1
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Specchio N, Trivisano M, Lenge M, Ferretti A, Mei D, Parrini E, Napolitano A, Rossi-Espagnet C, Talenti G, Longo D, Proietti J, Ragona F, Freri E, Solazzi R, Granata T, Darra F, Bernardina BD, Vigevano F, Guerrini R. CDKL5 deficiency disorder: progressive brain atrophy may be part of the syndrome. Cereb Cortex 2023; 33:9709-9717. [PMID: 37429835 PMCID: PMC10472491 DOI: 10.1093/cercor/bhad235] [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: 02/10/2023] [Revised: 04/17/2023] [Accepted: 06/19/2023] [Indexed: 07/12/2023] Open
Abstract
The clinical phenotype of Cyclin-Dependent Kinase-Like 5 (CDKL5) deficiency disorder (CDD) has been delineated but neuroimaging features have not been systematically analyzed. We studied brain magnetic resonance imaging (MRI) scans in a cohort of CDD patients and reviewed age at seizure onset, seizure semiology, head circumference. Thirty-five brain MRI from 22 unrelated patients were included. The median age at study entry was 13.4 years. In 14/22 patients (85.7%), MRI in the first year of life was unremarkable in all but two. In 11/22, we performed MRI after 24 months of age (range 2.5-23 years). In 8 out of 11 (72.7%), MRI showed supratentorial atrophy and in six cerebellar atrophy. Quantitative analysis detected volumetric reduction of the whole brain (-17.7%, P-value = 0.014), including both white matter (-25.7%, P-value = 0.005) and cortical gray matter (-9.1%, P-value = 0.098), with a reduction of surface area (-18.0%, P-value = 0.032), mainly involving the temporal regions, correlated with the head circumference (ρ = 0.79, P-value = 0.109). Both the qualitative structural assessment and the quantitative analysis detected brain volume reduction involving the gray and white matter. These neuroimaging findings may be related to either progressive changes due to CDD pathogenesis, or to the extreme severity of epilepsy, or both. Larger prospective studies are needed to clarify the bases for the structural changes we observed.
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Affiliation(s)
- Nicola Specchio
- Clinical and Experimental Neurology, Bambino Gesù Children’s Hospital IRCCS, Rome 00165, Italy
| | - Marina Trivisano
- Clinical and Experimental Neurology, Bambino Gesù Children’s Hospital IRCCS, Rome 00165, Italy
| | - Matteo Lenge
- Neuroscience Department, Meyer Children's Hospital IRCCS, Florence, 50139, Italy
| | - Alessandro Ferretti
- Clinical and Experimental Neurology, Bambino Gesù Children’s Hospital IRCCS, Rome 00165, Italy
| | - Davide Mei
- Neuroscience Department, Meyer Children's Hospital IRCCS, Florence, 50139, Italy
| | - Elena Parrini
- Neuroscience Department, Meyer Children's Hospital IRCCS, Florence, 50139, Italy
| | - Antonio Napolitano
- Medical Physics Unit, Enterprise Risk Management, Bambino Gesù Children's Hospital, IRCCS, Rome 00165, Italy
| | - Camilla Rossi-Espagnet
- Functional and Interventional Neuroimaging Unit, Bambino Gesù Children's Hospital, IRCCS, Rome 00165, Italy
| | - Giacomo Talenti
- Neuroradiology Unit, Neuroradiology Unit, Azienda Ospedale-Università di Padova, Padova 35128, Italy
| | - Daniela Longo
- Functional and Interventional Neuroimaging Unit, Bambino Gesù Children's Hospital, IRCCS, Rome 00165, Italy
| | - Jacopo Proietti
- Child Neuropsychiatry Unit, Department of Surgical Sciences, Dentistry, Gynecology and Pediatrics, University of Verona, Verona 37121, Italy
| | - Francesca Ragona
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano 20133, Italy
| | - Elena Freri
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano 20133, Italy
| | - Roberta Solazzi
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano 20133, Italy
| | - Tiziana Granata
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano 20133, Italy
| | - Francesca Darra
- Child Neuropsychiatry Unit, Department of Surgical Sciences, Dentistry, Gynecology and Pediatrics, University of Verona, Verona 37121, Italy
| | - Bernardo Dalla Bernardina
- Child Neuropsychiatry Unit, Department of Surgical Sciences, Dentistry, Gynecology and Pediatrics, University of Verona, Verona 37121, Italy
| | - Federico Vigevano
- Research Area on Neurology and Neurorehabilitation, Bambino Gesù Children’s Hospital IRCCS, Rome 00050, Italy
| | - Renzo Guerrini
- Neuroscience Department, Meyer Children's Hospital IRCCS, Florence, 50139, Italy
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2
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CDKL5 deficiency causes epileptic seizures independent of cellular mosaicism. J Neurol Sci 2022; 443:120498. [PMID: 36417806 DOI: 10.1016/j.jns.2022.120498] [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: 07/20/2022] [Revised: 10/06/2022] [Accepted: 11/12/2022] [Indexed: 11/17/2022]
Abstract
OBJECTIVE In a study using a mouse model of CDKL5 deficiency disorder (CDD), seizures are specific to female mice heterozygous for Cdkl5 mutations and not observed in hemizygous knockout males or homozygous knockout females. The aim of this study was to examine whether the clinical phenotype of patients with CDD can be impacted by the type of genetic variant. METHODS Eleven CDD patients (six females and five males) were included in this study. The molecular diagnosis of hemizygous male patients was performed using digital PCR and their clinical phenotypes were compared with those of patients with mosaic or heterozygous CDKL5 variants. The severity of clinical phenotypes was graded by using CDKL5 Developmental Score and the adapted version of the CDKL5 Clinical Severity Assessment. The effect of cellular mosaicism on the severity of CDD was studied by comparing the clinical characteristics and comorbidities between individuals with hemizygous and mosaic or heterozygous CDKL5 variants. RESULTS One of the five male patients was mosaic for the CDKL5 variant. All patients developed seizures irrespective of their genetic status of the pathogenic variant. However, cellular mosaicism of CDKL5 deficiency was associated with lesser severity of other comorbidities such as feeding, respiratory, and visual functional impairments. SIGNIFICANCE This study provided evidence that cellular mosaicism of CDKL5 deficiency was not necessarily required for developing epilepsy. CDD patients not only exhibited clinical features of epilepsy but also exhibited the developmental consequences arising directly from the effect of the CDKL5 pathogenic variant.
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3
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Gennaccaro L, Fuchs C, Loi M, Pizzo R, Alvente S, Berteotti C, Lupori L, Sagona G, Galvani G, Gurgone A, Raspanti A, Medici G, Tassinari M, Trazzi S, Ren E, Rimondini R, Pizzorusso T, Giovanna Z, Maurizio G, Elisabetta C. Age-Related Cognitive and Motor Decline in a Mouse Model of CDKL5 Deficiency Disorder is Associated with Increased Neuronal Senescence and Death. Aging Dis 2021; 12:764-785. [PMID: 34094641 PMCID: PMC8139207 DOI: 10.14336/ad.2020.0827] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 08/27/2020] [Indexed: 01/02/2023] Open
Abstract
CDKL5 deficiency disorder (CDD) is a severe neurodevelopmental disease caused by mutations in the X-linked CDKL5 gene. Children affected by CDD display a clinical phenotype characterized by early-onset epilepsy, intellectual disability, motor impairment, and autistic-like features. Although the clinical aspects associated with CDKL5 mutations are well described in children, adults with CDD are still under-characterized. Similarly, most animal research has been carried out on young adult Cdkl5 knockout (KO) mice only. Since age represents a risk factor for the worsening of symptoms in many neurodevelopmental disorders, understanding age differences in the development of behavioral deficits is crucial in order to optimize the impact of therapeutic interventions. Here, we compared young adult Cdkl5 KO mice with middle-aged Cdkl5 KO mice, at a behavioral, neuroanatomical, and molecular level. We found an age-dependent decline in motor, cognitive, and social behaviors in Cdkl5 KO mice, as well as in breathing and sleep patterns. The behavioral decline in older Cdkl5 KO mice was not associated with a worsening of neuroanatomical alterations, such as decreased dendritic arborization or spine density, but was paralleled by decreased neuronal survival in different brain regions such as the hippocampus, cortex, and basal ganglia. Interestingly, we found increased β-galactosidase activity and DNA repair protein levels, γH2AX and XRCC5, in the brains of older Cdkl5 KO mice, which suggests that an absence of Cdkl5 accelerates neuronal senescence/death by triggering irreparable DNA damage. In summary, this work provides evidence that CDKL5 may play a fundamental role in neuronal survival during brain aging and suggests a possible worsening with age of the clinical picture in CDD patients.
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Affiliation(s)
- Laura Gennaccaro
- 1Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Claudia Fuchs
- 1Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Manuela Loi
- 1Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Riccardo Pizzo
- 2Department of Neuroscience, University of Turin, Turin, Italy
| | - Sara Alvente
- 1Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Chiara Berteotti
- 1Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Leonardo Lupori
- 3BIO@SNS lab, Scuola Normale Superiore di Pisa, Pisa, Italy.,4Institute of Neuroscience, National Research Council, Pisa, Italy
| | - Giulia Sagona
- 4Institute of Neuroscience, National Research Council, Pisa, Italy.,5Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, Florence, Italy.,6Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa, Italy
| | - Giuseppe Galvani
- 1Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Antonia Gurgone
- 2Department of Neuroscience, University of Turin, Turin, Italy
| | | | - Giorgio Medici
- 1Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Marianna Tassinari
- 1Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Stefania Trazzi
- 1Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Elisa Ren
- 1Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Roberto Rimondini
- 7Department of Medical and Clinical Sciences, University of Bologna, Bologna, Italy
| | - Tommaso Pizzorusso
- 3BIO@SNS lab, Scuola Normale Superiore di Pisa, Pisa, Italy.,4Institute of Neuroscience, National Research Council, Pisa, Italy.,5Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA, University of Florence, Florence, Italy
| | - Zoccoli Giovanna
- 1Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Giustetto Maurizio
- 2Department of Neuroscience, University of Turin, Turin, Italy.,8National Institute of Neuroscience-Italy, Turin, Italy
| | - Ciani Elisabetta
- 1Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
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4
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Lupori L, Sagona G, Fuchs C, Mazziotti R, Stefanov A, Putignano E, Napoli D, Strettoi E, Ciani E, Pizzorusso T. Site-specific abnormalities in the visual system of a mouse model of CDKL5 deficiency disorder. Hum Mol Genet 2020; 28:2851-2861. [PMID: 31108505 PMCID: PMC6736061 DOI: 10.1093/hmg/ddz102] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 05/10/2019] [Accepted: 05/13/2019] [Indexed: 12/12/2022] Open
Abstract
CDKL5 deficiency disorder (CDD) is a neurodevelopmental disorder characterized by a severe global developmental delay and early-onset seizures. Notably, patients show distinctive visual abnormalities often clinically diagnosed as cortical visual impairment. However, the involvement of cerebral cortical dysfunctions in the origin of the symptoms is poorly understood. CDD mouse models also display visual deficits, and cortical visual responses can be used as a robust biomarker in CDKL5 mutant mice. A deeper understanding of the circuits underlying the described visual deficits is essential for directing preclinical research and translational approaches. Here, we addressed this question in two ways: first, we performed an in-depth morphological analysis of the visual pathway, from the retina to the primary visual cortex (V1), of CDKL5 null mice. We found that the lack of CDKL5 produced no alteration in the organization of retinal circuits. Conversely, CDKL5 mutants showed reduced density and altered morphology of spines and decreased excitatory synapse marker PSD95 in the dorsal lateral geniculate nucleus and in V1. An increase in the inhibitory marker VGAT was selectively present in V1. Second, using a conditional CDKL5 knockout model, we showed that selective cortical deletion of CDKL5 from excitatory cells is sufficient to produce abnormalities of visual cortical responses, demonstrating that the normal function of cortical circuits is dependent on CDKL5. Intriguingly, these deficits were associated with morphological alterations of V1 excitatory and inhibitory synaptic contacts. In summary, this work proposes cortical circuit structure and function as a critically important target for studying CDD.
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Affiliation(s)
- Leonardo Lupori
- BIO@SNS Laboratory, Scuola Normale Superiore, Via Moruzzi 1, Pisa 56124, Italy.,Institute of Neuroscience, National Research Council, Via Moruzzi 1, Pisa 56124, Italy
| | - Giulia Sagona
- Institute of Neuroscience, National Research Council, Via Moruzzi 1, Pisa 56124, Italy.,Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA University of Florence, Area San Salvi-Pad. 26, Florence 50135, Italy.,Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa 56128, Italy
| | - Claudia Fuchs
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna 40126, Italy
| | - Raffaele Mazziotti
- Institute of Neuroscience, National Research Council, Via Moruzzi 1, Pisa 56124, Italy.,Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA University of Florence, Area San Salvi-Pad. 26, Florence 50135, Italy
| | - Antonia Stefanov
- Institute of Neuroscience, National Research Council, Via Moruzzi 1, Pisa 56124, Italy
| | - Elena Putignano
- Institute of Neuroscience, National Research Council, Via Moruzzi 1, Pisa 56124, Italy
| | - Debora Napoli
- BIO@SNS Laboratory, Scuola Normale Superiore, Via Moruzzi 1, Pisa 56124, Italy.,Institute of Neuroscience, National Research Council, Via Moruzzi 1, Pisa 56124, Italy
| | - Enrica Strettoi
- Institute of Neuroscience, National Research Council, Via Moruzzi 1, Pisa 56124, Italy
| | - Elisabetta Ciani
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna 40126, Italy
| | - Tommaso Pizzorusso
- BIO@SNS Laboratory, Scuola Normale Superiore, Via Moruzzi 1, Pisa 56124, Italy.,Institute of Neuroscience, National Research Council, Via Moruzzi 1, Pisa 56124, Italy.,Department of Neuroscience, Psychology, Drug Research and Child Health NEUROFARBA University of Florence, Area San Salvi-Pad. 26, Florence 50135, Italy
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5
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CDKL5 Deficiency Disorder-A Complex Epileptic Encephalopathy. Brain Sci 2020; 10:brainsci10020107. [PMID: 32079229 PMCID: PMC7071516 DOI: 10.3390/brainsci10020107] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 02/11/2020] [Accepted: 02/13/2020] [Indexed: 12/31/2022] Open
Abstract
CDKL5 deficiency disorder (CDD) is a complex of clinical symptoms resulting from the presence of non-functional CDKL5 protein, i.e., serine-threonine kinase (previously referred to as STK9), or its complete absence. The clinical picture is characterized by epileptic seizures (that start within the first three months of life and most often do not respond to pharmacological treatment), epileptic encephalopathy secondary to seizures, and retardation of psychomotor development, which are often observed already in the first months of life. Due to the fact that CDKL5 is located on the X chromosome, the prevalence of CDD among women is four times higher than in men. However, the course is usually more severe among male patients. Recently, many clinical centers have analyzed this condition and provided knowledge on the function of CDKL5 protein, the natural history of the disease, therapeutic options, and their effectiveness and prognosis. The International CDKL5 Disorder Database was established in 2012, which focuses its activity on expanding knowledge related to this condition and disseminating such knowledge to the families of patients.
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6
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Changes in Calcium Homeostasis and Gene Expression Implicated in Epilepsy in Hippocampi of Mice Overexpressing ORAI1. Int J Mol Sci 2019; 20:ijms20225539. [PMID: 31698854 PMCID: PMC6888010 DOI: 10.3390/ijms20225539] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/04/2019] [Accepted: 11/04/2019] [Indexed: 12/21/2022] Open
Abstract
Previously, we showed that the overexpression of ORAI1 calcium channel in neurons of murine brain led to spontaneous occurrence of seizure-like events in aged animals of transgenic line FVB/NJ-Tg(ORAI1)Ibd (Nencki Institute of Experimental Biology). We aimed to identify the mechanism that is responsible for this phenomenon. Using a modified Ca2+-addback assay in the CA1 region of acute hippocampal slices and FURA-2 acetomethyl ester (AM) Ca2+ indicator, we found that overexpression of ORAI1 in neurons led to altered Ca2+ response. Next, by RNA sequencing (RNAseq) we identified a set of genes, whose expression was changed in our transgenic animals. These data were validated using customized real-time PCR assays and digital droplet PCR (ddPCR) ddPCR. Using real-time PCR, up-regulation of hairy and enhancer of split-5 (Hes-5) gene and down-regulation of aristaless related homeobox (Arx), doublecortin-like kinase 1 (Dclk1), and cyclin-dependent kinase-like 5 (Cdkl5, also known as serine/threonine kinase 9 (Stk9)) genes were found. Digital droplet PCR (ddPCR) analysis revealed down-regulation of Arx. In humans, ARX, DCLK1, and CDLK5 were shown to be mutated in some rare epilepsy-associated disorders. We conclude that the occurrence of seizure-like events in aged mice overexpressing ORAI1 might be due to the down-regulation of Arx, and possibly of Cdkl5 and Dclk1 genes.
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7
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Liang JS, Huang H, Wang JS, Lu JF. Phenotypic manifestations between male and female children with CDKL5 mutations. Brain Dev 2019; 41:783-789. [PMID: 31122804 DOI: 10.1016/j.braindev.2019.05.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 04/17/2019] [Accepted: 05/07/2019] [Indexed: 12/29/2022]
Abstract
BACKGROUND Cyclin-dependent kinase-like 5 (CDKL5), which maps to chromosome Xp22.13 and contains 20 coding exons, has been recognized as the gene responsible for early-onset epileptic encephalopathy (EoEE). A retrospective study is carried out to analyze potential genotypic and phenotypic differences between male and female patients with CDKL5 mutations. MATERIALS AND METHODS Targeted next-generation DNA sequencing was employed to search for mutations in patients with cryptogenic EE. A total of 44 patients with EoEE/infantile spasms (ISs)/West syndrome were enrolled for pathogenic mutation screening. The clinical phenotypes of patients with CDKL5 mutations were analyzed and compared with those of 166 published cases. RESULTS One novel and three recurrent mutations were found in four enrolled patients (two boys and two girls). One female patient had partial seizures during the early infantile period and epileptic spasms and tonic seizures several weeks thereafter. The other female patient had IS with hypsarrhythmia. The two male patients had IS without typical hypsarrhythmia and were bedridden. Brain MRIs of the male patients revealed brain atrophy and white matter hyperintensity. The female patients exhibited autistic features with hand stereotypies. CONCLUSION Our study highlights that both girls and boys with IS harbor CDKL5 mutations. Male children with CDKL5 mutations demonstrate a higher frequency of infantile spasms and brain atrophy, whereas female children often exhibit atypical Rett syndrome with EoEE. In addition, male children have a more severe phenotype than female children.
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Affiliation(s)
- Jao-Shwann Liang
- Department of Pediatrics, Far Eastern Memorial Hospital, New Taipei City, Taiwan; School of Medicine, National Yang-Ming University, Taipei, Taiwan; Department of Nursing, Oriental Institute of Technology, New Taipei City, Taiwan
| | - Hsin Huang
- School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Jinn-Shyan Wang
- School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Jyh-Feng Lu
- School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan.
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8
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Olson HE, Demarest ST, Pestana-Knight EM, Swanson LC, Iqbal S, Lal D, Leonard H, Cross JH, Devinsky O, Benke TA. Cyclin-Dependent Kinase-Like 5 Deficiency Disorder: Clinical Review. Pediatr Neurol 2019; 97:18-25. [PMID: 30928302 PMCID: PMC7120929 DOI: 10.1016/j.pediatrneurol.2019.02.015] [Citation(s) in RCA: 137] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 01/21/2019] [Accepted: 02/16/2019] [Indexed: 01/08/2023]
Abstract
Cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder (CDD) is a developmental encephalopathy caused by pathogenic variants in the gene CDKL5. This unique disorder includes early infantile onset refractory epilepsy, hypotonia, developmental intellectual and motor disabilities, and cortical visual impairment. We review the clinical presentations and genetic variations in CDD based on a systematic literature review and experience in the CDKL5 Centers of Excellence. We propose minimum diagnostic criteria. Pathogenic variants include deletions, truncations, splice variants, and missense variants. Pathogenic missense variants occur exclusively within the kinase domain or affect splice sites. The CDKL5 protein is widely expressed in the brain, predominantly in neurons, with roles in cell proliferation, neuronal migration, axonal outgrowth, dendritic morphogenesis, and synapse development. The molecular biology of CDD is revealing opportunities in precision therapy, with phase 2 and 3 clinical trials underway or planned to assess disease specific and disease modifying treatments.
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Affiliation(s)
- Heather E Olson
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Boston, Massachusetts.
| | - Scott T Demarest
- Children's Hospital Colorado, University of Colorado, School of Medicine, Aurora, Colorado; Department of Pediatrics, University of Colorado, School of Medicine, Aurora, Colorado
| | - Elia M Pestana-Knight
- Cleveland Clinic Neurological Institute Epilepsy Center, Cleveland Clinic Neurological Institute Pediatric Neurology Department, Neurogenetics, Cleveland Clinic Children's, Cleveland, Ohio
| | - Lindsay C Swanson
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Boston, Massachusetts
| | - Sumaiya Iqbal
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts; Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, Massachusetts
| | - Dennis Lal
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts; Genomic Medicine Institute, Cleveland Clinic, Cleveland, Ohio; Neurological Institute, Cleveland Clinic, Cleveland, Ohio
| | - Helen Leonard
- Telethon Kids Institute, University of Western Australia, Perth, WA, Australia
| | - J Helen Cross
- UCL Great Ormond Street NIHR BRC Institute of Child Health, London, UK
| | - Orrin Devinsky
- Department of Neurology, NYU Langone Health, New York, New York
| | - Tim A Benke
- Children's Hospital Colorado, University of Colorado, School of Medicine, Aurora, Colorado; Department of Pediatrics, University of Colorado, School of Medicine, Aurora, Colorado; Department of Pharmacology, University of Colorado, School of Medicine, Aurora, Colorado; Department of Neurology, University of Colorado, School of Medicine, Aurora, Colorado; Department of Otolaryngology, University of Colorado, School of Medicine, Aurora, Colorado
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9
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Ren E, Roncacé V, Trazzi S, Fuchs C, Medici G, Gennaccaro L, Loi M, Galvani G, Ye K, Rimondini R, Aicardi G, Ciani E. Functional and Structural Impairments in the Perirhinal Cortex of a Mouse Model of CDKL5 Deficiency Disorder Are Rescued by a TrkB Agonist. Front Cell Neurosci 2019; 13:169. [PMID: 31114483 PMCID: PMC6503158 DOI: 10.3389/fncel.2019.00169] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 04/09/2019] [Indexed: 11/24/2022] Open
Abstract
Cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder (CDD) is a severe X-linked neurodevelopmental encephalopathy caused by mutations in the CDKL5 gene and characterized by early-onset epilepsy and intellectual and motor impairments. No cure is currently available for CDD patients, as limited knowledge of the pathology has hindered the development of therapeutics. Cdkl5 knockout (KO) mouse models, recently created to investigate the role of CDKL5 in the etiology of CDD, recapitulate various features of the disorder. Previous studies have shown alterations in synaptic plasticity and dendritic pattern in the cerebral cortex and in the hippocampus, but the knowledge of the molecular substrates underlying these alterations is still limited. Here, we have examined for the first time synaptic function and plasticity, dendritic morphology, and signal transduction pathways in the perirhinal cortex (PRC) of this mouse model. Being interconnected with a wide range of cortical and subcortical structures and involved in various cognitive processes, PRC provides a very interesting framework for examining how CDKL5 mutation leads to deficits at the synapse, circuit, and behavioral level. We found that long-term potentiation (LTP) was impaired, and that the TrkB/PLCγ1 pathway could be mechanistically involved in this alteration. PRC neurons in mutant mice showed a reduction in dendritic length, dendritic branches, PSD-95-positive puncta, GluA2-AMPA receptor levels, and spine density and maturation. These functional and structural deficits were associated with impairment in visual recognition memory. Interestingly, an in vivo treatment with a TrkB agonist (the 7,8-DHF prodrug R13) to trigger the TrkB/PLCγ1 pathway rescued defective LTP, dendritic pattern, PSD-95 and GluA2-AMPA receptor levels, and restored visual recognition memory in Cdkl5 KO mice. Present findings demonstrate a critical role of TrkB signaling in the synaptic development alterations due to CDKL5 mutation, and suggest the possibility of TrkB-targeted pharmacological interventions.
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Affiliation(s)
- Elisa Ren
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Vincenzo Roncacé
- Department for Life Quality Studies, University of Bologna, Bologna, Italy
| | - Stefania Trazzi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Claudia Fuchs
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Giorgio Medici
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Laura Gennaccaro
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Manuela Loi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Giuseppe Galvani
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Keqiang Ye
- School of Medicine, Emory University, Atlanta, GA, United States
| | - Roberto Rimondini
- Department of Biomedical and Clinical Sciences, University of Bologna, Bologna, Italy
| | - Giorgio Aicardi
- Department for Life Quality Studies, University of Bologna, Bologna, Italy.,Interdepartmental Center "Luigi Galvani" for Integrated Studies of Bioinformatics, Biophysics and Biocomplexity, University of Bologna, Bologna, Italy
| | - Elisabetta Ciani
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
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10
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Mazziotti R, Lupori L, Sagona G, Gennaro M, Della Sala G, Putignano E, Pizzorusso T. Searching for biomarkers of CDKL5 disorder: early-onset visual impairment in CDKL5 mutant mice. Hum Mol Genet 2017; 26:2290-2298. [PMID: 28369421 PMCID: PMC5458338 DOI: 10.1093/hmg/ddx119] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Accepted: 03/25/2017] [Indexed: 01/03/2023] Open
Abstract
CDKL5 disorder is a neurodevelopmental disorder still without a cure. Murine models of CDKL5 disorder have been recently generated raising the possibility of preclinical testing of treatments. However, unbiased, quantitative biomarkers of high translational value to monitor brain function are still missing. Moreover, the analysis of treatment is hindered by the challenge of repeatedly and non-invasively testing neuronal function. We analyzed the development of visual responses in a mouse model of CDKL5 disorder to introduce visually evoked responses as a quantitative method to assess cortical circuit function. Cortical visual responses were assessed in CDKL5 null male mice, heterozygous females, and their respective control wild-type littermates by repeated transcranial optical imaging from P27 until P32. No difference between wild-type and mutant mice was present at P25-P26 whereas defective responses appeared from P27-P28 both in heterozygous and homozygous CDKL5 mutant mice. These results were confirmed by visually evoked potentials (VEPs) recorded from the visual cortex of a different cohort. The previously imaged mice were also analyzed at P60-80 using VEPs, revealing a persistent reduction of response amplitude, reduced visual acuity and defective contrast function. The level of adult impairment was significantly correlated with the reduction in visual responses observed during development. Support vector machine showed that multi-dimensional visual assessment can be used to automatically classify mutant and wt mice with high reliability. Thus, monitoring visual responses represents a promising biomarker for preclinical and clinical studies on CDKL5 disorder.
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Affiliation(s)
- Raffaele Mazziotti
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Area San Salvi - Pad. 26, 50135 Florence, Italy
| | - Leonardo Lupori
- BIO@SNS Lab, Scuola Normale Superiore via Moruzzi, 1?56124 Pisa, Italy
| | - Giulia Sagona
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Area San Salvi - Pad. 26, 50135 Florence, Italy
| | - Mariangela Gennaro
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Area San Salvi - Pad. 26, 50135 Florence, Italy.,Institute of Neuroscience, National Research Council, via Moruzzi, 1 56124 Pisa, Italy
| | - Grazia Della Sala
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Area San Salvi - Pad. 26, 50135 Florence, Italy.,Institute of Neuroscience, National Research Council, via Moruzzi, 1 56124 Pisa, Italy
| | - Elena Putignano
- Institute of Neuroscience, National Research Council, via Moruzzi, 1?56124 Pisa, Italy
| | - Tommaso Pizzorusso
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Area San Salvi - Pad. 26, 50135 Florence, Italy.,BIO@SNS Lab, Scuola Normale Superiore via Moruzzi, 1 56124 Pisa, Italy.,Institute of Neuroscience, National Research Council, via Moruzzi, 1 56124 Pisa, Italy
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11
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Parisi L, Di Filippo T, Roccella M. The Quality of Life in Girls with Rett Syndrome. Ment Illn 2016; 8:6302. [PMID: 27403274 PMCID: PMC4926033 DOI: 10.4081/mi.2016.6302] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 02/09/2016] [Accepted: 02/09/2016] [Indexed: 12/13/2022] Open
Abstract
Nowadays, quality of life is receiving an increasing attention in all scientific areas. Rett syndrome (RTT) is a rare neurological development, affecting mainly females. The congenital disease affects the central nervous system, and is one of the most common causes of severe intellectual disability. The aim of our study is to evaluate the effect of RTT on the quality of life of people who are affected. Both parents of 18 subjects, all female, diagnosed with RTT, took part in the research. Quality of life was assessed using the Italian version of the Impact of Childhood Illness Scale. This scale consists of 30 questions that investigate the effect of illness on children, parents and families. For each question, the parent was asked to rate two variables: frequency and importance. Another questionnaire was administered to obtain medical history, diagnostic and therapeutic data of the persons with RTT. Our data show that RTT has a considerable impact on both the child’s development and the entire family. Parents’ answers demonstrated that their child’s illness had consequences for the child and how the family coped with it. For this reason, attention should be directed at psychological and social aspects, as well as attitudes, manners, reactions and effects such disturbances can have on the entire family.
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Affiliation(s)
- Lucia Parisi
- Department of Psychological, Pedagogical and Educational Sciences, University of Palermo , Italy
| | - Teresa Di Filippo
- Department of Psychological, Pedagogical and Educational Sciences, University of Palermo , Italy
| | - Michele Roccella
- Department of Psychological, Pedagogical and Educational Sciences, University of Palermo , Italy
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Sivilia S, Mangano C, Beggiato S, Giuliani A, Torricella R, Baldassarro VA, Fernandez M, Lorenzini L, Giardino L, Borelli AC, Ferraro L, Calzà L. CDKL5 knockout leads to altered inhibitory transmission in the cerebellum of adult mice. GENES BRAIN AND BEHAVIOR 2016; 15:491-502. [DOI: 10.1111/gbb.12292] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 03/20/2016] [Accepted: 04/02/2016] [Indexed: 12/29/2022]
Affiliation(s)
- S. Sivilia
- Department of Veterinary Medical Science; University of Bologna; Bologna
| | - C. Mangano
- Department of Veterinary Medical Science; University of Bologna; Bologna
| | - S. Beggiato
- Department of Medical Sciences; University of Ferrara; Ferrara
| | - A. Giuliani
- Department of Veterinary Medical Science; University of Bologna; Bologna
| | - R. Torricella
- Health Science and Technologies Interdepartmental Center for Industrial Research (HST-ICIR); University of Bologna; Bologna
| | - V. A. Baldassarro
- Health Science and Technologies Interdepartmental Center for Industrial Research (HST-ICIR); University of Bologna; Bologna
| | - M. Fernandez
- Health Science and Technologies Interdepartmental Center for Industrial Research (HST-ICIR); University of Bologna; Bologna
| | - L. Lorenzini
- Health Science and Technologies Interdepartmental Center for Industrial Research (HST-ICIR); University of Bologna; Bologna
| | - L. Giardino
- Department of Veterinary Medical Science; University of Bologna; Bologna
- Health Science and Technologies Interdepartmental Center for Industrial Research (HST-ICIR); University of Bologna; Bologna
| | - A. C. Borelli
- Department of Medical Sciences; University of Ferrara; Ferrara
| | - L. Ferraro
- Department of Life Sciences and Biotechnology; University of Ferrara; Ferrara
| | - L. Calzà
- Department of Veterinary Medical Science; University of Bologna; Bologna
- Health Science and Technologies Interdepartmental Center for Industrial Research (HST-ICIR); University of Bologna; Bologna
- Department of Pharmacy and Biotechnology; University of Bologna; Bologna Italy
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13
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Mangatt M, Wong K, Anderson B, Epstein A, Hodgetts S, Leonard H, Downs J. Prevalence and onset of comorbidities in the CDKL5 disorder differ from Rett syndrome. Orphanet J Rare Dis 2016; 11:39. [PMID: 27080038 PMCID: PMC4832563 DOI: 10.1186/s13023-016-0418-y] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 03/30/2016] [Indexed: 11/27/2022] Open
Abstract
Background Initially described as an early onset seizure variant of Rett syndrome, the CDKL5 disorder is now considered as an independent entity. However, little is currently known about the full spectrum of comorbidities that affect these patients and available literature is limited to small case series. This study aimed to use a large international sample to examine the prevalence in this disorder of comorbidities of epilepsy, gastrointestinal problems including feeding difficulties, sleep and respiratory problems and scoliosis and their relationships with age and genotype. Prevalence and onset were also compared with those occurring in Rett syndrome. Methods Data for the CDKL5 disorder and Rett syndrome were sourced from the International CDKL5 Disorder Database (ICDD), InterRett and the Australian Rett syndrome Database (ARSD). Logistic regression (multivariate and univariate) was used to analyse the relationships between age group, mutation type and the prevalence of various comorbidities. Binary longitudinal data from the ARSD and the equivalent cross-sectional data from ICDD were examined using generalized linear models with generalized estimating equations. The Kaplan-Meier method was used to estimate the failure function for the two disorders and the log-rank test was used to compare the two functions. Results The likelihood of experiencing epilepsy, GI problems, respiratory problems, and scoliosis in the CDKL5 disorder increased with age and males were more vulnerable to respiratory and sleep problems than females. We did not identify any statistically significant relationships between mutation group and prevalence of comorbidities. Epilepsy, GI problems and sleep abnormalities were more common in the CDKL5 disorder than in Rett syndrome whilst scoliosis and respiratory problems were less prevalent. Conclusion This study captured a much clearer picture of the CDKL5 disorder than previously possible using the largest sample available to date. There were differences in the presentation of clinical features occurring in the CDKL5 disorder and in Rett syndrome, reinforcing the concept that CDKL5 is an independent disorder with its own distinctive characteristics.
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Affiliation(s)
- Meghana Mangatt
- Telethon Kids Institute, The University of Western Australia, Perth, WA, Australia.,School of Anatomy, Physiology & Human Biology, the University of Western Australia, Perth, WA, Australia
| | - Kingsley Wong
- Telethon Kids Institute, The University of Western Australia, Perth, WA, Australia
| | - Barbara Anderson
- Telethon Kids Institute, The University of Western Australia, Perth, WA, Australia
| | - Amy Epstein
- Telethon Kids Institute, The University of Western Australia, Perth, WA, Australia
| | - Stuart Hodgetts
- School of Anatomy, Physiology & Human Biology, the University of Western Australia, Perth, WA, Australia.,Western Australian Neuroscience Research Institute, Perth, WA, Australia
| | - Helen Leonard
- Telethon Kids Institute, The University of Western Australia, Perth, WA, Australia.
| | - Jenny Downs
- Telethon Kids Institute, The University of Western Australia, Perth, WA, Australia.,School of Physiotherapy and Exercise Science, Curtin University, Perth, WA, Australia
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Fehr S, Leonard H, Ho G, Williams S, de Klerk N, Forbes D, Christodoulou J, Downs J. There is variability in the attainment of developmental milestones in the CDKL5 disorder. J Neurodev Disord 2015; 7:2. [PMID: 25657822 PMCID: PMC4318547 DOI: 10.1186/1866-1955-7-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 12/16/2014] [Indexed: 11/29/2022] Open
Abstract
Background Individuals with the CDKL5 disorder have been described as having severely impaired development. A few individuals have been reported having attained more milestones including walking and running. Our aim was to investigate variation in attainment of developmental milestones and associations with underlying genotype. Methods Data was sourced from the International CDKL5 Disorder Database, and individuals were included if they had a pathogenic or probably pathogenic CDKL5 mutation and information on early development. Kaplan-Meier time-to-event analyses investigated the occurrence of developmental milestones. Mutations were grouped by their structural/functional consequence, and Cox regression was used to investigate the relationship between genotype and milestone attainment. Results The study included 109 females and 18 males. By 5 years of age, only 75% of the females had attained independent sitting and 25% independent walking whilst a quarter of the males could sit independently by 1 year 3 months. Only one boy could walk independently. No clear relationship between mutation group and milestone attainment was present, although females with a late truncating mutation attained the most milestones. Conclusion Attainment of developmental milestones is severely impaired in the CDKL5 disorder, with the majority who did attain skills attaining them at a late age. It appears as though males are more severely impaired than the females. Larger studies are needed to further investigate the role of genotype on clinical variability.
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Affiliation(s)
- Stephanie Fehr
- Telethon Kids Institute, University of Western Australia, Perth, Western Australia Australia
| | - Helen Leonard
- Telethon Kids Institute, University of Western Australia, Perth, Western Australia Australia
| | - Gladys Ho
- Western Sydney Genetics Program, Children's Hospital at Westmead, Sydney, NSW Australia
| | - Simon Williams
- Department of Neurology and Rehabilitation, Princess Margaret Hospital, Perth, Western Australia Australia
| | - Nick de Klerk
- Telethon Kids Institute, University of Western Australia, Perth, Western Australia Australia
| | - David Forbes
- School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia Australia
| | - John Christodoulou
- Western Sydney Genetics Program, Children's Hospital at Westmead, Sydney, NSW Australia ; Disciplines of Paediatrics & Child Health and Genetic Medicine, University of Sydney, Sydney, NSW Australia
| | - Jenny Downs
- Telethon Kids Institute, University of Western Australia, Perth, Western Australia Australia ; School of Physiotherapy and Exercise Science, Curtin University, Perth, Western Australia Australia
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15
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Deng H, Zheng W, Song Z. Genetics, Molecular Biology, and Phenotypes of X-Linked Epilepsy. Mol Neurobiol 2013; 49:1166-80. [DOI: 10.1007/s12035-013-8589-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Accepted: 11/05/2013] [Indexed: 11/25/2022]
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Paine SML, Munot P, Carmichael J, Das K, Weber MA, Prabhakar P, Jacques TS. The neuropathological consequences ofCDKL5mutation. Neuropathol Appl Neurobiol 2012; 38:744-7. [DOI: 10.1111/j.1365-2990.2012.01292.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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The CDKL5 disorder is an independent clinical entity associated with early-onset encephalopathy. Eur J Hum Genet 2012; 21:266-73. [PMID: 22872100 DOI: 10.1038/ejhg.2012.156] [Citation(s) in RCA: 193] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The clinical understanding of the CDKL5 disorder remains limited, with most information being derived from small patient groups seen at individual centres. This study uses a large international data collection to describe the clinical profile of the CDKL5 disorder and compare with Rett syndrome (RTT). Information on individuals with cyclin-dependent kinase-like 5 (CDKL5) mutations (n=86) and females with MECP2 mutations (n=920) was sourced from the InterRett database. Available photographs of CDKL5 patients were examined for dysmorphic features. The proportion of CDKL5 patients meeting the recent Neul criteria for atypical RTT was determined. Logistic regression and time-to-event analyses were used to compare the occurrence of Rett-like features in those with MECP2 and CDKL5 mutations. Most individuals with CDKL5 mutations had severe developmental delay from birth, seizure onset before the age of 3 months and similar non-dysmorphic features. Less than one-quarter met the criteria for early-onset seizure variant RTT. Seizures and sleep disturbances were more common than in those with MECP2 mutations whereas features of regression and spinal curvature were less common. The CDKL5 disorder presents with a distinct clinical profile and a subtle facial, limb and hand phenotype that may assist in differentiation from other early-onset encephalopathies. Although mutations in the CDKL5 gene have been described in association with the early-onset variant of RTT, in our study the majority did not meet these criteria. Therefore, the CDKL5 disorder should be considered separate to RTT, rather than another variant.
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Maortua H, Martínez-Bouzas C, Calvo MT, Domingo MR, Ramos F, García-Ribes A, Martínez MJ, López-Aríztegui MA, Puente N, Rubio I, Tejada MI. CDKL5 gene status in female patients with epilepsy and Rett-like features: two new mutations in the catalytic domain. BMC MEDICAL GENETICS 2012; 13:68. [PMID: 22867051 PMCID: PMC3489578 DOI: 10.1186/1471-2350-13-68] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 07/25/2012] [Indexed: 11/10/2022]
Abstract
BACKGROUND Mutations in the cyclin-dependent kinase-like 5 gene (CDKL5) located in the Xp22 region have been shown to cause a subset of atypical Rett syndrome with infantile spasms or early seizures starting in the first postnatal months. METHODS We performed mutation screening of CDKL5 in 60 female patients who had been identified as negative for the methyl CpG-binding protein 2 gene (MECP2) mutations, but who had current or past epilepsy, regardless of the age of onset, type, and severity. All the exons in the CDKL5 gene and their neighbouring sequences were examined, and CDKL5 rearrangements were studied by multiplex ligation-dependent probe amplification (MLPA). RESULTS Six previously unidentified DNA changes were detected, two of which were disease-causing mutations in the catalytic domain: a frameshift mutation (c.509_510insGT; p.Glu170GlyfsX36) and a complete deletion of exon 10. Both were found in patients with seizures that started in the first month of life. CONCLUSIONS This study demonstrated the importance of CDKL5 mutations as etiological factors in neurodevelopmental disorders, and indicated that a thorough analysis of the CDKL5 gene sequence and its rearrangements should be considered in females with Rett syndrome-like phenotypes, severe encephalopathy and epilepsy with onset before 5 months of age. This study also confirmed the usefulness of MLPA as a diagnostic screening method for use in clinical practice.
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Affiliation(s)
- Hiart Maortua
- Laboratorio de Genética Molecular, Servicio de Genética, Hospital Universitario Cruces, Instituto BioCruces, Barakaldo-Bizkaia, Spain
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What we know and would like to know about CDKL5 and its involvement in epileptic encephalopathy. Neural Plast 2012; 2012:728267. [PMID: 22779007 PMCID: PMC3385648 DOI: 10.1155/2012/728267] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 04/06/2012] [Indexed: 12/11/2022] Open
Abstract
In the last few years, the X-linked serine/threonine kinase cyclin-dependent kinase-like 5 (CDKL5) has been associated with early-onset epileptic encephalopathies characterized by the manifestation of intractable epilepsy within the first weeks of life, severe developmental delay, profound hypotonia, and often the presence of some Rett-syndrome-like features. The association of CDKL5 with neurodevelopmental disorders and its high expression levels in the maturing brain underscore the importance of this kinase for proper brain development. However, our present knowledge of CDKL5 functions is still rather limited. The picture that emerges from the molecular and cellular studies suggests that CDKL5 functions are important for regulating both neuronal morphology through cytoplasmic signaling pathways and activity-dependent gene expression in the nuclear compartment. This paper surveys the current state of CDKL5 research with emphasis on the clinical symptoms associated with mutations in CDKL5, the different mechanisms regulating its functions, and the connected molecular pathways. Finally, based on the available data we speculate that CDKL5 might play a role in neuronal plasticity and we adduce and discuss some possible arguments supporting this hypothesis.
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