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Kim SH, Kwon SS, Lee JS, Kim HD, Lee ST, Choi JR, Shin S, Kang HC. Analysis of trio test in neurodevelopmental disorders. Front Pediatr 2022; 10:1073083. [PMID: 36619507 PMCID: PMC9816327 DOI: 10.3389/fped.2022.1073083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 11/21/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Trio test has been widely used for diagnosis of various hereditary disorders. We aimed to investigate the contribution of trio test in genetically diagnosing neurodevelopmental disorders (NDD). METHODS We retrospectively reviewed 2,059 NDD cases with genetic test results. The trio test was conducted in 563 cases. Clinical usefulness, optimal timing, and methods for the trio test were reviewed. RESULTS Pathogenic or likely pathogenic variants were detected in 112 of 563 (19.9%) patients who underwent the trio test. With trio test results, the overall diagnostic yield increased by 5.4% (112/2,059). Of 165 de novo variants detected, 149 were pathogenic and we detected 85 novel pathogenic variants. Pathogenic, de novo variants were frequently detected in CDKL5, ATP1A3, and STXBP1. CONCLUSION The trio test is an efficient method for genetically diagnosing NDD. We identified specific situations where a certain trio test is more appropriate, thereby providing a guide for clinicians when confronted with variants of unknown significance of specific genes.
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Affiliation(s)
- Se Hee Kim
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, South Korea
| | - Soon Sung Kwon
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Joon Soo Lee
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, South Korea
| | - Heung Dong Kim
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, South Korea
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Jong Rak Choi
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Saeam Shin
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Hoon-Chul Kang
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, South Korea
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Serrano RJ, Lee C, Douek AM, Kaslin J, Bryson-Richardson RJ, Sztal TE. Novel pre-clinical model for CDKL5 Deficiency Disorder. Dis Model Mech 2021; 15:273746. [PMID: 34913468 PMCID: PMC8922025 DOI: 10.1242/dmm.049094] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Accepted: 12/06/2021] [Indexed: 11/20/2022] Open
Abstract
Cyclin-dependent kinase-like-5 (CDKL5) deficiency disorder (CDD) is a severe X-linked neurodegenerative disease characterised by early-onset epileptic seizures, low muscle tone, progressive intellectual disability and severe motor function. CDD affects ∼1 in 60,000 live births, with many patients experiencing a reduced quality of life due to the severity of their neurological symptoms and functional impairment. There are no effective therapies for CDD, with current treatments focusing on improving symptoms rather than addressing the underlying causes of the disorder. Zebrafish offer many unique advantages for high-throughput preclinical evaluation of potential therapies for neurological diseases, including CDD. In particular, the large number of offspring produced, together with the possibilities for in vivo imaging and genetic manipulation, allows for the detailed assessment of disease pathogenesis and therapeutic discovery. We have characterised a loss-of-function zebrafish model for CDD, containing a nonsense mutation in cdkl5. cdkl5 mutant zebrafish display defects in neuronal patterning, seizures, microcephaly, and reduced muscle function caused by impaired muscle innervation. This study provides a powerful vertebrate model for investigating CDD disease pathophysiology and allowing high-throughput screening for effective therapies. This article has an associated First Person interview with the first author of the paper. Summary: Characterisation of a novel loss-of-function zebrafish model for CDKL5 deficiency disorder, containing a nonsense mutation, demonstrates its utility for investigating disease aetiology and allowing high-throughput screening for potentially effective therapies.
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Affiliation(s)
- Rita J Serrano
- School of Biological Sciences, Monash University, Melbourne, Australia
| | - Clara Lee
- School of Biological Sciences, Monash University, Melbourne, Australia
| | - Alon M Douek
- Australian Regenerative Medicine Institute, Monash University, Melbourne, Australia
| | - Jan Kaslin
- Australian Regenerative Medicine Institute, Monash University, Melbourne, Australia
| | | | - Tamar E Sztal
- School of Biological Sciences, Monash University, Melbourne, Australia
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Siri B, Varesio C, Freri E, Darra F, Gana S, Mei D, Porta F, Fontana E, Galati G, Solazzi R, Niceta M, Veggiotti P, Alfei E. CDKL5 deficiency disorder in males: Five new variants and review of the literature. Eur J Paediatr Neurol 2021; 33:9-20. [PMID: 33989939 DOI: 10.1016/j.ejpn.2021.04.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 04/18/2021] [Accepted: 04/24/2021] [Indexed: 11/30/2022]
Abstract
The X-linked Cyclin-Dependent Kinase-Like 5 (CDKL5) gene encodes a serine-threonine kinase highly expressed in the developing brain. Loss of function of CDKL5 is pointed out to underlie the CDKL5 Deficiency Disorder (CDD), an X-linked dominant disease characterized by early-onset epileptic encephalopathy and developmental delay, usually affecting females more than males. To the best to our knowledge, only 45 males with CDD have been reported so far. Type and position of CDKL5 variants with different impact on the protein are reported to influence the clinical presentation. X-chromosome inactivation occurring in females and post-zygotic mosaicism in males are also believed to contribute to this variability. Based on these issues, genotype-phenotype correlations are still challenging. Here, we describe clinical features of five additional affected males with unreported CDKL5 variants, expanding the molecular spectrum of the disorder. We also reviewed the clinical profile of the previously reported 45 males with molecularly confirmed CDD. Severe developmental delay, cortical visual impairment, and early-onset refractory epilepsy characterize the CDD picture in males. By assessing the molecular spectrum, we confirm that germ-line truncating CDKL5 variants, equally distributed across the coding sequence, are the most recurrent mutations in CDD, and cause the worsen phenotype. While recurrence and relevance of missense substitutions within C-terminal remain still debated, disease-causing missense changes affecting the N-terminal catalytic domain correlate to a severe clinical phenotype. Finally, our data provide evidence that post-zygotic CDKL5 mosaicism may result in milder phenotypes and, at least in a subset of subjects, in variable response to antiepileptic treatments.
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Affiliation(s)
- Barbara Siri
- Department of Paediatrics, Ospedale Infantile Regina Margherita, University of Torino, Italy; Division of Metabolism, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Costanza Varesio
- Department of Child Neurology and Psychiatry, IRCCS Mondino Foundation, Italy; Department of Brain and Behavioral Sciences, University of Pavia, Italy.
| | - Elena Freri
- Department of Paediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Francesca Darra
- Child Neuropsychiatry, Department of Surgical Sciences, Dentistry, Gynecology and Paediatrics, University of Verona, AOUI Verona, Verona, Italy
| | - Simone Gana
- Medical Genetics Unit, IRCCS Mondino Foundation, Pavia, Italy
| | - Davide Mei
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Children's Hospital A. Meyer-University of Florence, Italy
| | - Francesco Porta
- Department of Paediatrics, AOU Città della Salute e della Scienza di Torino, University of Torino, Italy
| | - Elena Fontana
- Child Neuropsychiatry, Department of Surgical Sciences, Dentistry, Gynecology and Paediatrics, University of Verona, AOUI Verona, Verona, Italy
| | - Giulia Galati
- Child Neuropsychiatry, Department of Surgical Sciences, Dentistry, Gynecology and Paediatrics, University of Verona, AOUI Verona, Verona, Italy
| | - Roberta Solazzi
- Department of Paediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Marcello Niceta
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Pierangelo Veggiotti
- L. Sacco Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy; Paediatric Neurology Unit V. Buzzi Children's Hospital Milan, Italy
| | - Enrico Alfei
- Paediatric Neurology Unit V. Buzzi Children's Hospital Milan, Italy
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Kobayashi Y, Tohyama J, Takahashi Y, Goto T, Haginoya K, Inoue T, Kubota M, Fujita H, Honda R, Ito M, Kishimoto K, Nakamura K, Sakai Y, Takanashi JI, Tanaka M, Tanda K, Tominaga K, Yoshioka S, Kato M, Nakashima M, Saitsu H, Matsumoto N. Clinical manifestations and epilepsy treatment in Japanese patients with pathogenic CDKL5 variants. Brain Dev 2021; 43:505-514. [PMID: 33436160 DOI: 10.1016/j.braindev.2020.12.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 11/12/2020] [Accepted: 12/15/2020] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Patients with pathogenic cyclin-dependent kinase-like-5 gene (CDKL5) variants are designated CDKL5 deficiency disorder (CDD). This study aimed to delineate the clinical characteristics of Japanese patients with CDD and elucidate possible appropriate treatments. METHODS We recruited patients with pathogenic or likely pathogenic CDKL5 variants from a cohort of approximately 1,100 Japanese patients with developmental and epileptic encephalopathies, who underwent genetic analysis. We retrospectively reviewed clinical, electroencephalogram, neuroimaging, and genetic information. RESULTS We identified 29 patients (21 females, eight males). All patients showed severe developmental delay, especially in males. Involuntary movements were observed in 15 patients. No antiepileptic drugs (AEDs) achieved seizure freedom by monotherapy. AEDs achieving ≥ 50% reduction in seizure frequency were sodium valproate in two patients, vigabatrin in one, and lamotrigine in one. Seizure aggravation was observed during the use of lamotrigine, potassium bromide, and levetiracetam. Adrenocorticotrophic hormone (ACTH) was the most effective treatment. The ketogenic diet (KD), corpus callosotomy and vagus nerve stimulation did not improve seizure frequency in most patients, but KD was remarkably effective in one. The degree of brain atrophy on magnetic resonance imaging (MRI) reflected disease severity. Compared with females, males had lower levels of attained motor development and more severe cerebral atrophy on MRI. CONCLUSION Our patients showed more severe global developmental delay than those in previous studies and had intractable epilepsy, likely because previous studies had lower numbers of males. Further studies are needed to investigate appropriate therapy for CDD, such as AED polytherapy or combination treatment involving ACTH, KD, and AEDs.
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Affiliation(s)
- Yu Kobayashi
- Department of Child Neurology, NHO Nishiniigata Chuo Hospital, Niigata, Japan.
| | - Jun Tohyama
- Department of Child Neurology, NHO Nishiniigata Chuo Hospital, Niigata, Japan
| | - Yukitoshi Takahashi
- National Epilepsy Center, NHO Shizuoka Institute of Epilepsy and Neurological Disorders, Shizuoka, Japan
| | - Tomohide Goto
- Division of Neurology, Kanagawa Children's Medical Center, Yokohama, Japan
| | - Kazuhiro Haginoya
- Department of Pediatric Neurology, Miyagi Children's Hospital, Sendai, Japan
| | - Takeshi Inoue
- Department of Pediatric Neurology, Osaka City General Hospital, Osaka, Japan
| | - Masaya Kubota
- Division of Neurology, National Center for Child Health and Development, Tokyo, Japan
| | - Hiroshi Fujita
- Department of Pediatrics, NHO Aomori Hospital, Aomori, Japan
| | - Ryoko Honda
- Department of Pediatrics, National Hospital Organization Nagasaki Medical Center, Nagasaki, Japan
| | - Masahiro Ito
- Department of Pediatrics, Tokyo Metropolitan Bokutoh Hospital, Tokyo, Japan
| | - Kanako Kishimoto
- Department of Pediatrics, Osaka Hospital, Japan Community Healthcare Organization (JCHO), Osaka, Japan
| | - Kazuyuki Nakamura
- Department of Pediatrics, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Yasunari Sakai
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Jun-Ichi Takanashi
- Department of Pediatrics, Tokyo Women's Medical University Yachiyo Medical Center, Yachiyo, Japan
| | - Manabu Tanaka
- Division of General Pediatrics, Saitama Children's Medical Center, Saitama, Japan
| | - Koichi Tanda
- Department of Pediatrics, Japanese Red Cross Kyoto Daiichi Hospital, Kyoto, Japan
| | - Koji Tominaga
- Department of Pediatrics, Graduate School of Medicine, Osaka University, Suita, Japan
| | | | - Mitsuhiro Kato
- Department of Pediatrics, Showa University School of Medicine, Tokyo, Japan
| | - Mitsuko Nakashima
- Department of Biochemistry, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Hirotomo Saitsu
- Department of Biochemistry, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
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Hirose S, Tanaka Y, Shibata M, Kimura Y, Ishikawa M, Higurashi N, Yamamoto T, Ichise E, Chiyonobu T, Ishii A. Application of induced pluripotent stem cells in epilepsy. Mol Cell Neurosci 2020; 108:103535. [DOI: 10.1016/j.mcn.2020.103535] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 07/10/2020] [Accepted: 07/31/2020] [Indexed: 02/06/2023] Open
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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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Screen for reactivation of MeCP2 on the inactive X chromosome identifies the BMP/TGF-β superfamily as a regulator of XIST expression. Proc Natl Acad Sci U S A 2017; 114:1619-1624. [PMID: 28143937 DOI: 10.1073/pnas.1621356114] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Rett syndrome (RS) is a debilitating neurological disorder affecting mostly girls with heterozygous mutations in the gene encoding the methyl-CpG-binding protein MeCP2 on the X chromosome. Because restoration of MeCP2 expression in a mouse model reverses neurologic deficits in adult animals, reactivation of the wild-type copy of MeCP2 on the inactive X chromosome (Xi) presents a therapeutic opportunity in RS. To identify genes involved in MeCP2 silencing, we screened a library of 60,000 shRNAs using a cell line with a MeCP2 reporter on the Xi and found 30 genes clustered in seven functional groups. More than half encoded proteins with known enzymatic activity, and six were members of the bone morphogenetic protein (BMP)/TGF-β pathway. shRNAs directed against each of these six genes down-regulated X-inactive specific transcript (XIST), a key player in X-chromosome inactivation that encodes an RNA that coats the silent X chromosome, and modulation of regulators of this pathway both in cell culture and in mice demonstrated robust regulation of XIST. Moreover, we show that Rnf12, an X-encoded ubiquitin ligase important for initiation of X-chromosome inactivation and XIST transcription in ES cells, also plays a role in maintenance of the inactive state through regulation of BMP/TGF-β signaling. Our results identify pharmacologically suitable targets for reactivation of MeCP2 on the Xi and a genetic circuitry that maintains XIST expression and X-chromosome inactivation in differentiated cells.
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