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Chen Y, Liu A, Zhang X, Ma X, Sun D, Tian X, Wu W, Zeng Q, Jiang Y, Zhang Y. Seizure course of PCDH19 clustering epilepsy in female children: A multicentre cohort study in China. Dev Med Child Neurol 2024; 66:804-815. [PMID: 37960945 DOI: 10.1111/dmcn.15803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 10/09/2023] [Accepted: 10/17/2023] [Indexed: 11/15/2023]
Abstract
AIM To investigate the seizure course of PCDH19 clustering epilepsy (PCDH19-CE) in a cohort of female children in China. METHOD This ambidirectional cohort study examined 113 female patients with PCDH19-CE through multicentre collaboration. Prognostic factors for seizure freedom were evaluated by multivariate Cox regression analysis. RESULTS The median seizure course period from seizure onset was 6 years 6 months. Of 113 patients, 78% and 56% experienced seizure freedom for at least 1 year and at least 2 years respectively. In patients younger than 5 years (n = 30), 5 to 10 years (n = 52), and older than 10 years (n = 31), 57%, 81%, and 94% experienced at least 1 year of seizure freedom, and 32%, 52%, and 84% experienced at least 2 years of seizure freedom, respectively. However, 58% (65 out of 113) relapsed at least once after more than 1 year of seizure freedom without trigger exposure (40%) or because of common triggers, including fever (43%) and antiseizure medication (ASM) reduction (29%). There was an 84% risk of seizure relapse after ASM reduction attempts. The likelihood of seizure freedom decreased with early age at seizure onset and developmental delay. INTERPRETATION Patients with PCDH19-CE exhibit increasing seizure freedom with age, but there is a risk of relapse. ASM reduction in children younger than 10 years old requires caution. Patients with early seizure onset and developmental delay have a reduced chance of seizure freedom. WHAT THIS PAPER ADDS The seizure freedom rate in PCDH19 clustering epilepsy gradually increases with age. The disease course is characterized by relapsing-remitting seizures. Antiseizure medication reduction requires caution for patients younger than 10 years of age. Patients with early seizure onset and developmental delay are less likely to achieve seizure freedom.
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Affiliation(s)
- Yi Chen
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Aijie Liu
- Department of Pediatric Neurology, Capital Institute of Pediatrics, Beijing, China
| | - Xiaoli Zhang
- Department of Pediatrics, The Third Affiliated Hospital of Zheng Zhou University, Zhengzhou, China
| | - Xiuwei Ma
- Department of Neurology, Bayi Children's Hospital, General Military Hospital of Beijing, Beijing, China
| | - Dan Sun
- Department of Neurology, Wuhan Children's Hospital, Wuhan, China
| | - Xiaojuan Tian
- Department of Neurology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Wenjuan Wu
- Department of Neurology, Children's Hospital of Hebei Province, Shijiazhuang, China
| | - Qi Zeng
- Department of Neurology, Shenzhen Children's Hospital, Shenzhen, China
| | - Yuwu Jiang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yuehua Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
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Szalai R, Hadzsiev K, Till A, Fogarasi A, Bodo T, Buki G, Banfai Z, Bene J. NGS-Based Identification of Two Novel PCDH19 Mutations in Female Patients with Early-Onset Epilepsy. Int J Mol Sci 2024; 25:5732. [PMID: 38891919 PMCID: PMC11171991 DOI: 10.3390/ijms25115732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 05/20/2024] [Accepted: 05/22/2024] [Indexed: 06/21/2024] Open
Abstract
Developmental and epileptic encephalopathy-9 (DEE9) is characterized by seizure onset in infancy, mild to severe intellectual impairment, and psychiatric features and is caused by a mutation in the PCDH19 gene on chromosome Xq22. The rare, unusual X-linked type of disorder affects heterozygous females and mosaic males; transmitting males are unaffected. In our study, 165 patients with epilepsy were tested by Next Generation Sequencing (NGS)-based panel and exome sequencing using Illumina technology. PCDH19 screening identified three point mutations, one indel, and one 29 bp-long deletion in five unrelated female probands. Two novel mutations, c.1152_1180del (p.Gln385Serfs*6) and c.830_831delinsAA (p.Phe277*), were identified and found to be de novo pathogenic. Moreover, among the three inherited mutations, two originated from asymptomatic mothers and one from an affected father. The PCDH19 c.1682C>T and c.1711G>T mutations were present in the DNA samples of asymptomatic mothers. After targeted parental testing, X chromosome inactivation tests and Sanger sequencing were carried out for mosaicism examination on maternal saliva samples in the two asymptomatic PCDH19 mutation carrier subjects. Tissue mosaicism and X-inactivation tests were negative. Our results support the opportunity for reduced penetrance in DEE9 and contribute to expanding the genotype-phenotype spectrum of PCDH19-related epilepsy.
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Affiliation(s)
- Renata Szalai
- Department of Medical Genetics, University of Pecs Medical School, 7624 Pecs, Hungary; (R.S.); (K.H.); (A.T.); (G.B.); (Z.B.)
| | - Kinga Hadzsiev
- Department of Medical Genetics, University of Pecs Medical School, 7624 Pecs, Hungary; (R.S.); (K.H.); (A.T.); (G.B.); (Z.B.)
| | - Agnes Till
- Department of Medical Genetics, University of Pecs Medical School, 7624 Pecs, Hungary; (R.S.); (K.H.); (A.T.); (G.B.); (Z.B.)
| | - Andras Fogarasi
- Child Neurology Department, Bethesda Children’s Hospital, 1146 Budapest, Hungary; (A.F.); (T.B.)
- Andras Peto Faculty, Semmelweis University, 1125 Budapest, Hungary
| | - Timea Bodo
- Child Neurology Department, Bethesda Children’s Hospital, 1146 Budapest, Hungary; (A.F.); (T.B.)
| | - Gergely Buki
- Department of Medical Genetics, University of Pecs Medical School, 7624 Pecs, Hungary; (R.S.); (K.H.); (A.T.); (G.B.); (Z.B.)
| | - Zsolt Banfai
- Department of Medical Genetics, University of Pecs Medical School, 7624 Pecs, Hungary; (R.S.); (K.H.); (A.T.); (G.B.); (Z.B.)
| | - Judit Bene
- Department of Medical Genetics, University of Pecs Medical School, 7624 Pecs, Hungary; (R.S.); (K.H.); (A.T.); (G.B.); (Z.B.)
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杨 晓. [Sperm Mosaic Variants and Their Influence on the Offspring]. SICHUAN DA XUE XUE BAO. YI XUE BAN = JOURNAL OF SICHUAN UNIVERSITY. MEDICAL SCIENCE EDITION 2024; 55:535-541. [PMID: 38948294 PMCID: PMC11211766 DOI: 10.12182/20240560507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Indexed: 07/02/2024]
Abstract
Genomic mosaicism arising from mosaic variants is a phenomenon that describes the presence of a cell or cell populations with different genome compositions from the germline cells of an individual. It comprises all types of genetic variants. A large proportion of childhood genetic disorders are defined as being de novo, meaning that the disease-causing mutations are only detected in the proband, not in any of the parents. Population studies show that 80% of the de novo mutations arise from the paternal haplotype, that is, from paternal sperm mosaicism. This review provides a summary of the types and detection strategies of sperm mosaicism. In addition, it provides discussions on how recent studies demonstrated that genomic mosaic mutations in parents, especially those in the paternal sperms, could be inherited by the offspring and cause childhood disorders. According to the previous findings of the author's research team, sperm mosaicism derived from early embryogenesis and primordial germ cell stages can explain 5% to 20% of the de novo mutations related to clinical phenotypes and can serve as an important predictor of both rare and complex disorders. Sperm mosaicism shows great potential for clinical genetic diagnosis and consultations. Based on the published literature, the author suggests that, large-scale screening for de novo sperm mosaic mutations and population-based genetic screening should be conducted in future studies, which will greatly enhance the risk assessment in the offspring and effectively improve the genetic health at the population level. Implementation of direct sperm detection for de novo mutations will significantly increase the efficiency of the stratification of patient cohorts and improve recurrence risk assessment for future births. Future research in the field should be focused on the impact of environmental and lifestyle factors on the health of the offspring through sperms and their modeling of mutation signatures. In addition, targeted in vitro modeling of sperm mutations will also be a promising direction.
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Affiliation(s)
- 晓旭 杨
- 犹他大学 (盐湖城 UT 84112)University of Utah, Salt Lake City, UT 84112, USA
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Kowkabi S, Yavarian M, Kaboodkhani R, Mohammadi M, Shervin Badv R. PCDH19-clustering epilepsy, pathophysiology and clinical significance. Epilepsy Behav 2024; 154:109730. [PMID: 38521028 DOI: 10.1016/j.yebeh.2024.109730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 02/07/2024] [Accepted: 02/27/2024] [Indexed: 03/25/2024]
Abstract
PCDH19 clustering epilepsy (PCDH19-CE) is an X-linked epilepsy disorder associated with intellectual disability (ID) and behavioral disturbances, which is caused by PCDH19 gene variants. PCDH19 pathogenic variant leads to epilepsy in heterozygous females, not in hemizygous males and the inheritance pattern is unusual. The hypothesis of cellular interference was described as a key pathogenic mechanism. According to that, males do not develop the disease because of the uniform expression of PCDH19 (variant or wild type) unless they have a somatic variation. We conducted a literature review on PCDH19-CE pathophysiology and concluded that other significant mechanisms could contribute to pathogenesis including: asymmetric cell division and heterochrony, female-related allopregnanolone deficiency, altered steroid gene expression, decreased Gamma-aminobutyric acid receptor A (GABAA) function, and blood-brain barrier (BBB) dysfunction. Being aware of these mechanisms helps us when we should decide which therapeutic option is more suitable for which patient.
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Affiliation(s)
- Safoura Kowkabi
- Child Neurology Division and Children's Epilepsy Monitoring Unit, Children's Medical Centre, Tehran University of Medical Sciences, Tehran, Iran; Shiraz University of Medical Sciences, Shiraz, Iran.
| | - Majid Yavarian
- Hematology Research Center, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
| | | | - Mahmood Mohammadi
- Child Neurology Division and Children's Epilepsy Monitoring Unit, Children's Medical Centre, Tehran University of Medical Sciences, Tehran, Iran
| | - Reza Shervin Badv
- Child Neurology Division and Children's Epilepsy Monitoring Unit, Children's Medical Centre, Tehran University of Medical Sciences, Tehran, Iran
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Parmeggiani G, Minardi R, Boni A, Pruccoli J, Pini A, Licchetta L, Bisulli F, Graziano C, Seri M. A Male Child with Infantile Epilepsy due to a Mosaic Missense Variant of PCDH19. Mol Syndromol 2024; 15:114-118. [PMID: 38585543 PMCID: PMC10996345 DOI: 10.1159/000535144] [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: 05/04/2023] [Accepted: 11/09/2023] [Indexed: 04/09/2024] Open
Abstract
Background Pathogenic variants of PCDH19, located on the X-chromosome (Xq22.1), cause a rare epileptic encephalopathy with speech and development delay, seizures, behavioral and psychiatric problems. The specific underlying pathogenic mechanism is known as "cellular interference" that results in affected heterozygous females, normal hemizygous males and affected mosaic males but its functioning is not yet clear. Objectives Reporting new cases of affected males is considered useful to a deeper insight. Subject and Method We present the case of a three-year-old boy with early-onset seizures at 3 months of age, mild cognitive impairment, partial control of seizures with levetiracetam, normal brain imaging. Results The patient has a mosaic pathogenic variant c.698A>G (p.Asp233Gly) in PCDH19 assessed by Next Generation Sequencing analysis. We have compared his characteristics with the genotypes and phenotypes of 34 PCDH19 mosaic males earlier reported in the literature. Finally, we have summarized today's knowledge about phenotype-genotype correlation and pharmacological response in these patients. Conclusions Our report confirms that the clinical picture of mosaic affected males, resembling that of females, can show a wide variability in severity of disease and underlines a stringent need to improve therapeutic approaches and to collect data on long-term follow-up.
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Affiliation(s)
- Giulia Parmeggiani
- Dipartimento MeLabeT, AUSL della Romagna, Pievesestina di Cesena, Cesena, Italy
| | - Raffaella Minardi
- Department of Biomedical and Neuromotor Sciences, IRCCS Istituto delle Scienze Neurologiche di Bologna, University of Bologna, Bologna, Italy
| | - Antonella Boni
- Department of Biomedical and Neuromotor Sciences, IRCCS Istituto delle Scienze Neurologiche di Bologna, University of Bologna, Bologna, Italy
| | - Jacopo Pruccoli
- Department of Biomedical and Neuromotor Sciences, IRCCS Istituto delle Scienze Neurologiche di Bologna, University of Bologna, Bologna, Italy
| | - Antonella Pini
- Department of Biomedical and Neuromotor Sciences, IRCCS Istituto delle Scienze Neurologiche di Bologna, University of Bologna, Bologna, Italy
| | - Laura Licchetta
- Department of Biomedical and Neuromotor Sciences, IRCCS Istituto delle Scienze Neurologiche di Bologna, University of Bologna, Bologna, Italy
| | - Francesca Bisulli
- Department of Biomedical and Neuromotor Sciences, IRCCS Istituto delle Scienze Neurologiche di Bologna, University of Bologna, Bologna, Italy
| | - Claudio Graziano
- Dipartimento MeLabeT, AUSL della Romagna, Pievesestina di Cesena, Cesena, Italy
| | - Marco Seri
- Dipartimento di Genetica Medica, IRCCS Azienda Ospedaliero-Universitaria di Bologna, University of Bologna, Bologna, Italy
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Sun M, Li Q, Zhang Y, Cai Y, Dong Y, Shu J, Li D, Cai C. Identification of Two Variants c.2697A > C and c.3305A > C in USP7 by Analysis of Whole-Exome Sequencing in Chinese Patients with Hao-Fountain Syndrome. Glob Med Genet 2024; 11:13-19. [PMID: 38229971 PMCID: PMC10791489 DOI: 10.1055/s-0043-1778089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024] Open
Abstract
Background Variants of ubiquitin-specific protease 7 ( USP7 ) gene in humans are associated with a neurodevelopmental disorder-Hao-Fountain syndrome, its core symptoms including developmental delay, intellectual disability, and speech delay. Other variable symptoms can affect multiple systems. In present study, we report two patients with core features from two unrelated consanguineous families originating from the Tianjin Children's Hospital. Methods and Results Genomic DNA was extracted from the peripheral blood samples collected from the probands with their family members and whole-exome sequencing (WES) was used to detect the pathogenic genes in the probands. Suspected variants were subsequently validated by Sanger sequencing. In family 1, WES revealed that the proband carried the de novo variant c.2697A > C (p.Leu899Phe) in USP7 (NM_003470.3). In family 2, WES identified the variant c.3305A > C (p.Asn1102Thr) in USP7 (NM_003470.3) from the proband. Conclusion We reported two cases of Hao-Fountain syndrome caused by novel USP7 variants. In addition, we report the first case of mosaicism with a USP7 variant in Chinese family. Our findings demonstrate the importance of WES in diagnosis of genetic diseases and expands the USP7 variants spectrum in Hao-Fountain syndrome. Moreover, we summarize the cases caused by USP7 variants in the literature. Our study can provide a vital reference for the diagnosis of future cases.
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Affiliation(s)
- Mei Sun
- Graduate College of Tianjin Medical University, Tianjin Medical University, Tianjin, Peoples' Republic of China
| | - Qing Li
- Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, Peoples' Republic of China
- Department of Neurology, Tianjin Children's Hospital (Tianjin University Children's Hospital), Tianjin, Peoples' Republic of China
| | - Ying Zhang
- Graduate College of Tianjin Medical University, Tianjin Medical University, Tianjin, Peoples' Republic of China
| | - Yingzi Cai
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, Peoples' Republic of China
| | - Yan Dong
- Graduate College of Tianjin Medical University, Tianjin Medical University, Tianjin, Peoples' Republic of China
| | - Jianbo Shu
- Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, Peoples' Republic of China
- Tianjin Pediatric Research Institute, Tianjin Children's Hospital (Tianjin University Children's Hospital), Tianjin, Peoples' Republic of China
- Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Children Hosptial, Tianjin, Peoples' Republic of China
| | - Dong Li
- Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, Peoples' Republic of China
- Department of Neurology, Tianjin Children's Hospital (Tianjin University Children's Hospital), Tianjin, Peoples' Republic of China
| | - Chunquan Cai
- Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, Peoples' Republic of China
- Tianjin Pediatric Research Institute, Tianjin Children's Hospital (Tianjin University Children's Hospital), Tianjin, Peoples' Republic of China
- Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Children Hosptial, Tianjin, Peoples' Republic of China
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Chang YH, Kang EYC, Liu L, Jenny LA, Khang R, Seo GH, Lee H, Chen KJ, Wu WC, Hsiao MC, Wang NK. Maternal mosaicism in SSBP1 causing optic atrophy with retinal degeneration: implications for genetic counseling. Orphanet J Rare Dis 2023; 18:131. [PMID: 37259171 PMCID: PMC10233871 DOI: 10.1186/s13023-023-02748-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 05/18/2023] [Indexed: 06/02/2023] Open
Abstract
BACKGROUND Optic atrophy-13 with retinal and foveal abnormalities (OPA13) (MIM #165510) is a mitochondrial disease in which apparent bilateral optic atrophy is present and sometimes followed by retinal pigmentary changes or photoreceptors degeneration. OPA13 is caused by heterozygous mutation in the SSBP1 gene, associated with variable mitochondrial dysfunctions. RESULTS We have previously reported a 16-year-old Taiwanese male diagnosed with OPA13 and SSBP1 variant c.320G>A (p.Arg107Gln) was identified by whole exon sequence (WES). This variant was assumed to be de novo since his parents were clinically unaffected. However, WES and Sanger sequencing further revealed the proband's unaffected mother carrying the same SSBP1 variant with a 13% variant allele frequency (VAF) in her peripheral blood. That finding strongly indicates the maternal gonosomal mosaicism contributing to OPA13, which has not been reported before. CONCLUSIONS In summary, we described the first case of OPA13 caused by maternal gonosomal mosaicism in SSBP1. Parental mosaicism could be a serious issue in OPA13 diagnosis, and appropriate genetic counseling should be considered.
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Affiliation(s)
- Yin-Hsi Chang
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Eugene Yu-Chuan Kang
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Laura Liu
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Laura A Jenny
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, Columbia University, 635 West 165th Street, New York, NY, 10032, USA
| | - Rin Khang
- Division of Medical Genetics, 3Billion Inc., Seoul, South Korea
| | - Go Hun Seo
- Division of Medical Genetics, 3Billion Inc., Seoul, South Korea
| | - Hane Lee
- Division of Medical Genetics, 3Billion Inc., Seoul, South Korea
| | - Kuan-Jen Chen
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Wei-Chi Wu
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Meng-Chang Hsiao
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Nan-Kai Wang
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, Columbia University, 635 West 165th Street, New York, NY, 10032, USA.
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Chang YH, Kang EYC, Liu L, Jenny LA, Khang R, Seo GH, Lee H, Chen KJ, Wu WC, Hsiao MC, Wang NK. Maternal Mosaicism in SSBP1 Causing Optic Atrophy with Retinal Degeneration: Implications for Genetic Counseling. RESEARCH SQUARE 2023:rs.3.rs-2554402. [PMID: 36993412 PMCID: PMC10055506 DOI: 10.21203/rs.3.rs-2554402/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Background: Optic atrophy-13 with retinal and foveal abnormalities (OPA13) (MIM #165510) is a mitochondrial disease in which apparent bilateral optic atrophy is present and sometimes followed by retinal pigmentary changes or photoreceptors degeneration. OPA13 is caused by heterozygous mutation in the SSBP1 gene, associated with variable mitochondrial dysfunctions. Results: We have previously reported a 16-year-old Taiwanese male diagnosed with OPA13 and SSBP1 variant c.320G>A (p.Arg107Gln) was identified by whole exon sequence (WES). This variant was assumed to be de novo since his parents were clinically unaffected. However, WES and Sanger sequencing further revealed the proband’s unaffected mother carrying the same SSBP1 variant with a 13% variant allele frequency (VAF) in her peripheral blood. That finding strongly indicates the maternal gonosomal mosaicism contributing to OPA13, which has not been reported before. Conclusions: In summary, we described the first case of OPA13 caused by maternal gonosomal mosaicism in SSBP1 . Parental mosaicism could be a serious issue in OPA13 diagnosis, and appropriate genetic counseling should be considered.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Meng-Chang Hsiao
- Columbia University Medical Center: Columbia University Irving Medical Center
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Chen J, Chen Y, Yang Y, Niu X, Zhang J, Zeng Q, Liu A, Xu X, Yang X, Li S, Yang X, Wang Y, Zhang Y. Detecting genomic mosaicism in "de novo" genetic epilepsy by amplicon-based deep sequencing. J Hum Genet 2023; 68:73-80. [PMID: 36482122 DOI: 10.1038/s10038-022-01103-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 11/28/2022] [Accepted: 11/29/2022] [Indexed: 12/13/2022]
Abstract
AIM To investigate the occurrence of mosaicism in epilepsy probands and their parents using amplicon-based deep sequencing (ADS). METHODS Patients were recruited from the outpatient of Peking University First Hospital. Two hundred and sixty-four probands with pathogenic variants tested by next-generation sequencing (NGS) were enrolled. RESULTS Mosaic variants were detected in seventeen disease-associated genes from 20 probands, 5 paternal, and 6 maternal parents. The frequency of mosaicism was 11.74% (31/264). Mosaicism in 11 genes was identified from 20 probands with the mutant allelic fractions (MAFs) of 12.95-38.00% in autosomal dominant genes. Five paternal mosaicisms were identified in genes with a MAF of 6.30-20.99%, and six maternal mosaic individuals with a MAF of 2.07-21.90%. Only four mosaic parents had milder seizure history. The affected sibling had the same phenotype consistent with that of the proband, who inherited the variant of SLC1A2 or STXBP1 from their unaffected mosaic mothers, respectively. INTERPRETATION Mosaic phenomenon is not rare in families with epilepsy. Phenotypes of mosaic parents were milder or normal. Mosaicism detection is helpful to identify the mutation origin and it provides a theoretical basis for prenatal diagnosis of family reproduction. ADS is a reliable way of mosaicism detection for clinical application.
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Affiliation(s)
- Jiaoyang Chen
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, 100034, China
| | - Yi Chen
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, 100034, China
| | - Ying Yang
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, 100034, China
| | - Xueyang Niu
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, 100034, China
| | - Jing Zhang
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, 100034, China
| | - Qi Zeng
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, 100034, China
| | - Aijie Liu
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, 100034, China
| | - Xiaojing Xu
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, 100034, China
| | - Xiaoxu Yang
- Center for Bioinformatics, Peking University, Beijing, 100871, China
| | - Shupin Li
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, 100034, China
| | - Xiaoling Yang
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, 100034, China
| | - Yi Wang
- Department of Neurology, National Epilepsy Center, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, 201102, China
| | - Yuehua Zhang
- Department of Pediatrics and Pediatric Epilepsy Center, Peking University First Hospital, Beijing, 100034, China.
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Chen Y, Yang X, Chen J, Yang X, Yang Y, Liu A, Zhang X, Wu W, Sun D, Yang Z, Jiang Y, Zhang Y. PCDH19-related epilepsy in mosaic males: The phenotypic implication of genotype and variant allele frequency. Front Neurol 2022; 13:1041509. [PMID: 36408521 PMCID: PMC9669318 DOI: 10.3389/fneur.2022.1041509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Accepted: 10/06/2022] [Indexed: 11/15/2023] Open
Abstract
OBJECTIVE To analyze the genotypes and phenotypes of mosaic male patients with PCDH19-related epilepsy (PCDH19-RE) and explore the correlation between genotype, variant allele frequency (VAF), and phenotypic severity. METHODS Clinical data and peripheral blood samples of 11 male mosaic patients were collected and analyzed in our study. The VAF of the PCDH19 gene from peripheral blood was quantified using amplicon-based deep sequencing. Additional 20 mosaic male patients with PCDH19-RE were collected from the published literature, with 10 patients whose VAFs of the PCDH19 gene were available for analytic purposes. RESULTS In our cohort of 11 patients, 10 variants were identified, and four were novel. The VAF of the PCDH19 gene from peripheral blood ranged from 27 to 90%. The median seizure onset age was 6 months (range: 4-9 months). Clinical manifestations included cluster seizures (100%), fever sensitivity (73%), focal seizures (91%), developmental delay/intellectual disability (DD/ID, 82%), and autistic features (45%). Thirty-one mosaic male patients collected from our cohort and the literature developed seizures mostly (87%) within one year of age. Variant types included missense variants (42%), truncating variants (52%), splice variants (3%), and whole PCDH19 deletion (3%). Among 21 patients with a definite VAF from our cohort and the literature, nine had a low VAF ( ≤ 50%) and 12 had a high VAF (> 50%). Seventy-five percent of variants from the high VAF group were missense, whereas 89% of those from the low VAF group were truncations. The median seizure onset age was 6 months in the low VAF group and 9 months in the high VAF group (p = 0.018). Forty-four percent (4/9) of patients from the low VAF group achieved seizure-free for ≥1 year, whereas none of the 12 patients from the high VAF group did (p = 0.021). DD/ID was present in 83% (10/12) of the high VAF group and 56% (5/9) of the low VAF group (p = 0.331). CONCLUSION The predominant variant types were truncating and missense variants. Missense variants tended to have higher VAFs. Patients with a high VAF were more likely to have a more severe epileptic phenotype. Our findings shed light on the phenotypic implications of VAF in mosaic males with PCDH19-RE.
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Affiliation(s)
- Yi Chen
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xiaoxu Yang
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Jiaoyang Chen
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xiaoling Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Ying Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Aijie Liu
- Department of Pediatric Neurology, Capital Institute of Pediatrics, Beijing, China
| | - Xiaoli Zhang
- Department of Pediatrics, The Third Affiliated Hospital of Zheng Zhou University, Zhengzhou, China
| | - Wenjuan Wu
- Department of Neurology, Hebei Children's Hospital, Shijiazhuang, China
| | - Dan Sun
- Department of Neurology, Wuhan Children's Hospital, Wuhan, China
| | - Zhixian Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yuwu Jiang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yuehua Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
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11
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Chen G, Zhou H, Lu Y, Wang Y, Li Y, Xue J, Cheng K, Huang R, Han J. Case report: A novel mosaic nonsense mutation of PCDH19 in a Chinese male with febrile epilepsy. Front Neurol 2022; 13:992781. [PMID: 36247776 PMCID: PMC9556843 DOI: 10.3389/fneur.2022.992781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 09/12/2022] [Indexed: 11/13/2022] Open
Abstract
The clinical features of the PCDH19 gene mutation include febrile epilepsy ranging from mild to severe, with or without intellectual disability, cognitive impairment, and psych-behavioral disorders, but there has been little research on males with the mosaic mutation of PCDH19. This study reported a novel, de novo, and mosaic PCDH19 nonsense mutation (NM_001184880: c.840C > A, p. Tyr280*) from a Chinese male in early middle childhood by trio whole-exome sequence (Trio-WES) and confirmed by Sanger sequence. The proportion of the mosaic mutation (c.840C > A, p. Tyr280*) in PCDH19 was 27.9% in, buccal mucosal cells, 48.3% in exfoliated cells in the urine, and 50.6% in peripheral blood of proband. He had the first onset of seizures in toddlerhood with febrile epilepsy, mild impaired cognitive psychological, and behavioral abnormalities. The electroencephalography (EEG) exhibited sharp waves and sharp slow complex waves in the bilateral parietal, occipital, and posterior temporal regions during the interictal period. Pinpoint white matter lesions in the periventricular white matter and slightly bulging bilateral ventricles appeared on cranial magnetic resonance imaging (MRI). With Depakine and Keppra he gained good control over his epilepsy. This study might expand the genotypes and broaden the spectrums.
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Affiliation(s)
- Guilan Chen
- Department of Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Hang Zhou
- Department of Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Yan Lu
- Department of Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - You Wang
- Department of Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
- The First Clinical Medical College, Southern Medical University, Guangzhou, China
| | - Yingsi Li
- Department of Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Jiaxin Xue
- Department of Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Ken Cheng
- Department of Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
- School of Medicine, South China University of Technology, Guangzhou, China
| | - Ruibin Huang
- Department of Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Jin Han
- Department of Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
- *Correspondence: Jin Han
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12
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Deng H, Zhang Y, Ding J, Wang F. Detection of Very Low-Level Somatic Mosaic COL4A5 Splicing Variant in Asymptomatic Female Using Droplet Digital PCR. Front Med (Lausanne) 2022; 9:847056. [PMID: 35360741 PMCID: PMC8963732 DOI: 10.3389/fmed.2022.847056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Accepted: 02/09/2022] [Indexed: 12/02/2022] Open
Abstract
Background Alport syndrome is a hereditary glomerulopathy featured by haematuria, proteinuria, and progressive renal failure. X-linked Alport syndrome (XLAS) due to COL4A5 disease-causing variants is the most common form. In the case of XLAS resulting from 10–18% presumed de novo COL4A5 disease-causing variants, there are only a few studies for mosaicism in the probands or parents. Very low-level (<1.0%) somatic mosaicism for COL4A5 disease-causing variants has not been published. Materials and Methods Chinese XLAS families with suspected parental mosaicism were enrolled in the present study to evaluate the forms of mosaicism, to offer more appropriate genetic counseling. PCR and direct sequencing were used to detect COL4A5 disease-causing variants harbored by the affected probands in parental multi-tissue DNAs (peripheral blood, urine sediments, saliva, hair), and droplet digital PCR (ddPCR) was used to quantify the mutant COL4A5 allelic fractions in parental different samples such as peripheral blood, saliva, and urine sediments. Results A Chinese asymptomatic female with suspected somatic and germline mosaicism was enrolled in the present study. She gave birth to two boys with XLAS caused by a hemizygous disease-causing variant c. 2245-1G>A in COL4A5 (NM_033380) intron 28, whereas this disease-causing variant was not detected in genomic DNA extracted from peripheral blood leukocytes in the woman using Sanger sequencing. She had multiple normal urine test results, and continuous linear immunofluorescence staining of α2 (IV) and α5 (IV) chains of skin tissue. Sanger sequencing demonstrated that COL4A5 disease-causing variant c. 2245-1G>A was not detected in her genomic DNAs isolated from urine sediments, saliva, and hair roots. Using ddPCR, the wild-type and mutant-type (c.2245-1G>A) COL4A5 was identified in the female's genomic DNAs isolated from peripheral blood, saliva, and urine sediments. The mutant allelic fractions in these tissues were 0.26% (peripheral blood), 0.73% (saliva), and 1.39% (urine), respectively. Conclusions Germline and very low-level somatic mosaicism for a COL4A5 splicing variant was detected in an asymptomatic female, which highlights that parental mosaicism should be excluded when a COL4A5 presumed de novo disease-causing variant is detected.
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Salinas V, Martínez N, Maturo JP, Rodriguez-Quiroga SA, Zavala L, Medina N, Amartino H, Sfaello I, Agosta G, Serafín EM, Morón DG, Kauffman MA, Vega P. Clinical next generation sequencing in developmental and epileptic encephalopathies: Diagnostic relevance of data re-analysis and variants re-interpretation. Eur J Med Genet 2021; 64:104363. [PMID: 34673242 DOI: 10.1016/j.ejmg.2021.104363] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 09/24/2021] [Accepted: 10/08/2021] [Indexed: 11/26/2022]
Abstract
Developmental and epileptic encephalopathies (DEE) are complex pediatric epilepsies, in which heterogeneous pathogenic factors play an important role. Next-generation-sequencing based tools have shown excellent effectiveness. The constant increase in the number of new genotype-phenotype associations suggests the periodic need for re-interpretation and re-analysis of genetic studies without positive results. In this study, we report the diagnostic utility of targeted gene panel sequencing and whole exome sequencing in 55 Argentine subjects with DEE, focusing on the utility of re-interpretation and re-analysis of undetermined and negative genetic diagnoses. The new information in biomedical literature and databases was used for the re-interpretation. For re-analysis, sequencing data processing was repeated using updated bioinformatics tools. Initially, pathogenic variants were detected in 21 subjects (38%). After an average time of 29 months, 25% of the subjects without a genetic diagnosis were re-categorized as diagnosed. Finally, the overall diagnostic yield increased to 53% (29 subjects). In consequence of the re-interpretation and re-analysis, we identified novel variants in the genes: CHD2, COL4A1, FOXG1, GABRA1, GRIN2B, HNRNPU, KCNQ2, MECP2, PCDH19, SCN1A, SCN2A, SCN8A, SLC6A1, STXBP1 and WWOX. Our results expand the diagnostic yield of this subgroup of infantile and childhood seizures and demonstrate the importance of re-evaluation of genetic tests in subjects without an identified causative etiology.
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Affiliation(s)
- Valeria Salinas
- Neurogenetics Unit, Hospital JM Ramos Mejía, Buenos Aires, Argentina; Precision Medicine and Clinical Genomics Group, Translational Medicine Research Institute-CONICET, Faculty of Biomedical Sciences, Universidad Austral, Buenos Aires, Argentina.
| | - Nerina Martínez
- Neurogenetics Unit, Hospital JM Ramos Mejía, Buenos Aires, Argentina.
| | - Josefina Pérez Maturo
- Neurogenetics Unit, Hospital JM Ramos Mejía, Buenos Aires, Argentina; Precision Medicine and Clinical Genomics Group, Translational Medicine Research Institute-CONICET, Faculty of Biomedical Sciences, Universidad Austral, Buenos Aires, Argentina.
| | | | - Lucia Zavala
- Neurogenetics Unit, Hospital JM Ramos Mejía, Buenos Aires, Argentina.
| | - Nancy Medina
- Neurogenetics Unit, Hospital JM Ramos Mejía, Buenos Aires, Argentina.
| | - Hernán Amartino
- Paediatric Neurology Unit, Hospital Universitario Austral, Buenos Aires, Argentina.
| | - Ignacio Sfaello
- CETES, Instituto de Neurología Infanto-Juvenil, Córdoba, Argentina.
| | - Guillermo Agosta
- Paediatric Neurology Unit, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina.
| | | | | | - Marcelo A Kauffman
- Neurogenetics Unit, Hospital JM Ramos Mejía, Buenos Aires, Argentina; Precision Medicine and Clinical Genomics Group, Translational Medicine Research Institute-CONICET, Faculty of Biomedical Sciences, Universidad Austral, Buenos Aires, Argentina.
| | - Patricia Vega
- Neurogenetics Unit, Hospital JM Ramos Mejía, Buenos Aires, Argentina.
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14
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Breuss MW, Yang X, Gleeson JG. Sperm mosaicism: implications for genomic diversity and disease. Trends Genet 2021; 37:890-902. [PMID: 34158173 PMCID: PMC9484299 DOI: 10.1016/j.tig.2021.05.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/26/2021] [Accepted: 05/27/2021] [Indexed: 12/18/2022]
Abstract
While sperm mosaicism has few consequences for men, the offspring and future generations are unwitting recipients of gonadal cell mutations, often yielding severe disease. Recent studies, fueled by emergent technologies, show that sperm mosaicism is a common source of de novo mutations (DNMs) that underlie severe pediatric disease as well as human genetic diversity. Sperm mosaicism can be divided into three types: Type I arises during sperm meiosis and is non-age dependent; Type II arises in spermatogonia and increases as men age; and Type III arises during paternal embryogenesis, spreads throughout the body, and contributes stably to sperm throughout life. Where Types I and II confer little risk of recurrence, Type III may confer identifiable risk to future offspring. These mutations are likely to be the single largest contributor to human genetic diversity. New sequencing approaches may leverage this framework to evaluate and reduce disease risk for future generations.
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Affiliation(s)
- Martin W Breuss
- Department of Pediatrics, Section of Genetics and Metabolism, University of Colorado School of Medicine, Aurora, CO, USA
| | - Xiaoxu Yang
- Rady Children's Institute for Genomic Medicine, Department of Neurosciences, University of California, San Diego, CA, USA
| | - Joseph G Gleeson
- Rady Children's Institute for Genomic Medicine, Department of Neurosciences, University of California, San Diego, CA, USA.
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15
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Yang X, Breuss MW, Xu X, Antaki D, James KN, Stanley V, Ball LL, George RD, Wirth SA, Cao B, Nguyen A, McEvoy-Venneri J, Chai G, Nahas S, Van Der Kraan L, Ding Y, Sebat J, Gleeson JG. Developmental and temporal characteristics of clonal sperm mosaicism. Cell 2021; 184:4772-4783.e15. [PMID: 34388390 PMCID: PMC8496133 DOI: 10.1016/j.cell.2021.07.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/12/2021] [Accepted: 07/14/2021] [Indexed: 01/07/2023]
Abstract
Throughout development and aging, human cells accumulate mutations resulting in genomic mosaicism and genetic diversity at the cellular level. Mosaic mutations present in the gonads can affect both the individual and the offspring and subsequent generations. Here, we explore patterns and temporal stability of clonal mosaic mutations in male gonads by sequencing ejaculated sperm. Through 300× whole-genome sequencing of blood and sperm from healthy men, we find each ejaculate carries on average 33.3 ± 12.1 (mean ± SD) clonal mosaic variants, nearly all of which are detected in serial sampling, with the majority absent from sampled somal tissues. Their temporal stability and mutational signature suggest origins during embryonic development from a largely immutable stem cell niche. Clonal mosaicism likely contributes a transmissible, predicted pathogenic exonic variant for 1 in 15 men, representing a life-long threat of transmission for these individuals and a significant burden on human population health.
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Affiliation(s)
- Xiaoxu Yang
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA; Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Martin W Breuss
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA; Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Xin Xu
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA; Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Danny Antaki
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA; Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Kiely N James
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA; Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Valentina Stanley
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA; Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Laurel L Ball
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA; Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Renee D George
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA; Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Sara A Wirth
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA; Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Beibei Cao
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA; Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - An Nguyen
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA; Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Jennifer McEvoy-Venneri
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA; Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Guoliang Chai
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA; Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Shareef Nahas
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | | | - Yan Ding
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Jonathan Sebat
- Beyster Center for Genomics of Psychiatric Diseases, University of California, San Diego, La Jolla, CA 92093, USA; Department of Psychiatry, University of California, San Diego, La Jolla, CA 92093, USA; Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Joseph G Gleeson
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA; Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA.
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16
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X-chromosome inactivation and PCDH19-associated epileptic encephalopathy: A novel PCDH19 variant in a Chinese family. Clin Chim Acta 2021; 521:285-288. [PMID: 34331950 DOI: 10.1016/j.cca.2021.07.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 07/26/2021] [Accepted: 07/26/2021] [Indexed: 11/23/2022]
Abstract
BACKGROUND Developmental and epileptic encephalopathy 9 (DEE9, MIM #300088) is an early onset seizure disorder associated with cognitive impairment and behavioral disturbances. It is caused by mutation in protocadherin 19 with an unusual X-linked inheritance selectively involving heterozygous females or mosaic hemizygous males, while hemizygous males are unaffected. Cellular interference was the postulated mechanism underlying the unusual inheritance pattern. CASE REPORT We report a Chinese girl who presented with severe treatment refractory seizures at 26 months of age and was found heterozygous for a novel likely pathogenic missense variant NM_001184880.2:c.488T>A p.(Val163Glu) in PCDH19. Her younger sister, who was also heterozygous for the variant, was asymptomatic with normal development at the time of reporting at 37 months of age. X-chromosome inactivation study by androgen receptor gene methylation assay in DNA from peripheral leukocytes was performed which demonstrated somewhat skewed X-chromosome inactivation in the proband and extremely skewed X-chromosome inactivation in the asymptomatic younger sibling. CONCLUSION PCDH19-related seizure disorder has incomplete penetrance and variable expressivity. Further studies are required to determine the potential role of X-chromosome inactivation on the phenotypic variability and patient outcomes. Liberal referral for PCDH19 testing among female patients with early-onset seizures should be considered to enhance case detection.
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Mazzurco M, Pulvirenti G, Caccamo M, Presti S, Soma R, Salafia S, Praticò ER, Filosco F, Falsaperla R, Praticò AD. PCDH19-Related Epilepsies. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0041-1728641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractProtocadherin-19 (PCDH19) is considered one of the most relevant genes related to epilepsy. To date, more than 150 mutations have been identified as causative for PCDH19-female epilepsy (also known as early infantile epileptic encephalopathy-9, EIEE9), which is characterized by early onset epilepsy, intellectual disabilities, and behavioral disturbances. More recently, mosaic-males (i.e., exhibiting the variants in less than 25% of their cells) have been described as affected by infant-onset epilepsy associated with intellectual disability, as well as compulsive or aggressive behavior and autistic features. Although little is known about the physiological role of PCDH19 protein and the pathogenic mechanisms that lead to EIEE9, many reports and clinical observation seem to suggest a relevant role of this protein in the development of cellular hyperexcitability. However, a genotype–phenotype correlation is difficult to establish. The main feature of EIEE9 consists in early onset of seizures, which generally occur in clusters lasting 1 to 5 minutes and repeating up to 10 times a day for several days. Seizures tend to present during febrile episodes, similarly to the first phases of Dravet syndrome and PCDH19 variants have been found in ∼25% of females who present with features of Dravet syndrome and testing negative for SCN1A variants. There is no “standardized” treatment for PCDH19-related epilepsy and most of the patients receiving a combination of several drugs. In this review, we focus on the latest researches on these aspects, with regard to protein expression, its known functions, and the mechanisms by which the protein acts. The clinical phenotypes related to PCDH19 mutations are also discussed.
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Affiliation(s)
| | - Giulio Pulvirenti
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Martina Caccamo
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Santiago Presti
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Rachele Soma
- Unit of Rare Diseases of the Nervous System in Childhood, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
| | | | | | - Federica Filosco
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Raffaele Falsaperla
- Unit of Pediatrics and Pediatric Emergency, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
- Unit of Neonatal Intensive Care and Neonatology, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
| | - Andrea D. Praticò
- Unit of Rare Diseases of the Nervous System in Childhood, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
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18
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Lin S, He Z, Huang L, Liu J, Lei T, Wu J, Huang P, Zhou Y, Luo Y. Case Report: Low-Level Maternal Mosaicism of a Novel CREBBP Variant Causes Recurrent Rubinstein-Taybi Syndrome in Two Siblings of a Chinese Family. Front Genet 2021; 12:640992. [PMID: 33747050 PMCID: PMC7970026 DOI: 10.3389/fgene.2021.640992] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 02/15/2021] [Indexed: 01/05/2023] Open
Abstract
Familial Rubinstein-Taybi syndrome (RSTS) with recurrent RSTS siblings and apparently unaffected parents is rare; such cases might result from parental somatic and/or germline mosaicism. Parental low-level (<10%) germline mosaicism in the CREBBP-associated RSTS family has not been reported. Here, we present our studies of a Chinese family with two RSTS siblings and apparently unaffected parents. We detected the apparent de novo variant (DNV) c.3235C>T (p.Gln1079*) in CREBBP in the siblings via trio whole-exome sequencing. High-depth next-generation sequencing (NGS) for the parents revealed a low-level (<10%) mosaic variant in both the peripheral blood (3.64%) and buccal mucosa (1.94%) of the unaffected mother, indicating maternal somatic and germline mosaicism. Peripheral blood RNA-sequencing analysis for the patients and normal individuals indicated that the c.3235C>T (p.Gln1079*) non-sense variant did not trigger nonsense-mediated mRNA decay to reduce CREBBP mRNA levels. Transcriptome analysis revealed 151 downregulated mRNAs and 132 upregulated mRNAs between the patients and normal individuals. This study emphasizes that high-depth NGS using multiple specimens might be applied for a family with an affected sibling caused by an apparent CREBBP DNV to identify potential low-level parental mosaicism and provide an assessment of recurrence risk.
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Affiliation(s)
- Shaobin Lin
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Zhiming He
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Linhuan Huang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Jialiu Liu
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Ting Lei
- Department of Ultrasonic Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Jianzhu Wu
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Peizhi Huang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Yi Zhou
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Yanmin Luo
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
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Togi S, Ura H, Niida Y. Optimization and Validation of Multimodular, Long-Range PCR-Based Next-Generation Sequencing Assays for Comprehensive Detection of Mutation in Tuberous Sclerosis Complex. J Mol Diagn 2021; 23:424-446. [PMID: 33486073 DOI: 10.1016/j.jmoldx.2020.12.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 10/01/2020] [Accepted: 12/16/2020] [Indexed: 12/17/2022] Open
Abstract
The genetic diagnosis of tuberous sclerosis complex is difficult because of its broad spectrum of mutations. In addition to point mutations in coding regions, intragenic or chromosomal-level large deletions, deep intronic splicing mutations, and mosaic mutations represent a significant proportion of the mutations. In this study, multimodular, long-range PCR-based next-generation sequencing assays were optimized and validated using >100 samples with known TSC1 and TSC2 variants. Multiplex, long-range PCR covering the entire genomic region of both genes detected all 138 known variants; however, it also yielded false-positive results. Intragenic large deletions were detected with accurate breakpoint sequences. Chromosomal-level deletions were estimated by discordant allele segregation in the family and confirmed by DNA microarray. Deep intronic mutations were verified using a combination of long-range DNA PCR and full-length mRNA sequencing. DNA samples were mixed to simulate mosaic mutations, and most variants were detected but could not be distinguished from equivalently detected false-positive results. Repeated false-positive results were classified, and the strategy of selecting the common variants detected in the duplicate analysis and eliminating known false-positive results improved the sensitivity (85.2%) and positive predictive value (96.6%) of a 10% mosaic simulation. Long-range PCRbased next-generation sequencing is a highly versatile genetic test; however, confirmation tests remain necessary for clinical use because false-positive results cannot be completely eliminated from single experiments.
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Affiliation(s)
- Sumihito Togi
- Center for Clinical Genomics, Kanazawa Medical University, Uchinada, Japan
| | - Hiroki Ura
- Center for Clinical Genomics, Kanazawa Medical University, Uchinada, Japan
| | - Yo Niida
- Division of Genomic Medicine, Department of Advanced Medicine, Medical Research Institute, Kanazawa Medical University, Uchinada, Japan.
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20
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Lin L, Zhang Y, Pan H, Wang J, Qi Y, Ma Y. Clinical and genetic characteristics and prenatal diagnosis of patients presented GDD/ID with rare monogenic causes. Orphanet J Rare Dis 2020; 15:317. [PMID: 33176815 PMCID: PMC7656751 DOI: 10.1186/s13023-020-01599-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 10/26/2020] [Indexed: 12/18/2022] Open
Abstract
Background Global developmental delay/intellectual disability (GDD/ID), used to be named as mental retardation (MR), is one of the most common phenotypes in neurogenetic diseases. In this study, we described the diagnostic courses, clinical and genetic characteristics and prenatal diagnosis of a cohort with patients presented GDD/ID with monogenic causes, from the perspective of a tertiary genetic counseling and prenatal diagnostic center. Method We retrospectively analyzed the diagnostic courses, clinical characteristics, and genetic spectrum of patients presented GDD/ID with rare monogenic causes. We also conducted a follow-up study on prenatal diagnosis in these families. Pathogenicity of variants was interpreted by molecular geneticists and clinicians according to the guidelines of the American College of Medical Genetics and Genomics (ACMG). Results Among 81 patients with GDD/ID caused by rare monogenic variants it often took 0.5–4.5 years and 2–8 referrals to obtain genetic diagnoses. Devlopmental delay typically occurred before 3 years of age, and patients usually presented severe to profound GDD/ID. The most common co-existing conditions were epilepsy (58%), microcephaly (21%) and facial anomalies (17%). In total, 111 pathogenic variants were found in 62 different genes among the 81 pedigrees, and 56 variants were novel. The most common inheritance patterns in this outbred Chinese population were autosomal dominant (AD; 47%), following autosomal recessive (AR; 37%), and X-linked (XL; 16%). SCN2A, SHANK3 and STXBP1 were important causal genes. Hot-spot variants were rarely found. By the follow-up, 33 affected families, including 15, 13 and 5 families inherited in AR, AD and XL modes respectively, had undergone prenatal diagnosis. And the recurrence rates are 26.7%, 15.4% and 20% for families inherited in AR, AD, and XL patterns. Conclusion Patients presented with GDD/ID caused by rare single gene variants are characterized by early onset, relatively severe symptoms and great clinical variability and genetic heterogeneity. Timely referrals to genetic counseling and prenatal diagnostic laboratories are important for affected families planning to have additional children.
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Affiliation(s)
- Liling Lin
- Department of Central Laboratory, Peking University First Hospital, No. 8, Xishiku Street, Xicheng District, Beijing, 100034, China
| | - Ying Zhang
- Department of Central Laboratory, Peking University First Hospital, No. 8, Xishiku Street, Xicheng District, Beijing, 100034, China
| | - Hong Pan
- Department of Central Laboratory, Peking University First Hospital, No. 8, Xishiku Street, Xicheng District, Beijing, 100034, China
| | - Jingmin Wang
- Department of Pediatrics, Peking University First Hospital, No. 8, Xishiku Street, Xicheng District, Beijing, 100034, China
| | - Yu Qi
- Department of Central Laboratory, Peking University First Hospital, No. 8, Xishiku Street, Xicheng District, Beijing, 100034, China
| | - Yinan Ma
- Department of Central Laboratory, Peking University First Hospital, No. 8, Xishiku Street, Xicheng District, Beijing, 100034, China.
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21
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Kozina AA, Okuneva EG, Baryshnikova NV, Fedonyuk ID, Kholin AA, Il'ina ES, Krasnenko AY, Stetsenko IF, Plotnikov NA, Klimchuk OI, Surkova EI, Ilinsky VV. Two novel PCDH19 mutations in Russian patients with epilepsy with intellectual disability limited to females: a case report. BMC MEDICAL GENETICS 2020; 21:209. [PMID: 33087045 PMCID: PMC7579871 DOI: 10.1186/s12881-020-01119-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 09/03/2020] [Indexed: 11/16/2022]
Abstract
Background Epilepsy with intellectual disability limited to females (Epileptic encephalopathy, early infantile, 9; EIEE9) is a rare early infantile epileptic encephalopathy characterized by an unusual X-linked inheritance: females with heterozygous mutations are affected, while hemizygous males are not. Case presentation We describe the clinical and molecular characteristics of 2 Russian patients with EIEE9 (females, ages 3 years and 7 years). In these patients seizures developed at the age of 3 years. Additionally, for our patients and for cases described in the literature we searched for a possible relationship between the type and localization of the mutation and the EIEE9 clinical phenotype. Conclusions We identified two novel PCDH19 mutations in EIEE9 patients: a missense mutation in exon 1 (c.1236C > A, p.Asp412Glu) and a frameshift in exon 3 (c.2386_2387insGTCT, p.Thr796fs). We conclude that the age of seizure onset and the presence of intellectual disability may depend not on the type and localization of PCDH19 mutations, but on the X-inactivation status. The study also highlights the need to screen for EIEE9 among young female epilepsy patients.
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Affiliation(s)
- Anastasiya Aleksandrovna Kozina
- Institute of Biomedical Chemistry, Pogodinskaya street 10/8, 119121, Moscow, Russia.,Pirogov Russian National Research Medical University, Ostrovitianova street 1, 117997, Moscow, Russia
| | | | - Natalia Vladimirovna Baryshnikova
- Pirogov Russian National Research Medical University, Ostrovitianova street 1, 117997, Moscow, Russia.,Genotek Ltd., Nastavnicheskii pereulok 17/1, 105120, Moscow, Russia
| | - Inessa Dmitrievna Fedonyuk
- Russian Children's Clinical Hospital of Pirogov Russian National Research Medical University, Leniskiy prospekt 117, 117513, Moscow, Russia
| | - Alexey Aleksandrovich Kholin
- Pirogov Russian National Research Medical University, Ostrovitianova street 1, 117997, Moscow, Russia.,Russian Children's Clinical Hospital of Pirogov Russian National Research Medical University, Leniskiy prospekt 117, 117513, Moscow, Russia
| | - Elena Stepanovna Il'ina
- Russian Children's Clinical Hospital of Pirogov Russian National Research Medical University, Leniskiy prospekt 117, 117513, Moscow, Russia
| | | | | | | | | | | | - Valery Vladimirovich Ilinsky
- Institute of Biomedical Chemistry, Pogodinskaya street 10/8, 119121, Moscow, Russia.,Pirogov Russian National Research Medical University, Ostrovitianova street 1, 117997, Moscow, Russia.,Genotek Ltd., Nastavnicheskii pereulok 17/1, 105120, Moscow, Russia.,Vavilov Institute of General Genetics, Gubkina street 3, 119333, Moscow, Russia
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22
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Rakotomamonjy J, Sabetfakhri NP, McDermott SL, Guemez-Gamboa A. Characterization of seizure susceptibility in Pcdh19 mice. Epilepsia 2020; 61:2313-2320. [PMID: 32944953 DOI: 10.1111/epi.16675] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 07/22/2020] [Accepted: 08/10/2020] [Indexed: 02/02/2023]
Abstract
OBJECTIVE PCDH19-related epilepsy is characterized by a distinctive pattern of X-linked inheritance, where heterozygous females exhibit seizures and hemizygous males are asymptomatic. A cellular interference mechanism resulting from the presence of both wild-type and mutant PCDH19 neurons in heterozygous patients or mosaic carriers of PCDH19 variants has been hypothesized. We aim to investigate seizure susceptibility and progression in the Pchd19 mouse model. METHODS We assessed seizure susceptibility and progression in the Pcdh19 mouse model using three acute seizure induction paradigms. We first induced focal, clonic seizures using the 6-Hz psychomotor test. Mice were stimulated with increasing current intensities and graded according to a modified Racine scale. We next induced generalized seizures using flurothyl or pentylenetetrazol (PTZ), both γ-aminobutyric acid type A receptor function inhibitors, and recorded latencies to myoclonic and generalized tonic-clonic seizures. RESULTS Pcdh19 knockout and heterozygous females displayed increased seizure susceptibility across all current intensities in the 6-Hz psychomotor test, and increased severity overall. They also exhibited shorter latencies to generalized seizures following flurothyl, but not PTZ, seizure induction. Hemizygous males showed comparable seizure incidence and severity to their wild-type male littermates across all paradigms tested. SIGNIFICANCE The heightened susceptibility observed in Pcdh19 knockout females suggests additional mechanisms other than cellular interference are at play in PCDH19-related epilepsy. Further experiments are needed to understand the variability in seizure susceptibility so that this model can be best utilized toward development of future therapeutic strategies for PCDH19-related epilepsy.
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Affiliation(s)
- Jennifer Rakotomamonjy
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Niki P Sabetfakhri
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Sean L McDermott
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Alicia Guemez-Gamboa
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
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23
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Gong P, Jiao X, Zhang Y, Yang Z. Complex Mosaicism of Two Distinct Mutations in a Female Patient With KCNA2-Related Encephalopathy: A Case Report. Front Genet 2020; 11:911. [PMID: 32903602 PMCID: PMC7438874 DOI: 10.3389/fgene.2020.00911] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 07/22/2020] [Indexed: 12/29/2022] Open
Abstract
KCNA2 gene mutations were described to cause a new molecular entity within the developmental and epileptic or epileptic encephalopathies. Here, we firstly reported a patient with an unusual mosaicism for KCNA2, presenting two distinct mosaic missense mutations at the same loci. Clinical trio-based whole-exome sequencing using next-generation sequencing (NGS) revealed two novel mutations in KCNA2: c.1225A > T [p.(Ile409Phe)] and c.1225A > C [p.(Ile409Leu)]. Both missense mutations were in mosaic status and Sanger sequencing confirmed them as de novo. The affected 5-year-old girl presented as seizures with fever sensitivity, and mild cognitive and behavioral disorders. EEG showed focal centrotemporal epileptiform discharges accompanied by nocturnal focal seizures at the age of slightly older than 5 years, more likely carrying a loss-of-function mutation of KCNA2-related phenotype. Further NGS with a mean coverage of 6950 × showed 26% (mosaic mutation reads/total reads) of the c.1225A > T mutation and 23% of the c.1225A > C mutation. The sum of their allele fractions was close to 50%, approximately equal to a heterozygous variant. The patient had no seizures for 8 months on combination of levetiracetam (18.75 mg/kg/d) and valproate (20 mg/kg/d) till the last follow-up at the age of 5 years and 11 months. Our findings highlighted the two mosaic mutations responsible for the pathogenesis of KCNA2-related encephalopathy. The patient expanded the mutational spectrum of KCNA2-related encephalopathy and provided new insight into the complex genetic disorder.
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Affiliation(s)
- Pan Gong
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xianru Jiao
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yuehua Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Zhixian Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
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24
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Henke C, Töllner K, van Dijk RM, Miljanovic N, Cordes T, Twele F, Bröer S, Ziesak V, Rohde M, Hauck SM, Vogel C, Welzel L, Schumann T, Willmes DM, Kurzbach A, El-Agroudy NN, Bornstein SR, Schneider SA, Jordan J, Potschka H, Metallo CM, Köhling R, Birkenfeld AL, Löscher W. Disruption of the sodium-dependent citrate transporter SLC13A5 in mice causes alterations in brain citrate levels and neuronal network excitability in the hippocampus. Neurobiol Dis 2020; 143:105018. [PMID: 32682952 DOI: 10.1016/j.nbd.2020.105018] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 07/08/2020] [Accepted: 07/11/2020] [Indexed: 12/28/2022] Open
Abstract
In addition to tissues such as liver, the plasma membrane sodium-dependent citrate transporter, NaCT (SLC13A5), is highly expressed in brain neurons, but its function is not understood. Loss-of-function mutations in the human SLC13A5 gene have been associated with severe neonatal encephalopathy and pharmacoresistant seizures. The molecular mechanisms of these neurological alterations are not clear. We performed a detailed examination of a Slc13a5 deletion mouse model including video-EEG monitoring, behavioral tests, and electrophysiologic, proteomic, and metabolomic analyses of brain and cerebrospinal fluid. The experiments revealed an increased propensity for epileptic seizures, proepileptogenic neuronal excitability changes in the hippocampus, and significant citrate alterations in the CSF and brain tissue of Slc13a5 deficient mice, which may underlie the neurological abnormalities. These data demonstrate that SLC13A5 is involved in brain citrate regulation and suggest that abnormalities in this regulation can induce seizures. The present study is the first to (i) establish the Slc13a5-knockout mouse model as a helpful tool to study the neuronal functions of NaCT and characterize the molecular mechanisms by which functional deficiency of this citrate transporter causes epilepsy and impairs neuronal function; (ii) evaluate all hypotheses that have previously been suggested on theoretical grounds to explain the neurological phenotype of SLC13A5 mutations; and (iii) indicate that alterations in brain citrate levels result in neuronal network excitability and increased seizure propensity.
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Affiliation(s)
- Christine Henke
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine, Technische Universität Dresden, Germany; Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Kathrin Töllner
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - R Maarten van Dijk
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University, Munich, Germany
| | - Nina Miljanovic
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University, Munich, Germany
| | - Thekla Cordes
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Friederike Twele
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Sonja Bröer
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Vanessa Ziesak
- Oscar-Langendorff-Institute of Physiology, Rostock University Medical Center, Rostock, Germany
| | - Marco Rohde
- Oscar-Langendorff-Institute of Physiology, Rostock University Medical Center, Rostock, Germany
| | - Stefanie M Hauck
- Research Unit Protein Science, Helmholtz Center Munich, Neuherberg, Germany
| | - Charlotte Vogel
- Department of Biometry, Epidemiology and Information Processing, University of Veterinary Medicine Hannover, Germany
| | - Lisa Welzel
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; Center for Systems Neuroscience, 30559 Hannover, Germany
| | - Tina Schumann
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine, Technische Universität Dresden, Germany; Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Diana M Willmes
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine, Technische Universität Dresden, Germany; Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Anica Kurzbach
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine, Technische Universität Dresden, Germany; Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Nermeen N El-Agroudy
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine, Technische Universität Dresden, Germany; Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Stefan R Bornstein
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine, Technische Universität Dresden, Germany
| | | | - Jens Jordan
- Institute for Aerospace Medicine, German Aerospace Center (DLR) and Chair for Aerospace Medicine, University of Cologne, Cologne, Germany
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University, Munich, Germany
| | - Christian M Metallo
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA; Moores Cancer Center, University of California, San Diego, La Jolla, CA 92037, USA
| | - Rüdiger Köhling
- Oscar-Langendorff-Institute of Physiology, Rostock University Medical Center, Rostock, Germany
| | - Andreas L Birkenfeld
- Section of Metabolic and Vascular Medicine, Medical Clinic III, Dresden University School of Medicine, Technische Universität Dresden, Germany; Paul Langerhans Institute Dresden of the Helmholtz Center Munich at University Hospital and Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; Center for Systems Neuroscience, 30559 Hannover, Germany.
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25
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Martínez-Glez V, Tenorio J, Nevado J, Gordo G, Rodríguez-Laguna L, Feito M, de Lucas R, Pérez-Jurado LA, Ruiz Pérez VL, Torrelo A, Spinner NB, Happle R, Biesecker LG, Lapunzina P. A six-attribute classification of genetic mosaicism. Genet Med 2020; 22:1743-1757. [PMID: 32661356 PMCID: PMC8581815 DOI: 10.1038/s41436-020-0877-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 06/12/2020] [Accepted: 06/12/2020] [Indexed: 01/23/2023] Open
Abstract
Mosaicism denotes an individual who has at least two populations of cells with distinct genotypes that are derived from a single fertilized egg. Genetic variation among the cell lines can involve whole chromosomes, structural or copy number variants, small or single nucleotide variants, or epigenetic variants. The mutational events that underlie mosaic variants occur during mitotic cell divisions after fertilization and zygote formation. The initiating mutational event can occur in any types of cell at any time in development, leading to enormous variation in the distribution and phenotypic effect of mosaicism. A number of classification proposals have been put forward to classify genetic mosaicism into categories based on the location, pattern, and mechanisms of the disease. We here propose a new classification of genetic mosaicism that considers the affected tissue, the pattern and distribution of the mosaicism, the pathogenicity of the variant, the direction of the change (benign to pathogenic vs. pathogenic to benign), and the postzygotic mutational mechanism. The accurate and comprehensive categorization and subtyping of mosaicisms is important and has potential clinical utility to define the natural history of these disorders, tailor follow-up frequency and interventions, estimate recurrence risks, and guide therapeutic decisions.
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Affiliation(s)
- Víctor Martínez-Glez
- CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Madrid, Spain. .,Institute of Medical and Molecular Genetics (INGEMM)-IdiPAZ, Hospital Universitario La Paz-UAM, Madrid, Spain. .,ITHACA, European Reference Network on Rare Congenital Malformations and Rare Intellectual Disability, Brussels, Belgium.
| | - Jair Tenorio
- CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Madrid, Spain.,Institute of Medical and Molecular Genetics (INGEMM)-IdiPAZ, Hospital Universitario La Paz-UAM, Madrid, Spain.,ITHACA, European Reference Network on Rare Congenital Malformations and Rare Intellectual Disability, Brussels, Belgium
| | - Julián Nevado
- CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Madrid, Spain.,Institute of Medical and Molecular Genetics (INGEMM)-IdiPAZ, Hospital Universitario La Paz-UAM, Madrid, Spain.,ITHACA, European Reference Network on Rare Congenital Malformations and Rare Intellectual Disability, Brussels, Belgium
| | - Gema Gordo
- CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Madrid, Spain.,Institute of Medical and Molecular Genetics (INGEMM)-IdiPAZ, Hospital Universitario La Paz-UAM, Madrid, Spain
| | - Lara Rodríguez-Laguna
- CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Madrid, Spain.,Institute of Medical and Molecular Genetics (INGEMM)-IdiPAZ, Hospital Universitario La Paz-UAM, Madrid, Spain
| | - Marta Feito
- Department of Pediatric Dermatology, Hospital Universitario La Paz-UAM, Madrid, Spain
| | - Raúl de Lucas
- Department of Pediatric Dermatology, Hospital Universitario La Paz-UAM, Madrid, Spain
| | - Luis A Pérez-Jurado
- CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Madrid, Spain.,Genetics Unit, Universitat Pompeu Fabra and Hospital del Mar Research Institute (IMIM), Barcelona, Spain.,Women's and Children's Hospital, South Australia Medical and Health Research Institute (SAHMRI) and University of Adelaide, Adelaide, SA, Australia
| | - Víctor L Ruiz Pérez
- CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Madrid, Spain.,ITHACA, European Reference Network on Rare Congenital Malformations and Rare Intellectual Disability, Brussels, Belgium.,Instituto de Investigaciones Biomédicas de Madrid (CSIC-UAM), Madrid, Spain
| | - Antonio Torrelo
- Department of Pediatrics, Hospital Universitario Niño Jesús, Madrid, Spain
| | - Nancy B Spinner
- Division of Genomic Diagnostics, Department of Pathology and Laboratory Medicines at The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Rudolf Happle
- Department of Dermatology, Medical Center-University of Freiburg, Freiburg, Germany
| | - Leslie G Biesecker
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute (NHGRI), National Institutes of Health, Bethesda, MD, USA
| | - Pablo Lapunzina
- CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Madrid, Spain. .,Institute of Medical and Molecular Genetics (INGEMM)-IdiPAZ, Hospital Universitario La Paz-UAM, Madrid, Spain. .,ITHACA, European Reference Network on Rare Congenital Malformations and Rare Intellectual Disability, Brussels, Belgium.
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26
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Jourdon A, Fasching L, Scuderi S, Abyzov A, Vaccarino FM. The role of somatic mosaicism in brain disease. Curr Opin Genet Dev 2020; 65:84-90. [PMID: 32622340 DOI: 10.1016/j.gde.2020.05.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 04/26/2020] [Accepted: 05/03/2020] [Indexed: 12/25/2022]
Abstract
In this review we discuss the importance of genetic somatic mosaicism and its impact on brain diseases. We start from introducing the different types of somatic mutations, their frequencies and abundances across development and lifespan. We then describe how weakness in DNA repair mechanisms influences their prevalence. Finally, we address their functional consequences in the brain and review recent research showing their unsuspected importance in several neurodevelopmental, psychiatric, and neurodegenerative diseases.
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Affiliation(s)
| | - Liana Fasching
- Child Study Center, Yale University, New Haven, CT 06520, USA
| | - Soraya Scuderi
- Child Study Center, Yale University, New Haven, CT 06520, USA
| | - Alexej Abyzov
- Department of Health Sciences Research, Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Flora M Vaccarino
- Child Study Center, Yale University, New Haven, CT 06520, USA; Department of Neuroscience, Yale University, New Haven, CT 06520, USA.
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27
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Yang X, Chen J, Zheng B, Liu X, Cao Z, Wang X. PCDH19-Related Epilepsy in Early Onset of Chinese Male Patient: Case Report and Literature Review. Front Neurol 2020; 11:311. [PMID: 32425876 PMCID: PMC7203462 DOI: 10.3389/fneur.2020.00311] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Accepted: 03/31/2020] [Indexed: 11/29/2022] Open
Abstract
Mutations in PCDH19 are associated with epilepsy, intellectual disability and behavioral disturbances, mostly related to females. The unique X-linked pattern of inheritance affects females predominantly, while usually is transmitted through asymptomatic males. Recently, new research has demonstrated that males with a mosaic pattern of inheritance could also be affected. As yet, PCDH19 mutations have been reported in hundreds of females; however, only 15 mosaic males were reported to exhibit epileptic seizures with the onset ranges between 6 and 31 months. These patients were usually reported to carry various mutations in the PCDH19. Here we describe a non-sense variant at the PCDH19 (c.498C>G; p.Y166*) in the Chinese male that exhibited early developmental delay and frequent seizures starting from the age of 5 months. We aim that this case report, focusing on studying clinical seizures, therapeutic approaches, and the patient's prognosis, will contribute to the cumulative knowledge of this rare and complex genetic disorder.
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Affiliation(s)
- Xiao Yang
- Department of Neurology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Jing Chen
- Department of Neurology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - BiXia Zheng
- Department of Neurology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Xianyu Liu
- Department of Neurology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Zixuan Cao
- Department of Neurology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Xiaoyu Wang
- Department of Neurology, Children's Hospital of Nanjing Medical University, Nanjing, China
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Dadali EL, Mishina IA, Borovikov AO, Sharkov AA, Kanivets IV. [Clinical and genetic characteristics of epilepsy caused by mutations in the PCDH19 gene (OMIM: 300088)]. Zh Nevrol Psikhiatr Im S S Korsakova 2020; 120:55-61. [PMID: 32105270 DOI: 10.17116/jnevro202012001155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
AIM To analyze clinical and genetic characteristics of PCDH19-associated epilepsy in a sample of patients from the Russian population. MATERIAL AND METHODS The sample of patients with early epileptic encephalopathies included 16 people aged 10 month to 30 years. All patients underwent neurological examination according to standard methods, exome sequencing and EEG monitoring. RESULTS Most of the identified mutations led to a shift in the reading frame or the formation of a termination codon. Six of them were duplications, four were deletions of one nucleotide, and three were nonsense mutations. Consistent with earlier studies, the authors identified the polymorphism of clinical manifestations of seizures that did not depend on the type of mutation and its localization. CONCLUSION Based on the study of the clinical and genetic characteristics of the patients, the authors conclude that the so-called 'hot spots' are present in the PCDH19 gene, which are more common in the group of patients with mutations in this gene, and that the clinical picture of early infantile epileptic encephalopathy type 9 is variable.
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Affiliation(s)
- E L Dadali
- Federal State Budgetary Institution 'Research Centre for Medical Genetics', Moscow, Russia; Pirogov Russian National Research Medical University, Moscow, Russia
| | - I A Mishina
- Federal State Budgetary Institution 'Research Centre for Medical Genetics', Moscow, Russia
| | - A O Borovikov
- Federal State Budgetary Institution 'Research Centre for Medical Genetics', Moscow, Russia
| | - A A Sharkov
- Pirogov Russian National Research Medical University, Moscow, Russia
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Abstract
PURPOSE OF REVIEW There has been rapid progress in defining novel causative gene variants responsible for a large spectrum of human epilepsy syndromes and subtypes. Of particular interest is the discovery that somatic mutations, for example, noninherited mutations occurring in neuroglial progenitor cells during embryonic brain development, are highly linked to malformations of cortical development (MCD) such as focal cortical dysplasia (FCD) type II and hemimegalencephaly. RECENT FINDINGS Somatic gene variants have been identified in genes encoding regulatory proteins within the mechanistic target of rapamycin (mTOR) signaling cascade and have thus comprised the group classified as mTORopathies. FCD II and hemimegalencephaly often result from mutations in identical genes suggesting that these are spectrum disorders. An exciting recent development has been the identification of somatic mutations causing both FCD Ia and nonlesional neocortical epilepsy. SUMMARY Defining somatic gene mutations in brain tissue specimens has shed new light on how MCD form and the mechanisms of epileptogenesis associated with MCD. Trials of mTOR inhibitors in tuberous sclerosis complex have demonstrated that inhibition of mTOR activation in mTORopathies can reduce seizure frequency. New somatic mutations found for a variety of epilepsy syndromes may provide new targets for clinical therapeutics.
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Martin P, Wagh V, Reis SA, Erdin S, Beauchamp RL, Shaikh G, Talkowski M, Thiele E, Sheridan SD, Haggarty SJ, Ramesh V. TSC patient-derived isogenic neural progenitor cells reveal altered early neurodevelopmental phenotypes and rapamycin-induced MNK-eIF4E signaling. Mol Autism 2020; 11:2. [PMID: 31921404 PMCID: PMC6945400 DOI: 10.1186/s13229-019-0311-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 12/29/2019] [Indexed: 12/21/2022] Open
Abstract
Background Tuberous sclerosis complex (TSC) is a neurodevelopmental disorder with frequent occurrence of epilepsy, autism spectrum disorder (ASD), intellectual disability (ID), and tumors in multiple organs. The aberrant activation of mTORC1 in TSC has led to treatment with mTORC1 inhibitor rapamycin as a lifelong therapy for tumors, but TSC-associated neurocognitive manifestations remain unaffected by rapamycin. Methods Here, we generated patient-specific, induced pluripotent stem cells (iPSCs) from a TSC patient with a heterozygous, germline, nonsense mutation in exon 15 of TSC1 and established an isogenic set of heterozygous (Het), null and corrected wildtype (Corr-WT) iPSCs using CRISPR/Cas9-mediated gene editing. We differentiated these iPSCs into neural progenitor cells (NPCs) and examined neurodevelopmental phenotypes, signaling and changes in gene expression by RNA-seq. Results Differentiated NPCs revealed enlarged cell size in TSC1-Het and Null NPCs, consistent with mTORC1 activation. TSC1-Het and Null NPCs also revealed enhanced proliferation and altered neurite outgrowth in a genotype-dependent manner, which was not reversed by rapamycin. Transcriptome analyses of TSC1-NPCs revealed differentially expressed genes that display a genotype-dependent linear response, i.e., genes upregulated/downregulated in Het were further increased/decreased in Null. In particular, genes linked to ASD, epilepsy, and ID were significantly upregulated or downregulated warranting further investigation. In TSC1-Het and Null NPCs, we also observed basal activation of ERK1/2, which was further activated upon rapamycin treatment. Rapamycin also increased MNK1/2-eIF4E signaling in TSC1-deficient NPCs. Conclusion MEK-ERK and MNK-eIF4E pathways regulate protein translation, and our results suggest that aberrant translation distinct in TSC1/2-deficient NPCs could play a role in neurodevelopmental defects. Our data showing upregulation of these signaling pathways by rapamycin support a strategy to combine a MEK or a MNK inhibitor with rapamycin that may be superior for TSC-associated CNS defects. Importantly, our generation of isogenic sets of NPCs from TSC patients provides a valuable platform for translatome and large-scale drug screening studies. Overall, our studies further support the notion that early developmental events such as NPC proliferation and initial process formation, such as neurite number and length that occur prior to neuronal differentiation, represent primary events in neurogenesis critical to disease pathogenesis of neurodevelopmental disorders such as ASD.
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Affiliation(s)
- Pauline Martin
- 1Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA
| | - Vilas Wagh
- 2MERCK Research Laboratories, Boston, MA 02115 USA
| | - Surya A Reis
- 1Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA
| | - Serkan Erdin
- 1Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA
| | - Roberta L Beauchamp
- 1Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA
| | - Ghalib Shaikh
- 1Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA
| | - Michael Talkowski
- 1Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA.,3Department of Neurology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114 USA
| | - Elizabeth Thiele
- 3Department of Neurology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114 USA
| | - Steven D Sheridan
- 1Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA.,4Center for Quantitative Health, Massachusetts General Hospital, Boston, MA 02114 USA
| | - Stephen J Haggarty
- 1Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA.,3Department of Neurology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114 USA
| | - Vijaya Ramesh
- 1Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA.,3Department of Neurology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114 USA
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31
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Kolc KL, Møller RS, Sadleir LG, Scheffer IE, Kumar R, Gecz J. PCDH19 Pathogenic Variants in Males: Expanding the Phenotypic Spectrum. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1298:177-187. [PMID: 32852734 DOI: 10.1007/5584_2020_574] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Protocadherin-19 (PCDH19) pathogenic variants cause an infantile onset epilepsy syndrome called Girls Clustering Epilepsy due to the vast majority of affected individuals being female. This syndromic name was developed to foster early recognition and diagnosis in infancy. It has, however, sparked debate, as, there are rare males with postzygotic somatic, and therefore, mosaic, PCDH19 pathogenic variants with similar clinical features to females. Conversely, "transmitting" males with germline inherited PCDH19 variants are considered asymptomatic. To date, there has been no standardized neuropsychiatric assessment of males with PCDH19 pathogenic variants. Here, we studied 15 males with PCDH19 pathogenic variants (nine mosaic and six transmitting) aged 2 to 70 years. Our families completed a survey including standardized clinical assessments: Social Responsiveness Scale, Strengths and Difficulties Questionnaire, Behavior Rating Inventory of Executive Function, and Dimensional Obsessive-Compulsive Scale. We identified neuropsychiatric abnormalities in two males with germline PCDH19 possibly pathogenic variants. One had a prior history of a severe encephalopathic illness, which may have been unrelated. We also describe a non-penetrant somatic mosaic male with mosaicism confirmed in blood, but not identified in skin fibroblasts. Our data suggest that transmitting hemizygous males are generally unaffected, in contrast to males with postzygotic somatic mosaic variants who show a similar neuropsychiatric profile to females who are naturally mosaic, due to X-chromosome inactivation. The penetrance of PCDH19 pathogenic variants has been estimated to be 80%. Like females, not all mosaic males are affected. From our small sample, we estimate that males with mosaic PCHD19 pathogenic variants have a penetrance of 85%. With these insights into the male phenotypic spectrum of PCDH19 epilepsy, we propose the new term Clustering Epilepsy (CE). Both affected females and males typically present with infantile onset of clusters of seizures.
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Affiliation(s)
- Kristy L Kolc
- Adelaide Medical School, the University of Adelaide, Adelaide, SA, Australia.,Robinson Research Institute, the University of Adelaide, Adelaide, SA, Australia
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Medicine, The Danish Epilepsy Centre, Dianalund, Denmark.,Department for Regional Health Research, University of Southern Denmark, Odense, Denmark
| | - Lynette G Sadleir
- Department of Paediatrics and Child Health, University of Otago, Wellington, New Zealand
| | - Ingrid E Scheffer
- Department of Medicine, Epilepsy Research Centre, The University of Melbourne, Austin Health, Melbourne, VIC, Australia.,Department of Paediatrics, Royal Children's Hospital, The University of Melbourne, Melbourne, VIC, Australia.,The Florey and Murdoch Institutes, Melbourne, VIC, Australia
| | - Raman Kumar
- Adelaide Medical School, the University of Adelaide, Adelaide, SA, Australia.,Robinson Research Institute, the University of Adelaide, Adelaide, SA, Australia
| | - Jozef Gecz
- Adelaide Medical School, the University of Adelaide, Adelaide, SA, Australia. .,Robinson Research Institute, the University of Adelaide, Adelaide, SA, Australia. .,Healthy Mothers and Babies, South Australian Health and Medical Research Institute, Adelaide, SA, Australia.
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32
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Trivisano M, Specchio N. The role of PCDH19 in refractory status epilepticus. Epilepsy Behav 2019; 101:106539. [PMID: 31678000 DOI: 10.1016/j.yebeh.2019.106539] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 09/03/2019] [Indexed: 01/20/2023]
Abstract
PCDH19-Girls Clustering Epilepsy (GCE) is an epileptic syndrome with infantile onset, characterized by clustered and fever-induced seizures, often associated with intellectual disability (ID) and autistic features. Seizures clusters could progress into status epilepticus (SE) with different semiology, both convulsive and nonconvulsive SE (NCSE), and often refractory to conventional antiepileptic drugs. We reviewed literature on PCDH19-GCE, in order to define prevalence, semiology, treatments, and outcome of SE. We conducted a comprehensive review of the PCDH19-GCE literature on the public databases PubMed and EMBASE from January 2008 to July 2019. An overall number of 59 full-text articles were selected, retrieved, and assessed for eligibility. We collected 269 cases with PCDH19-GCE, in 85 of them, a history of SE was reported. Prevalence of SE in all selected series of PCDH19-GCE series is 31.5%. Data on SE were fully exhaustive in 21 cases. There was no gender difference in SE occurrence. Median age at first SE occurrence was 12 months (6 months-11 years). Semiology of SE was reported in 17 cases: it was convulsive in 15 and nonconvulsive in 2. Status epilepticus was refractory in 15 out of 21 cases (71.4%). Benzodiazepine was the most commonly used drug for SE. Alternative treatments with steroids and ketogenic diet were reported as well. We found a high prevalence of ID and autism (19 out of 21 patients, 90%). Despite the relatively high frequency of SE in those patients, there are few specific descriptions of the semiology, EEG pattern, and treatment approach. We strongly believe that a multicenter study looking specifically at SE characteristics might improve the knowledge and consequently the overall outcome. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures".
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Affiliation(s)
- Marina Trivisano
- Rare and Complex Epilepsy Unit, Department of Neuroscience and Neurorehabilitation, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Nicola Specchio
- Rare and Complex Epilepsy Unit, Department of Neuroscience and Neurorehabilitation, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
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33
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Du S, Yang Y, Yi P, Luo J, Liu T, Chen R, Liu CJ, Ma T, Li Y, Wang C, Weng J, Liu M, Zhang L, Yang B, Zeng X, Liu JY. A Novel CDH1 Mutation Causing Reduced E-Cadherin Dimerization Is Associated with Nonsyndromic Cleft Lip With or Without Cleft Palate. Genet Test Mol Biomarkers 2019; 23:759-765. [PMID: 31638429 DOI: 10.1089/gtmb.2019.0092] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Aims: Cleft lip with or without cleft palate (CL/P) is a common birth defect with an average prevalence of 1/700 to 1/1000. Almost 70% of CL/P cases are nonsyndromic CL/P (NSCL/P). The aim of this study was to identify the underlying cause of a four-generation Chinese family with autosomal dominant NSCL/P. Methods: Genomic DNA was extracted from peripheral blood leukocytes, and whole-exome sequencing was carried out to identify the underlying genetic cause of the disorder. The mutation was confirmed by Sanger sequencing and polymerase chain reaction-restriction fragment length polymorphism methods. Western blotting and coimmunoprecipitation were used to analyze the protein expression level and adhesive dimerization of the CDH1 mutants. Slow aggregation assays were conducted to investigate the cell-cell adhesion ability. Results: A novel missense mutation (c.468G>C/p.Trp156Cys) of CDH1 was identified in the proband and the mutation was shown to cosegregate with the phenotype in the family. Furthermore, we found that the p.Trp156Cys mutation led to decreased E-cadherin dimerization and cell-cell adhesion ability. Conclusions: Our findings identified a novel CDH1 variant (c.468G>C/p.Trp156Cys) responsible for NSCL/P in a Chinese family, which expanded the mutational spectrum of the CDH1 gene and may contribute to understanding the molecular basis of NSCL/P.
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Affiliation(s)
- Shiyue Du
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Center for Human Genome Research, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Yujie Yang
- Department of Neurology & National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Ping Yi
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Center for Human Genome Research, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Junyu Luo
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Center for Human Genome Research, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Teng Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Center for Human Genome Research, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Rui Chen
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Center for Human Genome Research, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Chun-Jie Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Center for Human Genome Research, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Tingbin Ma
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Center for Human Genome Research, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Yulei Li
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Center for Human Genome Research, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Cheng Wang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Center for Human Genome Research, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Jun Weng
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Center for Human Genome Research, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Mugen Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Center for Human Genome Research, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Luoying Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Center for Human Genome Research, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Baosheng Yang
- Sanquan College, Xinxiang Medical University, Xinxiang, China
| | - Xiaomei Zeng
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Center for Human Genome Research, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Jing Yu Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Center for Human Genome Research, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
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34
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Yang X, Yang X, Chen J, Li S, Zeng Q, Huang AY, Ye AY, Yu Z, Wang S, Jiang Y, Wu X, Wu Q, Wei L, Zhang Y. ATP1A3 mosaicism in families with alternating hemiplegia of childhood. Clin Genet 2019; 96:43-52. [PMID: 30891744 PMCID: PMC6850116 DOI: 10.1111/cge.13539] [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: 12/22/2018] [Revised: 03/10/2019] [Accepted: 03/15/2019] [Indexed: 01/17/2023]
Abstract
Alternating hemiplegia of childhood (AHC) is a rare and severe neurodevelopmental disorder characterized by recurrent hemiplegic episodes. Most AHC cases are sporadic and caused by de novo ATP1A3 pathogenic variants. In this study, the aim was to identify the origin of ATP1A3 pathogenic variants in a Chinese cohort. In 105 probands including 101 sporadic and 4 familial cases, 98 patients with ATP1A3 pathogenic variants were identified, and 96.8% were confirmed as de novo. Micro-droplet digital polymerase chain reaction was applied for detecting ATP1A3 mosaicism in 80 available families. In blood samples, four asymptomatic parents, including two paternal and two maternal, and one proband with a milder phenotype were identified as mosaicism. Six (7.5%) parental mosaicisms were identified in multiple tissues, including four previously identified in blood and two additional cases identified from paternal sperms. Mosaicism was identified in multiple tissues with varied mutant allele fractions (MAFs, 0.03%-33.03%). The results suggested that MAF of mosaicism may be related to phenotype severity. This is the first systematic report of ATP1A3 mosaicism in AHC and showed mosaicism as an unrecognized source of previously considered "de novo" AHC. Identifying ATP1A3 mosaicism provides more evidence for estimating recurrence risk and has implications in genetic counseling of AHC.
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Affiliation(s)
- Xiaoling Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xiaoxu Yang
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Jiaoyang Chen
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Shupin Li
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Qi Zeng
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - August Y Huang
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Adam Y Ye
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China.,Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Zhe Yu
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Sheng Wang
- Dr Liping Wei's lab, National Institute of Biological Sciences, Beijing, China.,College of Biological Sciences, China Agricultural University, Beijing, China
| | - Yuwu Jiang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xiru Wu
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Qixi Wu
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China.,Human Genetic Resources Core Facility, School of Life Sciences, Peking University, Beijing, China
| | - Liping Wei
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Yuehua Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
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