Seidlitz","doi":"10.1093/brain/awz353","DOIUrl":"https://doi.org/10.1093/brain/awz353","url":null,"abstract":"This scientific commentary refers to ‘Evolutionary modifications in human brain connectivity associated with schizophrenia’ by van den Heuvel et al. (doi:10.1093/brain/awz330).","PeriodicalId":121505,"journal":{"name":"Brain : a journal of neurology","volume":"230 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115993368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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