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Cheng J, Wang Z, Tang M, Zhang W, Li G, Tan S, Mu C, Hu M, Zhang D, Jia X, Wen Y, Guo H, Xu D, Liu L, Li J, Xia K, Li F, Duan R, Xu Z, Yuan L. KCTD10 regulates brain development by destabilizing brain disorder-associated protein KCTD13. Proc Natl Acad Sci U S A 2024; 121:e2315707121. [PMID: 38489388 PMCID: PMC10963008 DOI: 10.1073/pnas.2315707121] [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: 09/10/2023] [Accepted: 02/02/2024] [Indexed: 03/17/2024] Open
Abstract
KCTD10 belongs to the KCTD (potassiumchannel tetramerization domain) family, many members of which are associated with neuropsychiatric disorders. However, the biological function underlying the association with brain disorders remains to be explored. Here, we reveal that Kctd10 is highly expressed in neuronal progenitors and layer V neurons throughout brain development. Kctd10 deficiency triggers abnormal proliferation and differentiation of neuronal progenitors, reduced deep-layer (especially layer V) neurons, increased upper-layer neurons, and lowered brain size. Mechanistically, we screened and identified a unique KCTD10-interacting protein, KCTD13, associated with neurodevelopmental disorders. KCTD10 mediated the ubiquitination-dependent degradation of KCTD13 and KCTD10 ablation resulted in a considerable increase of KCTD13 expression in the developing cortex. KCTD13 overexpression in neuronal progenitors led to reduced proliferation and abnormal cell distribution, mirroring KCTD10 deficiency. Notably, mice with brain-specific Kctd10 knockout exhibited obvious motor deficits. This study uncovers the physiological function of KCTD10 and provides unique insights into the pathogenesis of neurodevelopmental disorders.
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Affiliation(s)
- Jianbo Cheng
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics, Key Lab of Rare Pediatric Diseases of Ministry of Education, School of Life Sciences, Central South University, Changsha, Hunan410078, China
| | - Zhen Wang
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics, Key Lab of Rare Pediatric Diseases of Ministry of Education, School of Life Sciences, Central South University, Changsha, Hunan410078, China
| | - Manpei Tang
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics, Key Lab of Rare Pediatric Diseases of Ministry of Education, School of Life Sciences, Central South University, Changsha, Hunan410078, China
| | - Wen Zhang
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics, Key Lab of Rare Pediatric Diseases of Ministry of Education, School of Life Sciences, Central South University, Changsha, Hunan410078, China
| | - Guozhong Li
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics, Key Lab of Rare Pediatric Diseases of Ministry of Education, School of Life Sciences, Central South University, Changsha, Hunan410078, China
| | - Senwei Tan
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics, Key Lab of Rare Pediatric Diseases of Ministry of Education, School of Life Sciences, Central South University, Changsha, Hunan410078, China
| | - Chenjun Mu
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics, Key Lab of Rare Pediatric Diseases of Ministry of Education, School of Life Sciences, Central South University, Changsha, Hunan410078, China
| | - Mengyuan Hu
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics, Key Lab of Rare Pediatric Diseases of Ministry of Education, School of Life Sciences, Central South University, Changsha, Hunan410078, China
| | - Dan Zhang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing100101, China
| | - Xiangbin Jia
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics, Key Lab of Rare Pediatric Diseases of Ministry of Education, School of Life Sciences, Central South University, Changsha, Hunan410078, China
| | - Yangxuan Wen
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics, Key Lab of Rare Pediatric Diseases of Ministry of Education, School of Life Sciences, Central South University, Changsha, Hunan410078, China
| | - Hui Guo
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics, Key Lab of Rare Pediatric Diseases of Ministry of Education, School of Life Sciences, Central South University, Changsha, Hunan410078, China
- Hunan Key Laboratory of Animal Models for Human Diseases, Central South University, Changsha, Hunan410078, China
| | - Dan Xu
- Fujian Key Laboratory of Molecular Neurology, Institute of Neuroscience, Fujian Medical University, Fuzhou350005, China
| | - Liang Liu
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing100053, China
| | - Jiada Li
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics, Key Lab of Rare Pediatric Diseases of Ministry of Education, School of Life Sciences, Central South University, Changsha, Hunan410078, China
- Hunan Key Laboratory of Animal Models for Human Diseases, Central South University, Changsha, Hunan410078, China
| | - Kun Xia
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics, Key Lab of Rare Pediatric Diseases of Ministry of Education, School of Life Sciences, Central South University, Changsha, Hunan410078, China
- Hunan Key Laboratory of Animal Models for Human Diseases, Central South University, Changsha, Hunan410078, China
| | - Faxiang Li
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics, Key Lab of Rare Pediatric Diseases of Ministry of Education, School of Life Sciences, Central South University, Changsha, Hunan410078, China
- Hunan Key Laboratory of Animal Models for Human Diseases, Central South University, Changsha, Hunan410078, China
| | - Ranhui Duan
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics, Key Lab of Rare Pediatric Diseases of Ministry of Education, School of Life Sciences, Central South University, Changsha, Hunan410078, China
- Hunan Key Laboratory of Animal Models for Human Diseases, Central South University, Changsha, Hunan410078, China
| | - Zhiheng Xu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing100101, China
| | - Ling Yuan
- Center for Medical Genetics, Hunan Key Laboratory of Medical Genetics, Key Lab of Rare Pediatric Diseases of Ministry of Education, School of Life Sciences, Central South University, Changsha, Hunan410078, China
- Hunan Key Laboratory of Animal Models for Human Diseases, Central South University, Changsha, Hunan410078, China
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Yoganathan S, Whitney R, Thomas M, Danda S, Chettali AM, Prasad AN, Farhan SMK, AlSowat D, Abukhaled M, Aldhalaan H, Gowda VK, Kinhal UV, Bylappa AY, Konanki R, Lingappa L, Parchuri BM, Appendino JP, Scantlebury MH, Cunningham J, Hadjinicolaou A, El Achkar CM, Kamate M, Menon RN, Jose M, Riordan G, Kannan L, Jain V, Manokaran RK, Chau V, Donner EJ, Costain G, Minassian BA, Jain P. KCTD7-related progressive myoclonic epilepsy: Report of 42 cases and review of literature. Epilepsia 2024; 65:709-724. [PMID: 38231304 DOI: 10.1111/epi.17880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 01/02/2024] [Accepted: 01/03/2024] [Indexed: 01/18/2024]
Abstract
OBJECTIVE KCTD7-related progressive myoclonic epilepsy (PME) is a rare autosomal-recessive disorder. This study aimed to describe the clinical details and genetic variants in a large international cohort. METHODS Families with molecularly confirmed diagnoses of KCTD7-related PME were identified through international collaboration. Furthermore, a systematic review was done to identify previously reported cases. Salient demographic, epilepsy, treatment, genetic testing, electroencephalographic (EEG), and imaging-related variables were collected and summarized. RESULTS Forty-two patients (36 families) were included. The median age at first seizure was 14 months (interquartile range = 11.75-22.5). Myoclonic seizures were frequently the first seizure type noted (n = 18, 43.9%). EEG and brain magnetic resonance imaging findings were variable. Many patients exhibited delayed development with subsequent progressive regression (n = 16, 38.1%). Twenty-one cases with genetic testing available (55%) had previously reported variants in KCTD7, and 17 cases (45%) had novel variants in KCTD7 gene. Six patients died in the cohort (age range = 1.5-21 years). The systematic review identified 23 eligible studies and further identified 59 previously reported cases of KCTD7-related disorders from the literature. The phenotype for the majority of the reported cases was consistent with a PME (n = 52, 88%). Other reported phenotypes in the literature included opsoclonus myoclonus ataxia syndrome (n = 2), myoclonus dystonia (n = 2), and neuronal ceroid lipofuscinosis (n = 3). Eight published cases died over time (14%, age range = 3-18 years). SIGNIFICANCE This study cohort and systematic review consolidated the phenotypic spectrum and natural history of KCTD7-related disorders. Early onset drug-resistant epilepsy, relentless neuroregression, and severe neurological sequalae were common. Better understanding of the natural history may help future clinical trials.
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Affiliation(s)
- Sangeetha Yoganathan
- Department of Neurological Sciences, Christian Medical College, Vellore, Tamil Nadu, India
| | - Robyn Whitney
- Comprehensive Pediatric Epilepsy Program, Division of Neurology, Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| | - Maya Thomas
- Department of Neurological Sciences, Christian Medical College, Vellore, Tamil Nadu, India
| | - Sumita Danda
- Department of Medical Genetics, Christian Medical College, Vellore, Tamil Nadu, India
| | | | - Asuri N Prasad
- Division of Pediatric Neurology and Clinical Neurosciences, Department of Pediatrics, Children's Hospital, London Health Sciences Centre, London, Ontario, Canada
| | - Sali M K Farhan
- Department of Neurology and Neurosurgery, and Department of Human Genetics, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Daad AlSowat
- Division of Pediatric Neurology, Neurosciences Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Musaad Abukhaled
- Division of Pediatric Neurology, Neurosciences Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hesham Aldhalaan
- Division of Pediatric Neurology, Neurosciences Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Vykuntaraju K Gowda
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
| | - Uddhava V Kinhal
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
| | - Arun Y Bylappa
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
| | - Ramesh Konanki
- Department of Pediatric Neurology, Rainbow Children's Hospital, Hyderabad, Telangana, India
| | - Lokesh Lingappa
- Department of Pediatric Neurology, Rainbow Children's Hospital, Hyderabad, Telangana, India
| | | | - Juan P Appendino
- Pediatric Neurology Service, Department of Pediatrics, Cumming School of Medicine, University of Calgary, Alberta Children's Hospital, Calgary, Alberta, Canada
| | - Morris H Scantlebury
- Departments of Pediatrics and Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Jessie Cunningham
- Hospital Library and Archives, Learning Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Aristides Hadjinicolaou
- Division of Neurology, Department of Pediatrics, CHU (Centre Hospitalier Universitaire) Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada
| | - Christelle Moufawad El Achkar
- Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Mahesh Kamate
- Department of Pediatric Neurology, Jawaharlal Nehru Medical College, KLE (Karnataka Lingayat Education) Academy of Higher Education and Research, KLE's Dr Prabhakar Kore (PK) Hospital, Belagavi, Karnataka, India
| | - Ramshekhar N Menon
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences & Technology, Thiruvananthapuram, Kerala, India
| | - Manna Jose
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences & Technology, Thiruvananthapuram, Kerala, India
| | - Gillian Riordan
- Department of Paediatric Neurology, Red Cross War Memorial Children's Hospital, University of Cape Town, Cape Town, South Africa
| | | | - Vivek Jain
- Department of Pediatric Neurology, Neoclinic Children's Hospital, Jaipur, Rajasthan, India
| | - Ranjith Kumar Manokaran
- Division of Pediatric neurology, Department of Neurology, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
| | - Vann Chau
- Division of Neurology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Elizabeth J Donner
- Epilepsy Program, Division of Neurology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Gregory Costain
- Division of Clinical and Metabolic Genetics, Hospital for Sick Children, and Program in Genetics & Genome Biology, SickKids Research Institute, Toronto, Ontario, Canada
| | - Berge A Minassian
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Puneet Jain
- Epilepsy Program, Division of Neurology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
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Ilyas M, Tariq F, Ishaq R, Habiba U, Bibi F, Khan SN, Ali Y, Haider S, Efthymiou S, Abdullah U, Raja GK, Shaiq PA. Whole exome sequencing identifies variable expressivity of CLN6 variants in Progressive myoclonic epilepsy affected families. Epilepsy Res 2024; 201:107283. [PMID: 38382230 DOI: 10.1016/j.eplepsyres.2023.107283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 11/25/2023] [Accepted: 12/14/2023] [Indexed: 02/23/2024]
Abstract
Progressive myoclonic epilepsies (PMEs) are a group of neurodegenerative disorders, predominantly affecting adolescents and, characterized by generalized worsening myoclonus epilepsies, ataxia, cognitive deficits, and dementia. To date, several genes, having implications in diverse phenotypic expressions associated with PMEs, have been identified. Genetic diagnosis is available for most of the adolescence-onset myoclonic epilepsies. This study aimed to elucidate the genetic basis of PMEs in three multiplex Pakistani families exhibiting clinically variable phenotypes. Causative variant(s) in the studied families, and mode of segregation were identified by Whole Exome Sequencing (WES) of the probands, followed by bi-directional Sanger sequencing for final validation. We identified homozygous recessive CLN6 missense variant c.768 C>G (p.Asp256Glu) in Family 1, and c.889 C>A (p.Pro297Thr) variant in Family 2. While in Family 3, we found a homozygous variant (c.316dup) that caused a frameshift mutation, leading to a premature stop codon in the CLN6 protein, resulting in a truncated protein (p.Arg106ProfsTer26). Though CLN6 is previously identified to underlie late infantile and adolescent onset neuronal ceroid lipofuscinosis, this study supports and expands the phenotypic spectrum of CLN6 mutations and signifies diagnositc potential CLN6 variants for PMEs. Diverse pathological effects of variant c .768 C>G were observed in Family 1, with same genotypes, suggesting clinical heterogeneity and/or variable expressivity that might be the implication of pleiotropic effects of the gene in these cases.
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Affiliation(s)
- Muhammad Ilyas
- University Institute of Biochemistry and Biotechnology, (PMAS) Pir Mehr Ali Shah Arid Agriculture University Rawalpindi, Pakistan; Department of Medical Laboratory Technology, Riphah International University, Malakand Campus, Khyber Pakhtunkhwa, Pakistan
| | - Faiza Tariq
- University Institute of Biochemistry and Biotechnology, (PMAS) Pir Mehr Ali Shah Arid Agriculture University Rawalpindi, Pakistan
| | - Rafaqat Ishaq
- University Institute of Biochemistry and Biotechnology, (PMAS) Pir Mehr Ali Shah Arid Agriculture University Rawalpindi, Pakistan
| | - Umme Habiba
- University Institute of Biochemistry and Biotechnology, (PMAS) Pir Mehr Ali Shah Arid Agriculture University Rawalpindi, Pakistan
| | - Farah Bibi
- University Institute of Biochemistry and Biotechnology, (PMAS) Pir Mehr Ali Shah Arid Agriculture University Rawalpindi, Pakistan
| | - Sadiq Noor Khan
- Department of Medical Laboratory Technology, University of Haripur, Khyber Pakhtunkhwa, Pakistan
| | - Yasir Ali
- Institute of Chemistry, Solvak Academy of Sciences, 84538 Bratislava, Slovakia
| | - Shehzad Haider
- Wah Medical College, Izzat Ali Shah Hospital, Maternal and Child Health Centre, Wah Cantt, Pakistan
| | | | - Uzma Abdullah
- University Institute of Biochemistry and Biotechnology, (PMAS) Pir Mehr Ali Shah Arid Agriculture University Rawalpindi, Pakistan
| | - Ghazala Kaukab Raja
- University Institute of Biochemistry and Biotechnology, (PMAS) Pir Mehr Ali Shah Arid Agriculture University Rawalpindi, Pakistan
| | - Pakeeza Arzoo Shaiq
- University Institute of Biochemistry and Biotechnology, (PMAS) Pir Mehr Ali Shah Arid Agriculture University Rawalpindi, Pakistan.
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Cameron JM, Ellis CA, Berkovic SF. ILAE Genetics Literacy series: Progressive myoclonus epilepsies. Epileptic Disord 2023; 25:670-680. [PMID: 37616028 PMCID: PMC10947580 DOI: 10.1002/epd2.20152] [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: 04/24/2023] [Revised: 07/21/2023] [Accepted: 08/19/2023] [Indexed: 08/25/2023]
Abstract
Progressive Myoclonus Epilepsy (PME) is a rare epilepsy syndrome characterized by the development of progressively worsening myoclonus, ataxia, and seizures. A molecular diagnosis can now be established in approximately 80% of individuals with PME. Almost fifty genetic causes of PME have now been established, although some remain extremely rare. Herein, we provide a review of clinical phenotypes and genotypes of the more commonly encountered PMEs. Using an illustrative case example, we describe appropriate clinical investigation and therapeutic strategies to guide the management of this often relentlessly progressive and devastating epilepsy syndrome. This manuscript in the Genetic Literacy series maps to Learning Objective 1.2 of the ILAE Curriculum for Epileptology (Epileptic Disord. 2019;21:129).
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Affiliation(s)
- Jillian M. Cameron
- Epilepsy Research Centre, Department of MedicineUniversity of MelbourneAustin HealthMelbourneVictoriaAustralia
| | - Colin A. Ellis
- Department of NeurologyUniversity of Pennsylvania Perelman School of MedicinePhiladelphiaPennsylvaniaUSA
| | - Samuel F. Berkovic
- Epilepsy Research Centre, Department of MedicineUniversity of MelbourneAustin HealthMelbourneVictoriaAustralia
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5
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Bernardi S, Gemignani F, Marchese M. The involvement of Purkinje cells in progressive myoclonic epilepsy: Focus on neuronal ceroid lipofuscinosis. Neurobiol Dis 2023; 185:106258. [PMID: 37573956 PMCID: PMC10480493 DOI: 10.1016/j.nbd.2023.106258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 08/01/2023] [Accepted: 08/11/2023] [Indexed: 08/15/2023] Open
Abstract
The progressive myoclonic epilepsies (PMEs) are a group of rare neurodegenerative diseases characterized by myoclonus, epileptic seizures, and progressive neurological deterioration with cerebellar involvement. They include storage diseases like Gaucher disease, Lafora disease, and forms of neuronal ceroid lipofuscinosis (NCL). To date, 13 NCLs have been reported (CLN1-CLN8, CLN10-CLN14), associated with mutations in different genes. These forms, which affect both children and adults, are characterized by seizures, cognitive and motor impairments, and in most cases visual loss. In NCLs, as in other PMEs, central nervous system (CNS) neurodegeneration is widespread and involves different subpopulations of neurons. One of the most affected regions is the cerebellar cortex, where motor and non-motor information is processed and transmitted to deep cerebellar nuclei through the axons of Purkinje cells (PCs). PCs, being GABAergic, have an inhibitory effect on their target neurons, and provide the only inhibitory output of the cerebellum. Degeneration of PCs has been linked to motor impairments and epileptic seizures. Seizures occur when some insult upsets the normal balance in the CNS between excitatory and inhibitory impulses, causing hyperexcitability. Here we review the role of PCs in epilepsy onset and progression following their PME-related loss. In particular, we focus on the involvement of PCs in seizure phenotype in NCLs, highlighting findings from case reports and studies of animal models in which epilepsy can be linked to PC loss.
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Affiliation(s)
- Sara Bernardi
- Department Neurobiology and Molecular Medicine, IRCCS Fondazione Stella Maris, 56128 Pisa, Italy; Department of Biology, University of Pisa, Pisa, Italy
| | | | - Maria Marchese
- Department Neurobiology and Molecular Medicine, IRCCS Fondazione Stella Maris, 56128 Pisa, Italy.
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6
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Liu J, Rahim F, Zhou J, Fan S, Jiang H, Yu C, Chen J, Xu J, Yang G, Shah W, Zubair M, Khan A, Li Y, Shah B, Zhao D, Iqbal F, Jiang X, Guo T, Xu P, Xu B, Wu L, Ma H, Zhang Y, Zhang H, Shi Q. Loss-of-function variants in KCTD19 cause non-obstructive azoospermia in humans. iScience 2023; 26:107193. [PMID: 37485353 PMCID: PMC10362269 DOI: 10.1016/j.isci.2023.107193] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 04/19/2023] [Accepted: 06/19/2023] [Indexed: 07/25/2023] Open
Abstract
Azoospermia is a significant cause of male infertility, with non-obstructive azoospermia (NOA) being the most severe type of spermatogenic failure. NOA is mostly caused by congenital factors, but our understanding of its genetic causes is very limited. Here, we identified a frameshift variant (c.201_202insAC, p.Tyr68Thrfs∗17) and two nonsense variants (c.1897C>T, p.Gln633∗; c.2005C>T, p.Gln669∗) in KCTD19 (potassium channel tetramerization domain containing 19) from two unrelated infertile Chinese men and a consanguineous Pakistani family with three infertile brothers. Testicular histological analyses revealed meiotic metaphase I (MMI) arrest in the affected individuals. Mice modeling KCTD19 variants recapitulated the same MMI arrest phenotype due to severe disrupted individualization of MMI chromosomes. Further analysis showed a complete loss of KCTD19 protein in both Kctd19 mutant mouse testes and affected individual testes. Collectively, our findings demonstrate the pathogenicity of the identified KCTD19 variants and highlight an essential role of KCTD19 in MMI chromosome individualization.
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Affiliation(s)
- Junyan Liu
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Fazal Rahim
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Jianteng Zhou
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Suixing Fan
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Hanwei Jiang
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Changping Yu
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Jing Chen
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Jianze Xu
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Gang Yang
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Wasim Shah
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Muhammad Zubair
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Asad Khan
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Yang Li
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Basit Shah
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Daren Zhao
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Furhan Iqbal
- Institute of Pure and Applied Biology, Zoology Division, Bahauddin Zakariya University, Multan 60800, Pakistan
| | - Xiaohua Jiang
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Tonghang Guo
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Peng Xu
- Hainan Jinghua Hejing Hospital for Reproductive Medicine, Hainan 570125, China
| | - Bo Xu
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Limin Wu
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Hui Ma
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Yuanwei Zhang
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Huan Zhang
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
| | - Qinghua Shi
- Division of Reproduction and Genetics, First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230027, China
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7
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Klein M, Hermey G. Converging links between adult-onset neurodegenerative Alzheimer's disease and early life neurodegenerative neuronal ceroid lipofuscinosis? Neural Regen Res 2023; 18:1463-1471. [PMID: 36571343 PMCID: PMC10075119 DOI: 10.4103/1673-5374.361544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Evidence from genetics and from analyzing cellular and animal models have converged to suggest links between neurodegenerative disorders of early and late life. Here, we summarize emerging links between the most common late life neurodegenerative disease, Alzheimer's disease, and the most common early life neurodegenerative diseases, neuronal ceroid lipofuscinoses. Genetic studies reported an overlap of clinically diagnosed Alzheimer's disease and mutations in genes known to cause neuronal ceroid lipofuscinoses. Accumulating data strongly suggest dysfunction of intracellular trafficking mechanisms and the autophagy-endolysosome system in both types of neurodegenerative disorders. This suggests shared cytopathological processes underlying these different types of neurodegenerative diseases. A better understanding of the common mechanisms underlying the different diseases is important as this might lead to the identification of novel targets for therapeutic concepts, the transfer of therapeutic strategies from one disease to the other and therapeutic approaches tailored to patients with specific mutations. Here, we review dysfunctions of the endolysosomal autophagy pathway in Alzheimer's disease and neuronal ceroid lipofuscinoses and summarize emerging etiologic and genetic overlaps.
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Affiliation(s)
- Marcel Klein
- Institute for Molecular and Cellular Cognition, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Guido Hermey
- Institute for Molecular and Cellular Cognition, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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8
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Sharma J, Mulherkar S, Chen UI, Xiong Y, Bajaj L, Cho BK, Goo YA, Leung HCE, Tolias KF, Sardiello M. Calpain activity is negatively regulated by a KCTD7-Cullin-3 complex via non-degradative ubiquitination. Cell Discov 2023; 9:32. [PMID: 36964131 PMCID: PMC10038992 DOI: 10.1038/s41421-023-00533-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 02/24/2023] [Indexed: 03/26/2023] Open
Abstract
Calpains are a class of non-lysosomal cysteine proteases that exert their regulatory functions via limited proteolysis of their substrates. Similar to the lysosomal and proteasomal systems, calpain dysregulation is implicated in the pathogenesis of neurodegenerative disease and cancer. Despite intensive efforts placed on the identification of mechanisms that regulate calpains, however, calpain protein modifications that regulate calpain activity are incompletely understood. Here we show that calpains are regulated by KCTD7, a cytosolic protein of previously uncharacterized function whose pathogenic mutations result in epilepsy, progressive ataxia, and severe neurocognitive deterioration. We show that KCTD7 works in complex with Cullin-3 and Rbx1 to execute atypical, non-degradative ubiquitination of calpains at specific sites (K398 of calpain 1, and K280 and K674 of calpain 2). Experiments based on single-lysine mutants of ubiquitin determined that KCTD7 mediates ubiquitination of calpain 1 via K6-, K27-, K29-, and K63-linked chains, whereas it uses K6-mediated ubiquitination to modify calpain 2. Loss of KCTD7-mediated ubiquitination of calpains led to calpain hyperactivation, aberrant cleavage of downstream targets, and caspase-3 activation. CRISPR/Cas9-mediated knockout of Kctd7 in mice phenotypically recapitulated human KCTD7 deficiency and resulted in calpain hyperactivation, behavioral impairments, and neurodegeneration. These phenotypes were largely prevented by pharmacological inhibition of calpains, thus demonstrating a major role of calpain dysregulation in KCTD7-associated disease. Finally, we determined that Cullin-3-KCTD7 mediates ubiquitination of all ubiquitous calpains. These results unveil a novel mechanism and potential target to restrain calpain activity in human disease and shed light on the molecular pathogenesis of KCTD7-associated disease.
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Affiliation(s)
- Jaiprakash Sharma
- Department of Molecular and Human Genetics, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.
- Department of Pediatrics, Washington University in St. Louis, School of Medicine, Genetics and Genomic Medicine, Saint Louis, MO, USA.
| | - Shalaka Mulherkar
- Department of Pediatrics, Washington University in St. Louis, School of Medicine, Genetics and Genomic Medicine, Saint Louis, MO, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Uan-I Chen
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Yan Xiong
- Department of Molecular and Human Genetics, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
- Department of Pediatrics, Washington University in St. Louis, School of Medicine, Genetics and Genomic Medicine, Saint Louis, MO, USA
| | - Lakshya Bajaj
- Department of Molecular and Human Genetics, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Byoung-Kyu Cho
- Mass Spectrometry Technology Access Center at the McDonnell Genome Institute, Washington University in St. Louis, School of Medicine, St. Louis, MO, USA
| | - Young Ah Goo
- Mass Spectrometry Technology Access Center at the McDonnell Genome Institute, Washington University in St. Louis, School of Medicine, St. Louis, MO, USA
- Department of Biochemistry and Molecular Biophysics, Department of Genetics, Washington University School of Medicine, St. Louis, MO, USA
| | - Hon-Chiu Eastwood Leung
- Departments of Medicine, Pediatrics, and Molecular and Cellular Biology, Dan Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - Kimberley F Tolias
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Verna and Marrs McLean Department of Biochemistry and Molecular Cell Biology, Baylor College of Medicine, Houston, TX, USA
| | - Marco Sardiello
- Department of Molecular and Human Genetics, Baylor College of Medicine, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.
- Department of Pediatrics, Washington University in St. Louis, School of Medicine, Genetics and Genomic Medicine, Saint Louis, MO, USA.
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9
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Multiple potassium channel tetramerization domain (KCTD) family members interact with Gβγ, with effects on cAMP signaling. J Biol Chem 2023; 299:102924. [PMID: 36736897 PMCID: PMC9976452 DOI: 10.1016/j.jbc.2023.102924] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 01/04/2023] [Accepted: 01/05/2023] [Indexed: 02/04/2023] Open
Abstract
G protein-coupled receptors (GPCRs) initiate an array of intracellular signaling programs by activating heterotrimeric G proteins (Gα and Gβγ subunits). Therefore, G protein modifiers are well positioned to shape GPCR pharmacology. A few members of the potassium channel tetramerization domain (KCTD) protein family have been found to adjust G protein signaling through interaction with Gβγ. However, comprehensive details on the KCTD interaction with Gβγ remain unresolved. Here, we report that nearly all the 25 KCTD proteins interact with Gβγ. In this study, we screened Gβγ interaction capacity across the entire KCTD family using two parallel approaches. In a live cell bioluminescence resonance energy transfer-based assay, we find that roughly half of KCTD proteins interact with Gβγ in an agonist-induced fashion, whereas all KCTD proteins except two were found to interact through coimmunoprecipitation. We observed that the interaction was dependent on an amino acid hot spot in the C terminus of KCTD2, KCTD5, and KCTD17. While KCTD2 and KCTD5 require both the Bric-à-brac, Tramtrack, Broad complex domain and C-terminal regions for Gβγ interaction, we uncovered that the KCTD17 C terminus is sufficient for Gβγ interaction. Finally, we demonstrated the functional consequence of the KCTD-Gβγ interaction by examining sensitization of the adenylyl cyclase-cAMP pathway in live cells. We found that Gβγ-mediated sensitization of adenylyl cyclase 5 was blunted by KCTD. We conclude that the KCTD family broadly engages Gβγ to shape GPCR signal transmission.
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10
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Progressive myoclonic epilepsies—English Version. ZEITSCHRIFT FÜR EPILEPTOLOGIE 2022. [DOI: 10.1007/s10309-022-00546-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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11
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Liang JH, Alevy J, Akhanov V, Seo R, Massey CA, Jiang D, Zhou J, Sillitoe RV, Noebels JL, Samuel MA. Kctd7 deficiency induces myoclonic seizures associated with Purkinje cell death and microvascular defects. Dis Model Mech 2022; 15:dmm049642. [PMID: 35972048 PMCID: PMC9509889 DOI: 10.1242/dmm.049642] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 07/29/2022] [Indexed: 01/27/2023] Open
Abstract
Mutations in the potassium channel tetramerization domain-containing 7 (KCTD7) gene are associated with a severe neurodegenerative phenotype characterized by childhood onset of progressive and intractable myoclonic seizures accompanied by developmental regression. KCTD7-driven disease is part of a large family of progressive myoclonic epilepsy syndromes displaying a broad spectrum of clinical severity. Animal models of KCTD7-related disease are lacking, and little is known regarding how KCTD7 protein defects lead to epilepsy and cognitive dysfunction. We characterized Kctd7 expression patterns in the mouse brain during development and show that it is selectively enriched in specific regions as the brain matures. We further demonstrate that Kctd7-deficient mice develop seizures and locomotor defects with features similar to those observed in human KCTD7-associated diseases. We also show that Kctd7 is required for Purkinje cell survival in the cerebellum and that selective degeneration of these neurons is accompanied by defects in cerebellar microvascular organization and patterning. Taken together, these results define a new model for KCTD7-associated epilepsy and identify Kctd7 as a modulator of neuron survival and excitability linked to microvascular alterations in vulnerable regions.
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Affiliation(s)
- Justine H. Liang
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jonathan Alevy
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Viktor Akhanov
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ryan Seo
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Developmental Neurogenetics Laboratory, Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Human and Molecular Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Cory A. Massey
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Developmental Neurogenetics Laboratory, Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Human and Molecular Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Danye Jiang
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Joy Zhou
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, TX 77030, USA
| | - Roy V. Sillitoe
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Jan and Dan Duncan Neurological Research Institute of Texas Children's Hospital, Houston, TX 77030, USA
| | - Jeffrey L. Noebels
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Developmental Neurogenetics Laboratory, Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Human and Molecular Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Melanie A. Samuel
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
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12
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Wang Y, Cao X, Liu P, Zeng W, Peng R, Shi Q, Feng K, Zhang P, Sun H, Wang C, Wang H. KCTD7 mutations impair the trafficking of lysosomal enzymes through CLN5 accumulation to cause neuronal ceroid lipofuscinoses. SCIENCE ADVANCES 2022; 8:eabm5578. [PMID: 35921411 PMCID: PMC9348797 DOI: 10.1126/sciadv.abm5578] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 06/17/2022] [Indexed: 06/15/2023]
Abstract
Lysosomes are central organelles for cellular degradation and energy metabolism. Neuronal ceroid lipofuscinoses (NCLs) are a group of the most common neurodegenerative lysosomal storage disorders characterized by intracellular accumulation of ceroid in neurons. Mutations in KCTD7, a gene encoding an adaptor of the CUL3-RING E3 ubiquitin ligase (CRL3) complex, are categorized as a unique NCL subtype. However, the underlying mechanisms remain elusive. Here, we report various lysosomal and autophagic defects in KCTD7-deficient cells. Mechanistically, the CRL3-KCTD7 complex degrades CLN5, whereas patient-derived KCTD7 mutations disrupt the interaction between KCTD7-CUL3 or KCTD7-CLN5 and ultimately lead to excessive accumulation of CLN5. The accumulated CLN5 disrupts the interaction between CLN6/8 and lysosomal enzymes at the endoplasmic reticulum (ER), subsequently impairing ER-to-Golgi trafficking of lysosomal enzymes. Our findings reveal previously unrecognized roles of KCTD7-mediated CLN5 proteolysis in lysosomal homeostasis and demonstrate that KCTD7 and CLN5 are biochemically linked and function in a common neurodegenerative pathway.
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Affiliation(s)
- Yalan Wang
- Obstetrics and Gynecology Hospital, NHC Key Laboratory of Reproduction Regulation, Shanghai Institute of Planned Parenthood Research, State Key Laboratory of Genetic Engineering, School of Life Sciences, Children’s Hospital, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Institute of Reproduction and Development, Fudan University, Shanghai, China
| | - Xiaotong Cao
- Obstetrics and Gynecology Hospital, NHC Key Laboratory of Reproduction Regulation, Shanghai Institute of Planned Parenthood Research, State Key Laboratory of Genetic Engineering, School of Life Sciences, Children’s Hospital, Fudan University, Shanghai, China
| | - Pei Liu
- Obstetrics and Gynecology Hospital, NHC Key Laboratory of Reproduction Regulation, Shanghai Institute of Planned Parenthood Research, State Key Laboratory of Genetic Engineering, School of Life Sciences, Children’s Hospital, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Institute of Reproduction and Development, Fudan University, Shanghai, China
| | - Weijia Zeng
- Obstetrics and Gynecology Hospital, NHC Key Laboratory of Reproduction Regulation, Shanghai Institute of Planned Parenthood Research, State Key Laboratory of Genetic Engineering, School of Life Sciences, Children’s Hospital, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Institute of Reproduction and Development, Fudan University, Shanghai, China
| | - Rui Peng
- Obstetrics and Gynecology Hospital, NHC Key Laboratory of Reproduction Regulation, Shanghai Institute of Planned Parenthood Research, State Key Laboratory of Genetic Engineering, School of Life Sciences, Children’s Hospital, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Institute of Reproduction and Development, Fudan University, Shanghai, China
| | - Qing Shi
- Obstetrics and Gynecology Hospital, NHC Key Laboratory of Reproduction Regulation, Shanghai Institute of Planned Parenthood Research, State Key Laboratory of Genetic Engineering, School of Life Sciences, Children’s Hospital, Fudan University, Shanghai, China
| | - Kai Feng
- Obstetrics and Gynecology Hospital, NHC Key Laboratory of Reproduction Regulation, Shanghai Institute of Planned Parenthood Research, State Key Laboratory of Genetic Engineering, School of Life Sciences, Children’s Hospital, Fudan University, Shanghai, China
| | - Pingzhao Zhang
- Department of Pathology, School of Basic Medical Sciences, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, China
| | - Huiru Sun
- Obstetrics and Gynecology Hospital, NHC Key Laboratory of Reproduction Regulation, Shanghai Institute of Planned Parenthood Research, State Key Laboratory of Genetic Engineering, School of Life Sciences, Children’s Hospital, Fudan University, Shanghai, China
| | - Chenji Wang
- Obstetrics and Gynecology Hospital, NHC Key Laboratory of Reproduction Regulation, Shanghai Institute of Planned Parenthood Research, State Key Laboratory of Genetic Engineering, School of Life Sciences, Children’s Hospital, Fudan University, Shanghai, China
| | - Hongyan Wang
- Obstetrics and Gynecology Hospital, NHC Key Laboratory of Reproduction Regulation, Shanghai Institute of Planned Parenthood Research, State Key Laboratory of Genetic Engineering, School of Life Sciences, Children’s Hospital, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Institute of Reproduction and Development, Fudan University, Shanghai, China
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13
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Kim WD, Wilson-Smillie MLDM, Thanabalasingam A, Lefrancois S, Cotman SL, Huber RJ. Autophagy in the Neuronal Ceroid Lipofuscinoses (Batten Disease). Front Cell Dev Biol 2022; 10:812728. [PMID: 35252181 PMCID: PMC8888908 DOI: 10.3389/fcell.2022.812728] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 01/24/2022] [Indexed: 12/22/2022] Open
Abstract
The neuronal ceroid lipofuscinoses (NCLs), also referred to as Batten disease, are a family of neurodegenerative diseases that affect all age groups and ethnicities around the globe. At least a dozen NCL subtypes have been identified that are each linked to a mutation in a distinct ceroid lipofuscinosis neuronal (CLN) gene. Mutations in CLN genes cause the accumulation of autofluorescent lipoprotein aggregates, called ceroid lipofuscin, in neurons and other cell types outside the central nervous system. The mechanisms regulating the accumulation of this material are not entirely known. The CLN genes encode cytosolic, lysosomal, and integral membrane proteins that are associated with a variety of cellular processes, and accumulated evidence suggests they participate in shared or convergent biological pathways. Research across a variety of non-mammalian and mammalian model systems clearly supports an effect of CLN gene mutations on autophagy, suggesting that autophagy plays an essential role in the development and progression of the NCLs. In this review, we summarize research linking the autophagy pathway to the NCLs to guide future work that further elucidates the contribution of altered autophagy to NCL pathology.
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Affiliation(s)
- William D. Kim
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON, Canada
| | | | - Aruban Thanabalasingam
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON, Canada
| | - Stephane Lefrancois
- Centre Armand-Frappier Santé Biotechnologie, Institut National de La Recherche Scientifique, Laval, QC, Canada
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada
- Centre D'Excellence en Recherche sur Les Maladies Orphelines–Fondation Courtois (CERMO-FC), Université Du Québec à Montréal (UQAM), Montréal, QC, Canada
| | - Susan L. Cotman
- Department of Neurology, Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, MA, United States
| | - Robert J. Huber
- Department of Biology, Trent University, Peterborough, ON, Canada
- *Correspondence: Robert J. Huber,
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14
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Narayanan DL, Somashekar PH, Majethia P, Shukla A. KCTD7-related progressive myoclonic epilepsy: report of three Indian families and review of literature. Clin Dysmorphol 2022; 31:6-10. [PMID: 34866617 PMCID: PMC8918358 DOI: 10.1097/mcd.0000000000000394] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Epilepsy, progressive myoclonic 3, with or without intracellular inclusions (MIM# 611726) is a rare autosomal recessive condition associated with pathogenic variants in KCTD7, which encodes the BR-C,ttk and bab/pox virus and zinc finger domain-containing KCTD7 protein. We report four individuals from three Indian families presenting with an initial period of normal development, progressive myoclonic seizures followed by neuroregression and an abnormal electroencephalogram. We identified two novel missense variants, c.458G>C p.(Arg153Pro) and c.205C>G p.(Leu69Val) and one known disease-causing variant, c.280C>T p.(Arg94Trp) in KCTD7 by exome sequencing. We review the literature of 67 individuals with variants in KCTD7. Our study expands the molecular spectrum of KCTD7-related progressive myoclonic epilepsy.
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Affiliation(s)
- Dhanya Lakshmi Narayanan
- Department of Medical Genetics, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
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15
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Gardner E, Mole SE. The Genetic Basis of Phenotypic Heterogeneity in the Neuronal Ceroid Lipofuscinoses. Front Neurol 2021; 12:754045. [PMID: 34733232 PMCID: PMC8558747 DOI: 10.3389/fneur.2021.754045] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 09/20/2021] [Indexed: 12/12/2022] Open
Abstract
The neuronal ceroid lipofuscinoses (NCLs) are a group of inherited neurodegenerative disorders that affect children and adults. They share some similar clinical features and the accumulation of autofluorescent storage material. Since the discovery of the first causative genes, more than 530 mutations have been identified across 13 genes in cases diagnosed with NCL. These genes encode a variety of proteins whose functions have not been fully defined; most are lysosomal enzymes, or transmembrane proteins of the lysosome or other organelles. Many mutations in these genes are associated with a typical NCL disease phenotype. However, increasing numbers of variant disease phenotypes are being described, affecting age of onset, severity or progression, and including some distinct clinical phenotypes. This data is collated by the NCL Mutation Database which allows analysis from many perspectives. This article will summarise and interpret current knowledge and understanding of their genetic basis and phenotypic heterogeneity.
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Affiliation(s)
- Emily Gardner
- MRC Laboratory for Molecular Cell Biology and Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Sara E Mole
- MRC Laboratory for Molecular Cell Biology and Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
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16
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Binaafar S, Garshasbi M, Tavasoli AR, Badv RS, Hosseiny SMM, Samanta D, Rabbani B, Mahdieh N. Nonsyndromic Early-Onset Epileptic Encephalopathies: Two Novel KCTD7 Pathogenic Variants and a Literature Review. Dev Neurosci 2021; 43:348-357. [PMID: 34469883 DOI: 10.1159/000519318] [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: 05/29/2021] [Accepted: 08/30/2021] [Indexed: 11/19/2022] Open
Abstract
Early-onset epileptic encephalopathies (EOEE) affect cognitive, sensory, and motor development. Genetic variations are among the identifiable primary causes of these syndromes. However, some patients have been reported to be affected by EOEE without any other clinical symptoms and signs. We study the genotype and phenotype of patients with nonsyndromic early-onset epileptic encephalopathy (NSEOEE) and report 2 novel patients from Iran. A comprehensive search was conducted in PubMed, John Willy, Springer, Elsevier, and Google Scholar databases to collect related information of all the previously reported cases with KCTD7 mutations. Fifty-four patients (from 40 families) were investigated. Using trio-whole-exome sequencing (trio-WES) and Sanger sequencing, the possible genetic causes of the disorder were checked. The probable impacts of the identified variants on the KCTD7 protein structure and function were predicted. This study provided a detailed overview of all published KCTD7 mutations and 2 de novo ones. We identified 2 novel homozygous variants of uncertain significance, c.458 G > A p. Arg153His and c.529C > T (p.Arg177Cys), in KCTD7 (NM_153033.4) (Chr7(GRCh37)). There is a significant wide distribution of the KCTD7 gene causing NSEOEE among different populations. In conclusion, KCTD7 mutations demonstrate a diverse geographical distribution alongside a wide range of ethnicities. This highlights the importance of careful consideration in the WES data analysis. Mutations of this gene may be a common cause of NSEOEE. Also, this study imprints targeted therapeutic opportunities for potassium channelepsies such as KCTD7-related NSEOEE.
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Affiliation(s)
- Sima Binaafar
- Growth and Development Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Masoud Garshasbi
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Ali Reza Tavasoli
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Reza Shervin Badv
- Children's Hospital Center, Pediatric Center of Excellence, Tehran University of Medical Center, Tehran, Iran
| | - Seyyed Mohammad Mahdi Hosseiny
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Debopam Samanta
- Child Neurology Section, Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Bahareh Rabbani
- Growth and Development Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Nejat Mahdieh
- Growth and Development Research Center, Tehran University of Medical Sciences, Tehran, Iran.,Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
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17
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New avenues in molecular genetics for the diagnosis and application of therapeutics to the epilepsies. Epilepsy Behav 2021; 121:106428. [PMID: 31400936 DOI: 10.1016/j.yebeh.2019.07.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 06/14/2019] [Accepted: 07/06/2019] [Indexed: 11/22/2022]
Abstract
Genetic epidemiology studies have shown that most epilepsies involve some genetic cause. In addition, twin studies have helped strengthen the hypothesis that in most patients with epilepsy, a complex inheritance is involved. More recently, with the development of high-density single-nucleotide polymorphism (SNP) microarrays and next-generation sequencing (NGS) technologies, the discovery of genes related to the epilepsies has accelerated tremendously. Especially, the use of whole exome sequencing (WES) has had a considerable impact on the identification of rare genetic variants with large effect sizes, including inherited or de novo mutations in severe forms of childhood epilepsies. The identification of pathogenic variants in patients with these childhood epilepsies provides many benefits for patients and families, such as the confirmation of the genetic nature of the diseases. This process will allow for better genetic counseling, more accurate therapy decisions, and a significant positive emotional impact. However, to study the genetic component of the more common forms of epilepsy, the use of high-density SNP arrays in genome-wide association studies (GWAS) seems to be the strategy of choice. As such, researchers can identify loci containing genetic variants associated with the common forms of epilepsy. The knowledge generated over the past two decades about the effects of the mutations that cause the monogenic epilepsy is tremendous; however, the scientific community is just starting to apply this information in order to generate better target treatments.
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18
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Singh RB, Gupta P, Kartik A, Farooqui N, Singhal S, Shergill S, Singh KP, Agarwal A. Ocular Manifestations of Neuronal Ceroid Lipofuscinoses. Semin Ophthalmol 2021; 36:582-595. [PMID: 34106804 DOI: 10.1080/08820538.2021.1936571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Neuronal ceroid lipofuscinoses (NCLs) are a group of rare neurodegenerative storage disorders associated with devastating visual prognosis, with an incidence of 1/1,000,000 in the United States and comparatively higher incidence in European countries. The pathophysiological mechanisms causing NCLs occur due to enzymatic or transmembrane defects in various sub-cellular organelles including lysosomes, endoplasmic reticulum, and cytoplasmic vesicles. NCLs are categorized into different types depending upon the underlying cause i.e., soluble lysosomal enzyme deficiencies or non-enzymatic deficiencies (functions of identified proteins), which are sub-divided based on an axial classification system. In this review, we have evaluated the current evidence in the literature and reported the incidence rates, underlying mechanisms and currently available management protocols for these rare set of neuroophthalmological disorders. Additionally, we also highlighted the potential therapies under development that can expand the treatment of these rare disorders beyond symptomatic relief.
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Affiliation(s)
- Rohan Bir Singh
- Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.,Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands
| | - Prakash Gupta
- Department of Internal Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Akash Kartik
- Department of Hepatobiliary and Pancreatic Surgery, Mayo Clinic, Rochester, MN, USA
| | - Naba Farooqui
- Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Sachi Singhal
- Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA
| | - Sukhman Shergill
- Department of Anesthesiology, Yale-New Haven Hospital, New Haven, CT, USA
| | - Kanwar Partap Singh
- Department of Ophthalmology, Dayanand Medical College & Hospital, Ludhiana, India
| | - Aniruddha Agarwal
- Eye Institute, Cleveland Clinic Abu Dhabi, Abu Dhabi, United Arab Emirates
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19
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Burke EA, Sturgeon M, Zastrow DB, Fernandez L, Prybol C, Marwaha S, Frothingham EP, Ward PA, Eng CM, Fresard L, Montgomery SB, Enns GM, Fisher PG, Wolfe LA, Harding B, Carrington B, Bishop K, Sood R, Huang Y, Elkahloun A, Toro C, Bassuk AG, Wheeler MT, Markello TC, Gahl WA, Malicdan MCV. Compound heterozygous KCTD7 variants in progressive myoclonus epilepsy. J Neurogenet 2021; 35:74-83. [PMID: 33970744 DOI: 10.1080/01677063.2021.1892095] [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] [Indexed: 10/21/2022]
Abstract
KCTD7 is a member of the potassium channel tetramerization domain-containing protein family and has been associated with progressive myoclonic epilepsy (PME), characterized by myoclonus, epilepsy, and neurological deterioration. Here we report four affected individuals from two unrelated families in which we identified KCTD7 compound heterozygous single nucleotide variants through exome sequencing. RNAseq was used to detect a non-annotated splicing junction created by a synonymous variant in the second family. Whole-cell patch-clamp analysis of neuroblastoma cells overexpressing the patients' variant alleles demonstrated aberrant potassium regulation. While all four patients experienced many of the common clinical features of PME, they also showed variable phenotypes not previously reported, including dysautonomia, brain pathology findings including a significantly reduced thalamus, and the lack of myoclonic seizures. To gain further insight into the pathogenesis of the disorder, zinc finger nucleases were used to generate kctd7 knockout zebrafish. Kctd7 homozygous mutants showed global dysregulation of gene expression and increased transcription of c-fos, which has previously been correlated with seizure activity in animal models. Together these findings expand the known phenotypic spectrum of KCTD7-associated PME, report a new animal model for future studies, and contribute valuable insights into the disease.
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Affiliation(s)
- Elizabeth A Burke
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH and National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | - Morgan Sturgeon
- Department of Pediatrics, University of Iowa, Iowa City, IA, USA
| | - Diane B Zastrow
- Center for Undiagnosed Diseases, Stanford University School of Medicine, Stanford, CA, USA
| | - Liliana Fernandez
- Center for Undiagnosed Diseases, Stanford University School of Medicine, Stanford, CA, USA
| | - Cameron Prybol
- Center for Undiagnosed Diseases, Stanford University School of Medicine, Stanford, CA, USA
| | - Shruti Marwaha
- Center for Undiagnosed Diseases, Stanford University School of Medicine, Stanford, CA, USA
| | | | - Patricia A Ward
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Christine M Eng
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Laure Fresard
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
| | - Stephen B Montgomery
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA.,Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Gregory M Enns
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - Paul G Fisher
- Center for Undiagnosed Diseases, Stanford University School of Medicine, Stanford, CA, USA.,Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA.,Department of Neurology, Stanford University School of Medicine, Stanford, CA, USA
| | - Lynne A Wolfe
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH and National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | - Brian Harding
- Departments of Pathology and Lab Medicine (Neuropathology), Children's Hospital of Philadelphia and the Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Blake Carrington
- Zebrafish Core, Translational and Functional Genomics Branch, National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | - Kevin Bishop
- Zebrafish Core, Translational and Functional Genomics Branch, National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | - Raman Sood
- Zebrafish Core, Translational and Functional Genomics Branch, National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | - Yan Huang
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH and National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | - Abdel Elkahloun
- Microarray Core, Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | - Camilo Toro
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH and National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | | | - Matthew T Wheeler
- Center for Undiagnosed Diseases, Stanford University School of Medicine, Stanford, CA, USA
| | - Thomas C Markello
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH and National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | - William A Gahl
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH and National Human Genome Research Institute, NIH, Bethesda, MD, USA.,Medical Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | - May Christine V Malicdan
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, NIH and National Human Genome Research Institute, NIH, Bethesda, MD, USA
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20
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Dudipala SC, M P, Chennadi AK. A Novel Mutation in KCDT7 Gene in an Indian Girl With Progressive Myoclonus Epilepsy. Cureus 2021; 13:e13447. [PMID: 33767931 PMCID: PMC7982382 DOI: 10.7759/cureus.13447] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The progressive myoclonus epilepsy (PME) is a rare group of clinically and genetically heterogeneous disorders characterized by myoclonus, drug refractory epilepsy, and neurological deterioration. Here, we report a three-year-old female patient with neuroregression after a period of normal development and uncontrollable myoclonic seizures, which fulfill the criteria of PME. Next-generation sequencing revealed a novel homozygous mutation of variant c.173G>C in exon 2 of the KCDT7 (potassium channel tetramerization domain containing protein 7) gene that was compatible with the diagnosis of progressive myoclonic epilepsy 3 (PME3) with or without intracellular inclusions. This is a rare report of KCTD7 mutations causing PME in the Indian population. Our findings supported the important role of KCTD7 in PME and broadened the mutation spectrum.
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Affiliation(s)
- Sai Chandar Dudipala
- Pediatric Neurology, Star Women & Children Hospital, Karimnagar, IND.,Pediatrics, Prathima Institute of Medical Sciences, Karimnagar, IND
| | - Prashanthi M
- Pediatrics, Prathima Institute of Medical Sciences, Karimnagar, IND
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21
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Rossi M, van der Veen S, Merello M, Tijssen MAJ, van de Warrenburg B. Myoclonus-Ataxia Syndromes: A Diagnostic Approach. Mov Disord Clin Pract 2020; 8:9-24. [PMID: 33426154 DOI: 10.1002/mdc3.13106] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 09/30/2020] [Accepted: 10/14/2020] [Indexed: 12/30/2022] Open
Abstract
Background A myriad of disorders combine myoclonus and ataxia. Most causes are genetic and an increasing number of genes are being associated with myoclonus-ataxia syndromes (MAS), due to recent advances in genetic techniques. A proper etiologic diagnosis of MAS is clinically relevant, given the consequences for genetic counseling, treatment, and prognosis. Objectives To review the causes of MAS and to propose a diagnostic algorithm. Methods A comprehensive and structured literature search following PRISMA criteria was conducted to identify those disorders that may combine myoclonus with ataxia. Results A total of 135 causes of combined myoclonus and ataxia were identified, of which 30 were charted as the main causes of MAS. These include four acquired entities: opsoclonus-myoclonus-ataxia syndrome, celiac disease, multiple system atrophy, and sporadic prion diseases. The distinction between progressive myoclonus epilepsy and progressive myoclonus ataxia poses one of the main diagnostic dilemmas. Conclusions Diagnostic algorithms for pediatric and adult patients, based on clinical manifestations including epilepsy, are proposed to guide the differential diagnosis and corresponding work-up of the most important and frequent causes of MAS. A list of genes associated with MAS to guide genetic testing strategies is provided. Priority should be given to diagnose or exclude acquired or treatable disorders.
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Affiliation(s)
- Malco Rossi
- Movement Disorders Section Neuroscience Department Buenos Aires Argentina.,Argentine National Scientific and Technological Research Council (CONICET) Buenos Aires Argentina
| | - Sterre van der Veen
- Pontificia Universidad Católica Argentina (UCA) Buenos Aires Argentina.,Department of Neurology University of Groningen, University Medical Center Groningen Groningen The Netherlands
| | - Marcelo Merello
- Movement Disorders Section Neuroscience Department Buenos Aires Argentina.,Argentine National Scientific and Technological Research Council (CONICET) Buenos Aires Argentina.,Pontificia Universidad Católica Argentina (UCA) Buenos Aires Argentina
| | - Marina A J Tijssen
- Department of Neurology University of Groningen, University Medical Center Groningen Groningen The Netherlands.,Expertise Center Movement Disorders Groningen University Medical Center Groningen (UMCG) Groningen The Netherlands
| | - Bart van de Warrenburg
- Department of Neurology, Donders Institute for Brain, Cognition & Behaviour Radboud University Medical Center Nijmegen The Netherlands
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22
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Teixeira V, Maciel P, Costa V. Leading the way in the nervous system: Lipid Droplets as new players in health and disease. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1866:158820. [PMID: 33010453 DOI: 10.1016/j.bbalip.2020.158820] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 09/01/2020] [Accepted: 09/21/2020] [Indexed: 12/28/2022]
Abstract
Lipid droplets (LDs) are ubiquitous fat storage organelles composed of a neutral lipid core, comprising triacylglycerols (TAG) and sterol esters (SEs), surrounded by a phospholipid monolayer membrane with several decorating proteins. Recently, LD biology has come to the foreground of research due to their importance for energy homeostasis and cellular stress response. As aberrant LD accumulation and lipid depletion are hallmarks of numerous diseases, addressing LD biogenesis and turnover provides a new framework for understanding disease-related mechanisms. Here we discuss the potential role of LDs in neurodegeneration, while making some predictions on how LD imbalance can contribute to pathophysiology in the brain.
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Affiliation(s)
- Vitor Teixeira
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade of Porto, Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.
| | - Patrícia Maciel
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Vítor Costa
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade of Porto, Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal; ICBAS, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
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23
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Butz ES, Chandrachud U, Mole SE, Cotman SL. Moving towards a new era of genomics in the neuronal ceroid lipofuscinoses. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165571. [DOI: 10.1016/j.bbadis.2019.165571] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 10/12/2019] [Accepted: 10/14/2019] [Indexed: 12/15/2022]
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24
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Bauwens M, Storch S, Weisschuh N, Ceuterick‐de Groote C, De Rycke R, Guillemyn B, De Jaegere S, Coppieters F, Van Coster R, Leroy BP, De Baere E. Functional characterization of novel MFSD8 pathogenic variants anticipates neurological involvement in juvenile isolated maculopathy. Clin Genet 2020; 97:426-436. [PMID: 31721179 PMCID: PMC7064892 DOI: 10.1111/cge.13673] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 10/30/2019] [Accepted: 11/01/2019] [Indexed: 12/22/2022]
Abstract
Biallelic MFSD8 variants are an established cause of severe late-infantile subtype of neuronal ceroid lipofuscinosis (v-LINCL), a severe lysosomal storage disorder, but have also been associated with nonsyndromic adult-onset maculopathy. Here, we functionally characterized two novel MFSD8 variants found in a child with juvenile isolated maculopathy, in order to establish a refined prognosis. ABCA4 locus resequencing was followed by the analysis of other inherited retinal disease genes by whole exome sequencing (WES). Minigene assays and cDNA sequencing were used to assess the effect of a novel MFSD8 splice variant. MFSD8 expression was quantified with qPCR and overexpression studies were analyzed by immunoblotting. Transmission electron microscopy (TEM) was performed on a skin biopsy and ophthalmological and neurological re-examinations were conducted. WES revealed two novel MFSD8 variants: c.[590del];[439+3A>C] p.[Gly197Valfs*2];[Ile67Glufs*3]. Characterization of the c.439+3A>C variant via splice assays showed exon-skipping (p.Ile67Glufs*3), while overexpression studies of the corresponding protein indicated expression of a truncated polypeptide. In addition, a significantly reduced MFSD8 RNA expression was noted in patient's lymphocytes. TEM of a skin biopsy revealed typical v-LINCL lipopigment inclusions while neurological imaging of the proband displayed subtle cerebellar atrophy. Functional characterization demonstrated the pathogenicity of two novel MFSD8 variants, found in a child with an initial diagnosis of juvenile isolated maculopathy but likely evolving to v-LINCL with a protracted disease course. Our study allowed a refined neurological prognosis in the proband and expands the natural history of MFSD8-associated disease.
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Affiliation(s)
| | - Stephan Storch
- Department of Biochemistry, Children's HospitalUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Nicole Weisschuh
- Molecular Genetics Laboratory, Institute for Ophthalmic ResearchUniversity of TuebingenTuebingenGermany
| | | | - Riet De Rycke
- Department of Biomedical Molecular BiologyGhent UniversityGhentBelgium
- VIB‐UGent Center for Inflammation ResearchGhentBelgium
- Ghent University Expertise Centre for Transmission Electron Microscopy and VIB BioImaging CoreGhentBelgium
| | | | - Sarah De Jaegere
- Center for Medical GeneticsGhent University HospitalGhentBelgium
| | | | - Rudy Van Coster
- Department of Pediatrics, Division of Pediatric Neurology and MetabolismGhent University HospitalGhentBelgium
| | - Bart P. Leroy
- Center for Medical GeneticsGhent University HospitalGhentBelgium
- Department of OphthalmologyGhent University and Ghent University HospitalGhentBelgium
- Division of Ophthalmology and Center for Cellular & Molecular TherapeuticsThe Children's Hospital of PhiladelphiaPhiladelphiaPennsylvania
| | - Elfride De Baere
- Center for Medical GeneticsGhent UniversityGhentBelgium
- Center for Medical GeneticsGhent University HospitalGhentBelgium
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25
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Lugo M, Wong ZC, Billington CJ, Parrish PCR, Muldoon G, Liu D, Pober BR, Kozel BA. Social, neurodevelopmental, endocrine, and head size differences associated with atypical deletions in Williams-Beuren syndrome. Am J Med Genet A 2020; 182:1008-1020. [PMID: 32077592 DOI: 10.1002/ajmg.a.61522] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 01/22/2020] [Accepted: 01/28/2020] [Indexed: 12/21/2022]
Abstract
Williams-Beuren syndrome (WBS) is a multisystem disorder caused by a hemizygous deletion on 7q11.23 encompassing 26-28 genes. An estimated 2-5% of patients have "atypical" deletions, which extend in the centromeric and/or telomeric direction from the WBS critical region. To elucidate clinical differentiators among these deletion types, we evaluated 10 individuals with atypical deletions in our cohort and 17 individuals with similarly classified deletions previously described in the literature. Larger deletions in either direction often led to more severe developmental delays, while deletions containing MAGI2 were associated with infantile spasms and seizures in patients. In addition, head size was notably smaller in those with centromeric deletions including AUTS2. Because children with atypical deletions were noted to be less socially engaged, we additionally sought to determine how atypical deletions relate to social phenotypes. Using the Social Responsiveness Scale-2, raters scored individuals with atypical deletions as having different social characteristics to those with typical WBS deletions (p = .001), with higher (more impaired) scores for social motivation (p = .005) in the atypical deletion group. In recognizing these distinctions, physicians can better identify patients, including those who may already carry a clinical or FISH WBS diagnosis, who may benefit from additional molecular evaluation, screening, and therapy. In addition to the clinical findings, we note mild endocrine findings distinct from those typically seen in WBS in several patients with telomeric deletions that included POR. Further study in additional telomeric deletion cases will be needed to confirm this observation.
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Affiliation(s)
- Michael Lugo
- Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolina.,Translational Vascular Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Zoë C Wong
- Translational Vascular Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Charles J Billington
- Medical Genetics and Genomic Medicine Training Program, National Human Genetics Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Phoebe C R Parrish
- Translational Vascular Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland.,Department of Genome Sciences, University of Washington, Seattle, Washington
| | - Glennis Muldoon
- Neurodevelopmental and Behavioral Phenotyping Service, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Delong Liu
- Translational Vascular Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Barbara R Pober
- Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts
| | - Beth A Kozel
- Translational Vascular Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland.,Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri
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26
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KCTD15 is overexpressed in human childhood B-cell acute lymphoid leukemia. Sci Rep 2019; 9:20108. [PMID: 31882877 PMCID: PMC6934626 DOI: 10.1038/s41598-019-56701-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 12/11/2019] [Indexed: 12/11/2022] Open
Abstract
Leukemic cells originate from the malignant transformation of undifferentiated myeloid/lymphoid hematopoietic progenitors normally residing in bone marrow. As the precise molecular mechanisms underlying this heterogeneous disease are yet to be disclosed, the identification and the validation of novel actors in leukemia is of extreme importance. Here, we show that KCTD15, a member of the emerging class of KCTD ((K)potassium Channel Tetramerization Domain containing) proteins, is strongly upregulated in patients affected by B-cell type acute lymphoblastic leukemia (B-ALL) and in continuous cell lines (RS4;11, REH, TOM-1, SEM) derived from this form of childhood leukemia. Interestingly, KCTD15 downregulation induces apoptosis and cell death suggesting that it has a role in cellular homeostasis and proliferation. In addition, stimulation of normal lymphocytes with the pokeweed mitogen leads to increased KCTD15 levels in a fashion comparable to those observed in proliferating leukemic cells. In this way, the role of KCTD15 is likely not confined to the B-ALL pathological state and extends to activation and proliferation of normal lymphocytes. Collectively, data here presented indicate that KCTD15 is an important and hitherto unidentified player in childhood lymphoid leukemia, and its study could open a new scenario for the identification of altered and still unknown molecular pathways in leukemia.
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27
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Mastrangelo M, Sartori S, Simonati A, Brinciotti M, Moro F, Nosadini M, Pezzini F, Doccini S, Santorelli FM, Leuzzi V. Progressive myoclonus epilepsy and ceroidolipofuscinosis 14: The multifaceted phenotypic spectrum of KCTD7-related disorders. Eur J Med Genet 2019; 62:103591. [DOI: 10.1016/j.ejmg.2018.11.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 09/28/2018] [Accepted: 11/22/2018] [Indexed: 11/27/2022]
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28
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Beaudin M, Matilla-Dueñas A, Soong BW, Pedroso JL, Barsottini OG, Mitoma H, Tsuji S, Schmahmann JD, Manto M, Rouleau GA, Klein C, Dupre N. The Classification of Autosomal Recessive Cerebellar Ataxias: a Consensus Statement from the Society for Research on the Cerebellum and Ataxias Task Force. CEREBELLUM (LONDON, ENGLAND) 2019; 18:1098-1125. [PMID: 31267374 PMCID: PMC6867988 DOI: 10.1007/s12311-019-01052-2] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
There is currently no accepted classification of autosomal recessive cerebellar ataxias, a group of disorders characterized by important genetic heterogeneity and complex phenotypes. The objective of this task force was to build a consensus on the classification of autosomal recessive ataxias in order to develop a general approach to a patient presenting with ataxia, organize disorders according to clinical presentation, and define this field of research by identifying common pathogenic molecular mechanisms in these disorders. The work of this task force was based on a previously published systematic scoping review of the literature that identified autosomal recessive disorders characterized primarily by cerebellar motor dysfunction and cerebellar degeneration. The task force regrouped 12 international ataxia experts who decided on general orientation and specific issues. We identified 59 disorders that are classified as primary autosomal recessive cerebellar ataxias. For each of these disorders, we present geographical and ethnical specificities along with distinctive clinical and imagery features. These primary recessive ataxias were organized in a clinical and a pathophysiological classification, and we present a general clinical approach to the patient presenting with ataxia. We also identified a list of 48 complex multisystem disorders that are associated with ataxia and should be included in the differential diagnosis of autosomal recessive ataxias. This classification is the result of a consensus among a panel of international experts, and it promotes a unified understanding of autosomal recessive cerebellar disorders for clinicians and researchers.
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Affiliation(s)
- Marie Beaudin
- Axe Neurosciences, CHU de Québec-Université Laval, Québec, QC, Canada
- Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, QC, Canada
| | - Antoni Matilla-Dueñas
- Department of Neuroscience, Health Sciences Research Institute Germans Trias i Pujol (IGTP), Universitat Autònoma de Barcelona, Badalona, Barcelona, Spain
| | - Bing-Weng Soong
- Department of Neurology, Shuang Ho Hospital and Taipei Neuroscience Institute, Taipei Medical University, Taipei, Taiwan, Republic of China
- National Yang-Ming University School of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China
| | - Jose Luiz Pedroso
- Ataxia Unit, Department of Neurology, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Orlando G Barsottini
- Ataxia Unit, Department of Neurology, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Hiroshi Mitoma
- Medical Education Promotion Center, Tokyo Medical University, Tokyo, Japan
| | - Shoji Tsuji
- The University of Tokyo, Tokyo, Japan
- International University of Health and Welfare, Chiba, Japan
| | - Jeremy D Schmahmann
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Mario Manto
- Service de Neurologie, Médiathèque Jean Jacquy, CHU-Charleroi, 6000, Charleroi, Belgium
- Service des Neurosciences, UMons, Mons, Belgium
| | | | | | - Nicolas Dupre
- Axe Neurosciences, CHU de Québec-Université Laval, Québec, QC, Canada.
- Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, QC, Canada.
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Huber RJ, Hughes SM, Liu W, Morgan A, Tuxworth RI, Russell C. The contribution of multicellular model organisms to neuronal ceroid lipofuscinosis research. Biochim Biophys Acta Mol Basis Dis 2019; 1866:165614. [PMID: 31783156 DOI: 10.1016/j.bbadis.2019.165614] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 11/14/2019] [Accepted: 11/15/2019] [Indexed: 02/07/2023]
Abstract
The NCLs (neuronal ceroid lipofuscinosis) are forms of neurodegenerative disease that affect people of all ages and ethnicities but are most prevalent in children. Commonly known as Batten disease, this debilitating neurological disorder is comprised of 13 different subtypes that are categorized based on the particular gene that is mutated (CLN1-8, CLN10-14). The pathological mechanisms underlying the NCLs are not well understood due to our poor understanding of the functions of NCL proteins. Only one specific treatment (enzyme replacement therapy) is approved, which is for the treating the brain in CLN2 disease. Hence there remains a desperate need for further research into disease-modifying treatments. In this review, we present and evaluate the genes, proteins and studies performed in the social amoeba, nematode, fruit fly, zebrafish, mouse and large animals pertinent to NCL. In particular, we highlight the use of multicellular model organisms to study NCL protein function, pathology and pathomechanisms. Their use in testing novel therapeutic approaches is also presented. With this information, we highlight how future research in these systems may be able to provide new insight into NCL protein functions in human cells and aid in the development of new therapies.
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Affiliation(s)
- Robert J Huber
- Department of Biology, Trent University, Peterborough, Ontario K9L 0G2, Canada
| | - Stephanie M Hughes
- Department of Biochemistry, School of Biomedical Sciences, Brain Health Research Centre and Genetics Otago, University of Otago, Dunedin, New Zealand
| | - Wenfei Liu
- School of Pharmacy, University College London, London, WC1N 1AX, UK
| | - Alan Morgan
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown St., Liverpool L69 3BX, UK
| | - Richard I Tuxworth
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Claire Russell
- Dept. Comparative Biomedical Sciences, Royal Veterinary College, Royal College Street, London NW1 0TU, UK.
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30
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Menchini RJ, Chaudhry FA. Multifaceted regulation of the system A transporter Slc38a2 suggests nanoscale regulation of amino acid metabolism and cellular signaling. Neuropharmacology 2019; 161:107789. [PMID: 31574264 DOI: 10.1016/j.neuropharm.2019.107789] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 09/16/2019] [Accepted: 09/20/2019] [Indexed: 02/07/2023]
Abstract
Amino acids are essential for cellular protein synthesis, growth, metabolism, signaling and in stress responses. Cell plasma membranes harbor specialized transporters accumulating amino acids to support a variety of cellular biochemical pathways. Several transporters for neutral amino acids have been characterized. However, Slc38a2 (also known as SA1, SAT2, ATA2, SNAT2) representing the classical transport system A activity stands in a unique position: Being a secondarily active transporter energized by the electrochemical gradient of Na+, it creates steep concentration gradients for amino acids such as glutamine: this may subsequently drive the accumulation of additional neutral amino acids through exchange via transport systems ASC and L. Slc38a2 is ubiquitously expressed, yet in a cell-specific manner. In this review, we show that Slc38a2 is regulated at the transcriptional and translational levels as well as by ions and proteins through direct interactions. We describe how Slc38a2 senses amino acid availability and passes this onto intracellular signaling pathways and how it regulates protein synthesis, cellular proliferation and apoptosis through the mechanistic (mammalian) target of rapamycin (mTOR) and general control nonderepressible 2 (GCN2) pathways. Furthermore, we review how this extensively regulated transporter contributes to cellular osmoadaptation and how it is regulated by endoplasmic reticulum stress and various hormonal stimuli to promote cellular metabolism, cellular signaling and cell survival. This article is part of the issue entitled 'Special Issue on Neurotransmitter Transporters'.
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Affiliation(s)
| | - Farrukh Abbas Chaudhry
- Department of Molecular Medicine, University of Oslo, Oslo, Norway; Department of Plastic and Reconstructive Surgery, Oslo University Hospital, Oslo, Norway
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31
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Smaldone G, Balasco N, Pirone L, Caruso D, Di Gaetano S, Pedone EM, Vitagliano L. Molecular basis of the scalp-ear-nipple syndrome unraveled by the characterization of disease-causing KCTD1 mutants. Sci Rep 2019; 9:10519. [PMID: 31324836 PMCID: PMC6642198 DOI: 10.1038/s41598-019-46911-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 07/05/2019] [Indexed: 12/11/2022] Open
Abstract
The scalp-ear-nipple (SEN) syndrome is an autosomal-dominant disorder characterized by cutis aplasia of the scalp and malformations of breast, external ears, digits, and nails. Genetic analyses have shown that the disease is caused by missense mutations of the KCTD1 protein, although the functional/structural basis of SEN insurgence is hitherto unknown. With the aim of unravelling the molecular basis of the SEN syndrome associated with KCTD1 mutations we here expressed and characterized several disease causing mutants. A preliminary dissection of the protein provides insights into the role that individual domains play in KCTD1 stability. The characterization of SEN-causing mutants indicates that, although the mutation sites are located in distant regions of the BTB domain or of the pre-BTB region, all of them are unable to interact with the transcription factor AP-2α, a well-known KCTD1 biological partner. Notably, all mutations, including the one located in the pre-BTB region, produce a significant destabilization of the protein. The structural role of the pre-BTB region in KCTD1 and other proteins of the family is corroborated by its sequence conservation in orthologs and paralogs. Interestingly, SEN-causing mutations also favor the tendency of KCTD1 to adopt structural states that are characterized by the ability to bind the β-amyloid fluorescent dye thioflavin T. The formation of aggregation-prone species may have important implications for the disease etiology. Collectively, these findings provide an intriguing picture of the functional and structural alterations induced by KCTD1 mutations that ultimately lead to disease.
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Affiliation(s)
| | - Nicole Balasco
- Institute of Biostructures and Bioimaging, CNR, Via Mezzocannone 16, 80134, Napoli, Italy
| | - Luciano Pirone
- Institute of Biostructures and Bioimaging, CNR, Via Mezzocannone 16, 80134, Napoli, Italy
| | - Daniela Caruso
- Institute of Biostructures and Bioimaging, CNR, Via Mezzocannone 16, 80134, Napoli, Italy.,Università degli Studi della Campania "Luigi Vanvitelli", Viale Abramo Lincoln 5, 81100, Caserta, Italy
| | - Sonia Di Gaetano
- Institute of Biostructures and Bioimaging, CNR, Via Mezzocannone 16, 80134, Napoli, Italy
| | - Emilia Maria Pedone
- Institute of Biostructures and Bioimaging, CNR, Via Mezzocannone 16, 80134, Napoli, Italy
| | - Luigi Vitagliano
- Institute of Biostructures and Bioimaging, CNR, Via Mezzocannone 16, 80134, Napoli, Italy.
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32
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Teng X, Aouacheria A, Lionnard L, Metz KA, Soane L, Kamiya A, Hardwick JM. KCTD: A new gene family involved in neurodevelopmental and neuropsychiatric disorders. CNS Neurosci Ther 2019; 25:887-902. [PMID: 31197948 PMCID: PMC6566181 DOI: 10.1111/cns.13156] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 05/02/2019] [Accepted: 05/13/2019] [Indexed: 12/12/2022] Open
Abstract
The underlying molecular basis for neurodevelopmental or neuropsychiatric disorders is not known. In contrast, mechanistic understanding of other brain disorders including neurodegeneration has advanced considerably. Yet, these do not approach the knowledge accrued for many cancers with precision therapeutics acting on well-characterized targets. Although the identification of genes responsible for neurodevelopmental and neuropsychiatric disorders remains a major obstacle, the few causally associated genes are ripe for discovery by focusing efforts to dissect their mechanisms. Here, we make a case for delving into mechanisms of the poorly characterized human KCTD gene family. Varying levels of evidence support their roles in neurocognitive disorders (KCTD3), neurodevelopmental disease (KCTD7), bipolar disorder (KCTD12), autism and schizophrenia (KCTD13), movement disorders (KCTD17), cancer (KCTD11), and obesity (KCTD15). Collective knowledge about these genes adds enhanced value, and critical insights into potential disease mechanisms have come from unexpected sources. Translation of basic research on the KCTD-related yeast protein Whi2 has revealed roles in nutrient signaling to mTORC1 (KCTD11) and an autophagy-lysosome pathway affecting mitochondria (KCTD7). Recent biochemical and structure-based studies (KCTD12, KCTD13, KCTD16) reveal mechanisms of regulating membrane channel activities through modulation of distinct GTPases. We explore how these seemingly varied functions may be disease related.
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Affiliation(s)
- Xinchen Teng
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical SciencesSoochow UniversitySuzhouChina
- W. Harry Feinstone Department of Molecular Microbiology and ImmunologyJohns Hopkins University Bloomberg School of Public HealthBaltimoreMaryland
| | - Abdel Aouacheria
- ISEM, Institut des Sciences de l'Evolution de Montpellier, CNRS, EPHE, IRDUniversité de MontpellierMontpellierFrance
| | - Loïc Lionnard
- ISEM, Institut des Sciences de l'Evolution de Montpellier, CNRS, EPHE, IRDUniversité de MontpellierMontpellierFrance
| | - Kyle A. Metz
- W. Harry Feinstone Department of Molecular Microbiology and ImmunologyJohns Hopkins University Bloomberg School of Public HealthBaltimoreMaryland
- Present address:
Feinberg School of MedicineNorthwestern UniversityChicagoUSA
| | - Lucian Soane
- W. Harry Feinstone Department of Molecular Microbiology and ImmunologyJohns Hopkins University Bloomberg School of Public HealthBaltimoreMaryland
| | - Atsushi Kamiya
- Department of Psychiatry and Behavioral SciencesJohns Hopkins School of MedicineBaltimoreMaryland
| | - J. Marie Hardwick
- W. Harry Feinstone Department of Molecular Microbiology and ImmunologyJohns Hopkins University Bloomberg School of Public HealthBaltimoreMaryland
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Alevy J, Burger CA, Albrecht NE, Jiang D, Samuel MA. Progressive myoclonic epilepsy-associated gene Kctd7 regulates retinal neurovascular patterning and function. Neurochem Int 2019; 129:104486. [PMID: 31175897 DOI: 10.1016/j.neuint.2019.104486] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 06/04/2019] [Accepted: 06/05/2019] [Indexed: 12/28/2022]
Abstract
Neuron function relies on and instructs the development and precise organization of neurovascular units that in turn support circuit activity. However, our understanding of the molecular cues that regulate this relationship remains sparse. Using a high-throughput screening pipeline, we recently identified several new regulators of vascular patterning. Among these was the potassium channel tetramerization domain-containing protein 7 (KCTD7). Mutations in KCTD7 are associated with progressive myoclonic epilepsy, but how KCTD7 regulates neural development and function remains poorly understood. To begin to identify such mechanisms, we focus on mouse retina, a tractable part of the central nervous system that contains precisely ordered neuron subtypes supported by a trilaminar vascular network. We find that deletion of Kctd7 induces defective patterning of the adult retina vascular network, resulting in increased branching, vessel length, and lacunarity. These alterations reflect early and specific defects in vessel development, as emergence of the superficial and deep vascular layers were delayed. These defects are likely due to a role for Kctd7 in inner retina neurons. Kctd7 is absent from vessels but present in neurons in the inner retina, and its deletion resulted in a corresponding increase in the number of bipolar cells in development and increased vessel branching in adults. These alterations were accompanied by retinal function deficits. Together, these data suggest that neuronal Kctd7 drives growth and patterning of the vasculature and that neurovascular interactions may participate in the pathogenesis of KCTD7-related human diseases.
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Affiliation(s)
- Jonathan Alevy
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA; Huffington Center on Aging, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Courtney A Burger
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA; Huffington Center on Aging, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Nicholas E Albrecht
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA; Huffington Center on Aging, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Danye Jiang
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA; Huffington Center on Aging, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Melanie A Samuel
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA; Huffington Center on Aging, Baylor College of Medicine, Houston, TX, 77030, USA.
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34
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Exome sequencing identifies compound heterozygous KCTD7 mutations in a girl with progressivemyoclonus epilepsy. Clin Chim Acta 2019; 493:87-91. [DOI: 10.1016/j.cca.2019.02.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 02/13/2019] [Accepted: 02/27/2019] [Indexed: 12/31/2022]
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35
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Zastrow DB, Kohler JN, Bonner D, Reuter CM, Fernandez L, Grove ME, Fisk DG, Yang Y, Eng CM, Ward PA, Bick D, Worthey EA, Fisher PG, Ashley EA, Bernstein JA, Wheeler MT. A toolkit for genetics providers in follow-up of patients with non-diagnostic exome sequencing. J Genet Couns 2019; 28:213-228. [PMID: 30964584 PMCID: PMC7385984 DOI: 10.1002/jgc4.1119] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 03/01/2019] [Accepted: 03/04/2019] [Indexed: 12/11/2022]
Abstract
There are approximately 7,000 rare diseases affecting 25-30 million Americans, with 80% estimated to have a genetic basis. This presents a challenge for genetics practitioners to determine appropriate testing, make accurate diagnoses, and conduct up-to-date patient management. Exome sequencing (ES) is a comprehensive diagnostic approach, but only 25%-41% of the patients receive a molecular diagnosis. The remaining three-fifths to three-quarters of patients undergoing ES remain undiagnosed. The Stanford Center for Undiagnosed Diseases (CUD), a clinical site of the Undiagnosed Diseases Network, evaluates patients with undiagnosed and rare diseases using a combination of methods including ES. Frequently these patients have non-diagnostic ES results, but strategic follow-up techniques identify diagnoses in a subset. We present techniques used at the CUD that can be adopted by genetics providers in clinical follow-up of cases where ES is non-diagnostic. Solved case examples illustrate different types of non-diagnostic results and the additional techniques that led to a diagnosis. Frequent approaches include segregation analysis, data reanalysis, genome sequencing, additional variant identification, careful phenotype-disease correlation, confirmatory testing, and case matching. We also discuss prioritization of cases for additional analyses.
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Affiliation(s)
- Diane B Zastrow
- Center for Undiagnosed Diseases, Stanford University, Stanford, California
| | - Jennefer N Kohler
- Center for Undiagnosed Diseases, Stanford University, Stanford, California
| | - Devon Bonner
- Center for Undiagnosed Diseases, Stanford University, Stanford, California
| | - Chloe M Reuter
- Center for Undiagnosed Diseases, Stanford University, Stanford, California
| | - Liliana Fernandez
- Center for Undiagnosed Diseases, Stanford University, Stanford, California
| | - Megan E Grove
- Clinical Genomics Program, Stanford Health Care, Stanford, California
| | - Dianna G Fisk
- Clinical Genomics Program, Stanford Health Care, Stanford, California
| | | | | | | | - David Bick
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama
| | | | - Paul G Fisher
- Center for Undiagnosed Diseases, Stanford University, Stanford, California
- Department of Neurology, Stanford University School of Medicine, Stanford, California
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - Euan A Ashley
- Center for Undiagnosed Diseases, Stanford University, Stanford, California
- Clinical Genomics Program, Stanford Health Care, Stanford, California
- Department of Genetics, Stanford University School of Medicine, Stanford, California
- Department of Medicine, Stanford University School of Medicine, Stanford, California
| | - Jonathan A Bernstein
- Center for Undiagnosed Diseases, Stanford University, Stanford, California
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - Matthew T Wheeler
- Center for Undiagnosed Diseases, Stanford University, Stanford, California
- Department of Medicine, Stanford University School of Medicine, Stanford, California
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36
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Mukherjee AB, Appu AP, Sadhukhan T, Casey S, Mondal A, Zhang Z, Bagh MB. Emerging new roles of the lysosome and neuronal ceroid lipofuscinoses. Mol Neurodegener 2019; 14:4. [PMID: 30651094 PMCID: PMC6335712 DOI: 10.1186/s13024-018-0300-6] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 12/04/2018] [Indexed: 12/04/2022] Open
Abstract
Neuronal Ceroid Lipofuscinoses (NCLs), commonly known as Batten disease, constitute a group of the most prevalent neurodegenerative lysosomal storage disorders (LSDs). Mutations in at least 13 different genes (called CLNs) cause various forms of NCLs. Clinically, the NCLs manifest early impairment of vision, progressive decline in cognitive and motor functions, seizures and a shortened lifespan. At the cellular level, all NCLs show intracellular accumulation of autofluorescent material (called ceroid) and progressive neuron loss. Despite intense studies the normal physiological functions of each of the CLN genes remain poorly understood. Consequently, the development of mechanism-based therapeutic strategies remains challenging. Endolysosomal dysfunction contributes to pathogenesis of virtually all LSDs. Studies within the past decade have drastically changed the notion that the lysosomes are merely the terminal degradative organelles. The emerging new roles of the lysosome include its central role in nutrient-dependent signal transduction regulating metabolism and cellular proliferation or quiescence. In this review, we first provide a brief overview of the endolysosomal and autophagic pathways, lysosomal acidification and endosome-lysosome and autophagosome-lysosome fusions. We emphasize the importance of these processes as their dysregulation leads to pathogenesis of many LSDs including the NCLs. We also describe what is currently known about each of the 13 CLN genes and their products and how understanding the emerging new roles of the lysosome may clarify the underlying pathogenic mechanisms of the NCLs. Finally, we discuss the current and emerging therapeutic strategies for various NCLs.
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Affiliation(s)
- Anil B. Mukherjee
- Section on Developmental Genetics, Program on Endocrinology and Molecular Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, The National Institutes of Health, Bethesda, Maryland 20892-1830 USA
| | - Abhilash P. Appu
- Section on Developmental Genetics, Program on Endocrinology and Molecular Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, The National Institutes of Health, Bethesda, Maryland 20892-1830 USA
| | - Tamal Sadhukhan
- Section on Developmental Genetics, Program on Endocrinology and Molecular Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, The National Institutes of Health, Bethesda, Maryland 20892-1830 USA
| | - Sydney Casey
- Section on Developmental Genetics, Program on Endocrinology and Molecular Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, The National Institutes of Health, Bethesda, Maryland 20892-1830 USA
| | - Avisek Mondal
- Section on Developmental Genetics, Program on Endocrinology and Molecular Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, The National Institutes of Health, Bethesda, Maryland 20892-1830 USA
| | - Zhongjian Zhang
- Section on Developmental Genetics, Program on Endocrinology and Molecular Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, The National Institutes of Health, Bethesda, Maryland 20892-1830 USA
- Present address: Institute of Psychiatry and Neuroscience, Xinxiang Medical University, Xinxiang, 453003 Henan China
| | - Maria B. Bagh
- Section on Developmental Genetics, Program on Endocrinology and Molecular Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, The National Institutes of Health, Bethesda, Maryland 20892-1830 USA
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37
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Teng X, Yau E, Sing C, Hardwick JM. Whi2 signals low leucine availability to halt yeast growth and cell death. FEMS Yeast Res 2018; 18:5083179. [PMID: 30165592 PMCID: PMC6149368 DOI: 10.1093/femsyr/foy095] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 08/26/2018] [Indexed: 12/16/2022] Open
Abstract
Cells are exquisitely tuned to environmental ques. Amino acid availability is rapidly sensed, allowing cells to adjust molecular processes and implement short or long-term metabolic shifts accordingly. How levels of most individual amino acids may be sensed and subsequently signaled to inform cells of their nutrient status is largely unknown. We made the unexpected observation that small changes in the levels of specific amino acids can have a profound effect on yeast cell growth, leading to the identification of yeast Whi2 as a negative regulator of cell growth in low amino acids. Although Whi2 was originally thought to be fungi-specific, Whi2 appears to share a conserved structural domain found in a family of 25 largely uncharacterized human genes encoding the KCTD (potassium channel tetramerization domain) protein family. Insights gained from yeast Whi2 are likely to be revealing about human KCTDs, many of which have been implicated or demonstrated to cause disease when mutated. Here we report new evidence that Whi2 responds to specific amino acids in the medium, particularly low leucine levels. We also discuss the known pathways of amino acid signaling and potential points of regulation by Whi2 in nutrient signaling in yeast and mammals.
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Affiliation(s)
- Xinchen Teng
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205-2103, USA
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, 215123 Suzhou, Jiangsu Province, People's Republic of China
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2103, USA
| | - Eric Yau
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205-2103, USA
| | - Cierra Sing
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205-2103, USA
| | - J Marie Hardwick
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205-2103, USA
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2103, USA
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38
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Metz KA, Teng X, Coppens I, Lamb HM, Wagner BE, Rosenfeld JA, Chen X, Zhang Y, Kim HJ, Meadow ME, Wang TS, Haberlandt ED, Anderson GW, Leshinsky-Silver E, Bi W, Markello TC, Pratt M, Makhseed N, Garnica A, Danylchuk NR, Burrow TA, Jayakar P, McKnight D, Agadi S, Gbedawo H, Stanley C, Alber M, Prehl I, Peariso K, Ong MT, Mordekar SR, Parker MJ, Crooks D, Agrawal PB, Berry GT, Loddenkemper T, Yang Y, Maegawa GHB, Aouacheria A, Markle JG, Wohlschlegel JA, Hartman AL, Hardwick JM. KCTD7 deficiency defines a distinct neurodegenerative disorder with a conserved autophagy-lysosome defect. Ann Neurol 2018; 84:766-780. [PMID: 30295347 DOI: 10.1002/ana.25351] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 08/27/2018] [Accepted: 09/23/2018] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Several small case series identified KCTD7 mutations in patients with a rare autosomal recessive disorder designated progressive myoclonic epilepsy (EPM3) and neuronal ceroid lipofuscinosis (CLN14). Despite the name KCTD (potassium channel tetramerization domain), KCTD protein family members lack predicted channel domains. We sought to translate insight gained from yeast studies to uncover disease mechanisms associated with deficiencies in KCTD7 of unknown function. METHODS Novel KCTD7 variants in new and published patients were assessed for disease causality using genetic analyses, cell-based functional assays of patient fibroblasts and knockout yeast, and electron microscopy of patient samples. RESULTS Patients with KCTD7 mutations can exhibit movement disorders or developmental regression before seizure onset, and are distinguished from similar disorders by an earlier age of onset. Although most published KCTD7 patient variants were excluded from a genome sequence database of normal human variations, most newly identified patient variants are present in this database, potentially challenging disease causality. However, genetic analysis and impaired biochemical interactions with cullin 3 support a causal role for patient KCTD7 variants, suggesting deleterious alleles of KCTD7 and other rare disease variants may be underestimated. Both patient-derived fibroblasts and yeast lacking Whi2 with sequence similarity to KCTD7 have impaired autophagy consistent with brain pathology. INTERPRETATION Biallelic KCTD7 mutations define a neurodegenerative disorder with lipofuscin and lipid droplet accumulation but without defining features of neuronal ceroid lipofuscinosis or lysosomal storage disorders. KCTD7 deficiency appears to cause an underlying autophagy-lysosome defect conserved in yeast, thereby assigning a biological role for KCTD7. Ann Neurol 2018;84:774-788.
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Affiliation(s)
- Kyle A Metz
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - Xinchen Teng
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD.,Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu Province, People's Republic of China
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - Heather M Lamb
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - Bart E Wagner
- Histopathology Department, Royal Hallamshire Hospital, Sheffield, United Kingdom
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
| | - Xianghui Chen
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu Province, People's Republic of China
| | - Yu Zhang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu Province, People's Republic of China
| | - Hee Jong Kim
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Michael E Meadow
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Tim Sen Wang
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD.,Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Edda D Haberlandt
- Clinical Department of Pediatrics I, Innsbruck Medical University, Innsbruck, Austria.,Department of Child and Youth Health, Hospital of Dornbirn, Dornbirn, Austria
| | - Glenn W Anderson
- Histopathology Department, Great Ormond Street Hospital for Children, London, United Kingdom
| | | | - Weimin Bi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
| | - Thomas C Markello
- NIH Undiagnosed Diseases Program, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD
| | - Marsha Pratt
- Department of Pediatrics, University of Oklahoma College of Medicine, Oklahoma City, OK
| | - Nawal Makhseed
- Department of Pediatrics, Jahra Hospital, Ministry of Health, Al Jahra, Kuwait
| | - Adolfo Garnica
- Department of Pediatrics, University of Arkansas for Medical Sciences and Arkansas Children's Hospital, Little Rock, AR
| | - Noelle R Danylchuk
- Department of Pediatrics, University of Arkansas for Medical Sciences and Arkansas Children's Hospital, Little Rock, AR
| | - Thomas A Burrow
- Department of Pediatrics, University of Arkansas for Medical Sciences and Arkansas Children's Hospital, Little Rock, AR
| | - Parul Jayakar
- Division of Genetics and Metabolism, Nicklaus Children's Hospital, Miami, FL
| | | | - Satish Agadi
- Department of Neurology, Texas Children's Hospital, Houston, TX
| | | | | | - Michael Alber
- Pediatric Neurology and Developmental Medicine, University of Tübingen, Tübingen, Germany
| | | | - Katrina Peariso
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | - Min Tsui Ong
- Department of Paediatric Neurology, Sheffield Children's National Health Service Foundation Trust, Sheffield, United Kingdom
| | - Santosh R Mordekar
- Department of Paediatric Neurology, Sheffield Children's National Health Service Foundation Trust, Sheffield, United Kingdom
| | - Michael J Parker
- Sheffield Clinical Genetics Service, Sheffield Children's National Health Service Foundation Trust, Sheffield, United Kingdom
| | - Daniel Crooks
- Department of Neuropathology, Walton Centre National Health Service Foundation Trust, Liverpool, United Kingdom
| | - Pankaj B Agrawal
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Gerard T Berry
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | | | - Yaping Yang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
| | - Gustavo H B Maegawa
- Department of Pediatrics/Genetics and Metabolism, University of Florida, Gainesville, FL
| | - Abdel Aouacheria
- Montpellier Institute of Evolution Sciences, University of Montpellier, CNRS, EPHE, IRD, Montpellier, France
| | - Janet G Markle
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - James A Wohlschlegel
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, Los Angeles, CA
| | - Adam L Hartman
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - J Marie Hardwick
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD.,Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD
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Chen X, Wang G, Zhang Y, Dayhoff-Brannigan M, Diny NL, Zhao M, He G, Sing CN, Metz KA, Stolp ZD, Aouacheria A, Cheng WC, Hardwick JM, Teng X. Whi2 is a conserved negative regulator of TORC1 in response to low amino acids. PLoS Genet 2018; 14:e1007592. [PMID: 30142151 PMCID: PMC6126876 DOI: 10.1371/journal.pgen.1007592] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 09/06/2018] [Accepted: 07/26/2018] [Indexed: 01/29/2023] Open
Abstract
Yeast WHI2 was originally identified in a genetic screen for regulators of cell cycle arrest and later suggested to function in general stress responses. However, the function of Whi2 is unknown. Whi2 has predicted structure and sequence similarity to human KCTD family proteins, which have been implicated in several cancers and are causally associated with neurological disorders but are largely uncharacterized. The identification of conserved functions between these yeast and human proteins may provide insight into disease mechanisms. We report that yeast WHI2 is a new negative regulator of TORC1 required to suppress TORC1 activity and cell growth specifically in response to low amino acids. In contrast to current opinion, WHI2 is dispensable for TORC1 inhibition in low glucose. The only widely conserved mechanism that actively suppresses both yeast and mammalian TORC1 specifically in response to low amino acids is the conserved SEACIT/GATOR1 complex that inactivates the TORC1-activating RAG-like GTPases. Unexpectedly, Whi2 acts independently and simultaneously with these established GATOR1-like Npr2-Npr3-Iml1 and RAG-like Gtr1-Gtr2 complexes, and also acts independently of the PKA pathway. Instead, Whi2 inhibits TORC1 activity through its binding partners, protein phosphatases Psr1 and Psr2, which were previously thought to only regulate amino acid levels downstream of TORC1. Furthermore, the ability to suppress TORC1 is conserved in the SKP1/BTB/POZ domain-containing, Whi2-like human protein KCTD11 but not other KCTD family members tested. Yeast and human cells respond to declining levels of available nutrients to prepare ahead for leaner times. The detailed mechanisms of nutrient sensing are not well understood, but defects in these processes have key roles in diseases such as cancer. The evolutionarily conserved protein complex TORC1 is the control hub for responding to both high and low nutrients, particularly amino acids. We identified yeast Whi2 and the human tumor suppressor KCTD11 as novel suppressors of TORC1 activity in low amino acid conditions, and we investigated the detailed mechanisms for Whi2. Unexpectedly, Whi2 works differently from the usual mechanism where TORC1 is controlled by the SEACIT-Gtr complex (mammalian GATOR1-RAG complex). Furthermore, both the Whi2 and the SEACIT-Gtr pathways work independently and together in parallel to suppress TORC1. For this function, Whi2 requires its binding partners, the yeast protein phosphatases Psr1 and Psr2, which were previously thought to function downstream of TORC1 in amino acid signaling. These studies have important implications for human KCTD11 to help advance the understanding of its pathological role.
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Affiliation(s)
- Xianghui Chen
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - Guiqin Wang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - Yu Zhang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - Margaret Dayhoff-Brannigan
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, United States of America
| | - Nicola L. Diny
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, United States of America
| | - Mingjun Zhao
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - Ge He
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - Cierra N. Sing
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, United States of America
| | - Kyle A. Metz
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, United States of America
| | - Zachary D. Stolp
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, United States of America
| | - Abdel Aouacheria
- ISEM, Institut des Sciences de l’Evolution de Montpellier, Université de Montpellier, CNRS, EPHE, IRD, Montpellier, France
| | - Wen-Chih Cheng
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, United States of America
| | - J. Marie Hardwick
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, United States of America
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
- * E-mail: (JMH); (XT)
| | - Xinchen Teng
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, United States of America
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
- * E-mail: (JMH); (XT)
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He J, Lin H, Li JJ, Su HZ, Wang DN, Lin Y, Wang N, Chen WJ. Identification of a Novel Homozygous Splice-Site Mutation in SCARB2 that Causes Progressive Myoclonus Epilepsy with or without Renal Failure. Chin Med J (Engl) 2018; 131:1575-1583. [PMID: 29941711 PMCID: PMC6032684 DOI: 10.4103/0366-6999.235113] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND Progressive myoclonus epilepsies (PMEs) comprise a group of rare genetic disorders characterized by action myoclonus, epileptic seizures, and ataxia with progressive neurologic decline. Due to clinical and genetic heterogeneity of PMEs, it is difficult to decide which genes are affected. The aim of this study was to report an action myoclonus with or without renal failure syndrome (EPM4) family and summarize the clinical and genetic characteristics of all reported EPM4 patients. METHODS In the present study, targeted next-generation sequencing (NGS) was applied to screen causative genes in a Chinese PME family. The candidate variant was further confirmed by cosegregation analysis and further functional analysis, including the reverse transcription polymerase chain reaction and Western blot of the proband's muscle. Moreover, literature data on the clinical and mutational features of all reported EPM4 patients were reviewed. RESULTS The gene analysis revealed a novel homozygous splicing mutation (c.995-1G>A) of the SCARB2 gene in two brothers. Further functional analysis revealed that this mutation led to loss function of the SCARB2 protein. The classification of the candidate variant, according to the American College of Medical Genetics and Genomics standards and guidelines and functional analysis, was pathogenic. Therefore, these two brothers were finally diagnostically confirmed as EPM4. CONCLUSIONS These present results suggest the potential for targeted NGS to conduct a more rapid and precise diagnosis for PME patients. A literature review revealed that mutations in the different functional domains of SCARB2 appear to be associated with the phenotype of EPM4.
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Affiliation(s)
- Jin He
- Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005, China
| | - Han Lin
- Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005, China
| | - Jin-Jing Li
- Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005, China
| | - Hui-Zhen Su
- Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005, China
| | - Dan-Ni Wang
- Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005, China
| | - Yu Lin
- Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005, China
- Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350005, China
| | - Ning Wang
- Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005, China
- Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350005, China
| | - Wan-Jin Chen
- Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005, China
- Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian 350005, China
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Oyrer J, Maljevic S, Scheffer IE, Berkovic SF, Petrou S, Reid CA. Ion Channels in Genetic Epilepsy: From Genes and Mechanisms to Disease-Targeted Therapies. Pharmacol Rev 2018; 70:142-173. [PMID: 29263209 DOI: 10.1124/pr.117.014456] [Citation(s) in RCA: 163] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 10/02/2017] [Indexed: 12/19/2022] Open
Abstract
Epilepsy is a common and serious neurologic disease with a strong genetic component. Genetic studies have identified an increasing collection of disease-causing genes. The impact of these genetic discoveries is wide reaching-from precise diagnosis and classification of syndromes to the discovery and validation of new drug targets and the development of disease-targeted therapeutic strategies. About 25% of genes identified in epilepsy encode ion channels. Much of our understanding of disease mechanisms comes from work focused on this class of protein. In this study, we review the genetic, molecular, and physiologic evidence supporting the pathogenic role of a number of different voltage- and ligand-activated ion channels in genetic epilepsy. We also review proposed disease mechanisms for each ion channel and highlight targeted therapeutic strategies.
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Affiliation(s)
- Julia Oyrer
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
| | - Snezana Maljevic
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
| | - Ingrid E Scheffer
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
| | - Samuel F Berkovic
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
| | - Steven Petrou
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
| | - Christopher A Reid
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
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Chen T, Giri M, Xia Z, Subedi YN, Li Y. Genetic and epigenetic mechanisms of epilepsy: a review. Neuropsychiatr Dis Treat 2017; 13:1841-1859. [PMID: 28761347 PMCID: PMC5516882 DOI: 10.2147/ndt.s142032] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Epilepsy is a common episodic neurological disorder or condition characterized by recurrent epileptic seizures, and genetics seems to play a key role in its etiology. Early linkage studies have localized multiple loci that may harbor susceptibility genes to epilepsy, and mutational analyses have detected a number of mutations involved in both ion channel and nonion channel genes in patients with idiopathic epilepsy. Genome-wide studies of epilepsy have found copy number variants at 2q24.2-q24.3, 7q11.22, 15q11.2-q13.3, and 16p13.11-p13.2, some of which disrupt multiple genes, such as NRXN1, AUTS2, NLGN1, CNTNAP2, GRIN2A, PRRT2, NIPA2, and BMP5, implicated for neurodevelopmental disorders, including intellectual disability and autism. Unfortunately, only a few common genetic variants have been associated with epilepsy. Recent exome-sequencing studies have found some genetic mutations, most of which are located in nonion channel genes such as the LGI1, PRRT2, EFHC1, PRICKLE, RBFOX1, and DEPDC5 and in probands with rare forms of familial epilepsy, and some of these genes are involved with the neurodevelopment. Since epigenetics plays a role in neuronal function from embryogenesis and early brain development to tissue-specific gene expression, epigenetic regulation may contribute to the genetic mechanism of neurodevelopment through which a gene and the environment interacting with each other affect the development of epilepsy. This review focused on the analytic tools used to identify epilepsy and then provided a summary of recent linkage and association findings, indicating the existence of novel genes on several chromosomes for further understanding of the biology of epilepsy.
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Affiliation(s)
- Tian Chen
- Department of Health Management Center, Chongqing Three Gorges Central Hospital, Chongqing, People's Republic of China
| | - Mohan Giri
- National Center for Rheumatic Diseases, Ratopul, Gaushala, Kathmandu, Nepal
| | - Zhenyi Xia
- Department of Thoracic Surgery, Chongqing Three Gorges Central Hospital, Chongqing, People's Republic of China
| | - Yadu Nanda Subedi
- National Center for Rheumatic Diseases, Ratopul, Gaushala, Kathmandu, Nepal
| | - Yan Li
- Department of Health Management Center, Chongqing Three Gorges Central Hospital, Chongqing, People's Republic of China
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Moen MN, Fjær R, Hamdani EH, Laerdahl JK, Menchini RJ, Vigeland MD, Sheng Y, Undlien DE, Hassel B, Salih MA, El Khashab HY, Selmer KK, Chaudhry FA. Pathogenic variants in KCTD7 perturb neuronal K+ fluxes and glutamine transport. Brain 2016; 139:3109-3120. [PMID: 27742667 DOI: 10.1093/brain/aww244] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 06/11/2016] [Accepted: 08/17/2016] [Indexed: 12/11/2022] Open
Abstract
Progressive myoclonus epilepsy is a heterogeneous group of disorders characterized by myoclonic and tonic-clonic seizures, ataxia and cognitive decline. We here present two affected brothers. At 9 months of age the elder brother developed ataxia and myoclonic jerks. In his second year he lost the ability to walk and talk, and he developed drug-resistant progressive myoclonus epilepsy. The cerebrospinal fluid level of glutamate was decreased while glutamine was increased. His younger brother manifested similar symptoms from 6 months of age. By exome sequencing of the proband we identified a novel homozygous frameshift variant in the potassium channel tetramerization domain 7 (KCTD7) gene (NM_153033.1:c.696delT: p.F232fs), which results in a truncated protein. The identified F232fs variant is inherited in an autosomal recessive manner, and the healthy consanguineous parents carry the variant in a heterozygous state. Bioinformatic analyses and structure modelling showed that KCTD7 is a highly conserved protein, structurally similar to KCTD5 and several voltage-gated potassium channels, and that it may form homo- or heteromultimers. By heterologous expression in Xenopus laevis oocytes, we demonstrate that wild-type KCTD7 hyperpolarizes cells in a K+ dependent manner and regulates activity of the neuronal glutamine transporter SAT2 (Slc38a2), while the F232fs variant impairs K+ fluxes and obliterates SAT2-dependent glutamine transport. Characterization of four additional disease-causing variants (R94W, R184C, N273I, Y276C) bolster these results and reveal the molecular mechanisms involved in the pathophysiology of KCTD7-related progressive myoclonus epilepsy. Thus, our data demonstrate that KCTD7 has an impact on K+ fluxes, neurotransmitter synthesis and neuronal function, and that malfunction of the encoded protein may lead to progressive myoclonus epilepsy.
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Affiliation(s)
- Marivi Nabong Moen
- 1 The Institute of Basic Medical Sciences, Department of Molecular Medicine, University of Oslo, Oslo, Norway
| | - Roar Fjær
- 2 Department of Medical Genetics, Oslo University Hospital and University of Oslo, Norway
| | - El Hassan Hamdani
- 1 The Institute of Basic Medical Sciences, Department of Molecular Medicine, University of Oslo, Oslo, Norway.,3 Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
| | - Jon K Laerdahl
- 4 Department of Microbiology, Oslo University Hospital, Oslo, Norway.,5 Bioinformatics Core Facility, Department of Informatics, University of Oslo, Oslo, Norway
| | - Robin Johansen Menchini
- 1 The Institute of Basic Medical Sciences, Department of Molecular Medicine, University of Oslo, Oslo, Norway
| | - Magnus Dehli Vigeland
- 2 Department of Medical Genetics, Oslo University Hospital and University of Oslo, Norway
| | - Ying Sheng
- 2 Department of Medical Genetics, Oslo University Hospital and University of Oslo, Norway
| | - Dag Erik Undlien
- 2 Department of Medical Genetics, Oslo University Hospital and University of Oslo, Norway
| | - Bjørnar Hassel
- 6 Department of Complex Neurology and Neurohabilitation, Oslo University Hospital, Oslo, Norway
| | - Mustafa A Salih
- 7 Division of Paediatric Neurology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Heba Y El Khashab
- 7 Division of Paediatric Neurology, College of Medicine, King Saud University, Riyadh, Saudi Arabia.,8 Department of Paediatrics, Ain Shams University, Cairo, Egypt
| | - Kaja Kristine Selmer
- 2 Department of Medical Genetics, Oslo University Hospital and University of Oslo, Norway.,9 National Centre for Rare Epilepsy-related Disorders, Oslo University Hospital, Oslo, Norway
| | - Farrukh Abbas Chaudhry
- 1 The Institute of Basic Medical Sciences, Department of Molecular Medicine, University of Oslo, Oslo, Norway .,3 Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
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Seaby EG, Gilbert RD, Pengelly RJ, Andreoletti G, Clarke A, Ennis S. Progressive myoclonic epilepsy with Fanconi syndrome. JRSM Open 2016; 7:2054270415623145. [PMID: 27293772 PMCID: PMC4900196 DOI: 10.1177/2054270415623145] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
This report illustrates the difficulties in diagnosing complex cases and demonstrates how whole exome sequencing can resolve complex phenotypes.
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Affiliation(s)
- Eleanor G Seaby
- Human Genetics and Genomic Medicine, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK
| | - Rodney D Gilbert
- Wessex Regional Paediatric Nephro-Urology Service, Southampton Children's Hospital, Southampton SO16 6YD, UK; Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | - Reuben J Pengelly
- Human Genetics and Genomic Medicine, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK
| | - Gaia Andreoletti
- Human Genetics and Genomic Medicine, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK
| | - Antonia Clarke
- Department of Paediatric Neurology, St George's Hospital, London SW17 OQT, UK
| | - Sarah Ennis
- Human Genetics and Genomic Medicine, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK
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Gonsales MC, Montenegro MA, Soler CV, Coan AC, Guerreiro MM, Lopes-Cendes I. Recent developments in the genetics of childhood epileptic encephalopathies: impact in clinical practice. ARQUIVOS DE NEURO-PSIQUIATRIA 2015; 73:946-58. [PMID: 26517219 DOI: 10.1590/0004-282x20150122] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 07/20/2015] [Indexed: 01/03/2023]
Abstract
Recent advances in molecular genetics led to the discovery of several genes for childhood epileptic encephalopathies (CEEs). As the knowledge about the genes associated with this group of disorders develops, it becomes evident that CEEs present a number of specific genetic characteristics, which will influence the use of molecular testing for clinical purposes. Among these, there are the presence of marked genetic heterogeneity and the high frequency of de novo mutations. Therefore, the main objectives of this review paper are to present and discuss current knowledge regarding i) new genetic findings in CEEs, ii) phenotype-genotype correlations in different forms of CEEs; and, most importantly, iii) the impact of these new findings in clinical practice. Accompanying this text we have included a comprehensive table, containing the list of genes currently known to be involved in the etiology of CEEs.
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Affiliation(s)
- Marina C Gonsales
- Instituto Brasileiro de Neurociências e Neurotecnologia, Faculdade de Ciências Médicas, Universidade de Campinas, Campinas, SP, Brazil
| | - Maria Augusta Montenegro
- Instituto Brasileiro de Neurociências e Neurotecnologia, Faculdade de Ciências Médicas, Universidade de Campinas, Campinas, SP, Brazil
| | - Camila V Soler
- Instituto Brasileiro de Neurociências e Neurotecnologia, Faculdade de Ciências Médicas, Universidade de Campinas, Campinas, SP, Brazil
| | - Ana Carolina Coan
- Instituto Brasileiro de Neurociências e Neurotecnologia, Faculdade de Ciências Médicas, Universidade de Campinas, Campinas, SP, Brazil
| | - Marilisa M Guerreiro
- Instituto Brasileiro de Neurociências e Neurotecnologia, Faculdade de Ciências Médicas, Universidade de Campinas, Campinas, SP, Brazil
| | - Iscia Lopes-Cendes
- Instituto Brasileiro de Neurociências e Neurotecnologia, Faculdade de Ciências Médicas, Universidade de Campinas, Campinas, SP, Brazil
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Mencacci N, Rubio-Agusti I, Zdebik A, Asmus F, Ludtmann M, Ryten M, Plagnol V, Hauser AK, Bandres-Ciga S, Bettencourt C, Forabosco P, Hughes D, Soutar M, Peall K, Morris H, Trabzuni D, Tekman M, Stanescu H, Kleta R, Carecchio M, Zorzi G, Nardocci N, Garavaglia B, Lohmann E, Weissbach A, Klein C, Hardy J, Pittman A, Foltynie T, Abramov A, Gasser T, Bhatia K, Wood N. A missense mutation in KCTD17 causes autosomal dominant myoclonus-dystonia. Am J Hum Genet 2015; 96:938-47. [PMID: 25983243 DOI: 10.1016/j.ajhg.2015.04.008] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 04/13/2015] [Indexed: 12/25/2022] Open
Abstract
Myoclonus-dystonia (M-D) is a rare movement disorder characterized by a combination of non-epileptic myoclonic jerks and dystonia. SGCE mutations represent a major cause for familial M-D being responsible for 30%-50% of cases. After excluding SGCE mutations, we identified through a combination of linkage analysis and whole-exome sequencing KCTD17 c.434 G>A p.(Arg145His) as the only segregating variant in a dominant British pedigree with seven subjects affected by M-D. A subsequent screening in a cohort of M-D cases without mutations in SGCE revealed the same KCTD17 variant in a German family. The clinical presentation of the KCTD17-mutated cases was distinct from the phenotype usually observed in M-D due to SGCE mutations. All cases initially presented with mild myoclonus affecting the upper limbs. Dystonia showed a progressive course, with increasing severity of symptoms and spreading from the cranio-cervical region to other sites. KCTD17 is abundantly expressed in all brain regions with the highest expression in the putamen. Weighted gene co-expression network analysis, based on mRNA expression profile of brain samples from neuropathologically healthy individuals, showed that KCTD17 is part of a putamen gene network, which is significantly enriched for dystonia genes. Functional annotation of the network showed an over-representation of genes involved in post-synaptic dopaminergic transmission. Functional studies in mutation bearing fibroblasts demonstrated abnormalities in endoplasmic reticulum-dependent calcium signaling. In conclusion, we demonstrate that the KCTD17 c.434 G>A p.(Arg145His) mutation causes autosomal dominant M-D. Further functional studies are warranted to further characterize the nature of KCTD17 contribution to the molecular pathogenesis of M-D.
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Mole SE, Cotman SL. Genetics of the neuronal ceroid lipofuscinoses (Batten disease). Biochim Biophys Acta Mol Basis Dis 2015; 1852:2237-41. [PMID: 26026925 DOI: 10.1016/j.bbadis.2015.05.011] [Citation(s) in RCA: 214] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 05/12/2015] [Accepted: 05/18/2015] [Indexed: 11/17/2022]
Abstract
The neuronal ceroid lipofuscinoses (NCLs) are a group of inherited neurodegenerative disorders that affect children and adults and are grouped together by similar clinical features and the accumulation of autofluorescent storage material. More than a dozen genes containing over 430 mutations underlying human NCLs have been identified. These genes encode lysosomal enzymes (CLN1, CLN2, CLN10, CLN13), a soluble lysosomal protein (CLN5), a protein in the secretory pathway (CLN11), two cytoplasmic proteins that also peripherally associate with membranes (CLN4, CLN14), and many transmembrane proteins with different subcellular locations (CLN3, CLN6, CLN7, CLN8, CLN12). For most NCLs, the function of the causative gene has not been fully defined. Most of the mutations in these genes are associated with a typical disease phenotype, but some result in variable disease onset, severity, and progression, including distinct clinical phenotypes. There remain disease subgroups with unknown molecular genetic backgrounds. This article is part of a Special Issue entitled: "Current Research on the Neuronal Ceroid Lipofuscinoses (Batten Disease)."
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Affiliation(s)
- Sara E Mole
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London, WC1E 6BT, UK; UCL Institute of Child Health and Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK.
| | - Susan L Cotman
- Center for Human Genetic Research, Department of Neurology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114, USA
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Cell biology of the NCL proteins: What they do and don't do. Biochim Biophys Acta Mol Basis Dis 2015; 1852:2242-55. [PMID: 25962910 DOI: 10.1016/j.bbadis.2015.04.027] [Citation(s) in RCA: 128] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 04/23/2015] [Accepted: 04/24/2015] [Indexed: 02/06/2023]
Abstract
The fatal, primarily childhood neurodegenerative disorders, neuronal ceroid lipofuscinoses (NCLs), are currently associated with mutations in 13 genes. The protein products of these genes (CLN1 to CLN14) differ in their function and their intracellular localization. NCL-associated proteins have been localized mostly in lysosomes (CLN1, CLN2, CLN3, CLN5, CLN7, CLN10, CLN12 and CLN13) but also in the Endoplasmic Reticulum (CLN6 and CLN8), or in the cytosol associated to vesicular membranes (CLN4 and CLN14). Some of them such as CLN1 (palmitoyl protein thioesterase 1), CLN2 (tripeptidyl-peptidase 1), CLN5, CLN10 (cathepsin D), and CLN13 (cathepsin F), are lysosomal soluble proteins; others like CLN3, CLN7, and CLN12, have been proposed to be lysosomal transmembrane proteins. In this review, we give our views and attempt to summarize the proposed and confirmed functions of each NCL protein and describe and discuss research results published since the last review on NCL proteins. This article is part of a Special Issue entitled: "Current Research on the Neuronal Ceroid Lipofuscinoses (Batten Disease)".
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Lunnon K, Smith RG, Cooper I, Greenbaum L, Mill J, Beeri MS. Blood methylomic signatures of presymptomatic dementia in elderly subjects with type 2 diabetes mellitus. Neurobiol Aging 2015; 36:1600.e1-4. [PMID: 25585531 PMCID: PMC5747361 DOI: 10.1016/j.neurobiolaging.2014.12.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/15/2014] [Indexed: 12/30/2022]
Abstract
Due to an aging population, the incidence of dementia is steadily rising. The ability to identify early markers in blood, which appear before the onset of clinical symptoms is of considerable interest to allow early intervention, particularly in "high risk" groups such as those with type 2 diabetes. Here, we present a longitudinal study of genome-wide DNA methylation in whole blood from 18 elderly individuals with type 2 diabetes who developed presymptomatic dementia within an 18-month period following baseline assessment and 18 age-, sex-, and education-matched controls who maintained normal cognitive function. We identified a significant overlap in methylomic differences between groups at baseline and follow-up, with 8 CpG sites being consistently differentially methylated above our nominal significance threshold before symptoms at baseline and at 18 months follow up, after a diagnosis of presymptomatic dementia. Finally, we report a significant overlap between DNA methylation differences identified in converters, only after they develop symptoms of dementia, with differences at the same loci in blood samples from patients with clinically diagnosed Alzheimer's disease compared with unaffected control subjects.
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Affiliation(s)
- Katie Lunnon
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, Devon, UK.
| | - Rebecca G Smith
- MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College, London, London, UK
| | - Itzik Cooper
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Ramat Gan, Israel
| | - Lior Greenbaum
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Ramat Gan, Israel; Department of Neurology, Sheba Medical Center, Ramat Gan, Israel
| | - Jonathan Mill
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, Devon, UK; MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College, London, London, UK
| | - Michal Schnaider Beeri
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Ramat Gan, Israel; Department of Psychiatry, The Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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Craiu D, Dragostin O, Dica A, Hoffman-Zacharska D, Gos M, Bastian AE, Gherghiceanu M, Rolfs A, Nahavandi N, Craiu M, Iliescu C. Rett-like onset in late-infantile neuronal ceroid lipofuscinosis (CLN7) caused by compound heterozygous mutation in the MFSD8 gene and review of the literature data on clinical onset signs. Eur J Paediatr Neurol 2015; 19:78-86. [PMID: 25439737 DOI: 10.1016/j.ejpn.2014.07.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 07/16/2014] [Accepted: 07/27/2014] [Indexed: 02/05/2023]
Abstract
BACKGROUND We present clinical and molecular findings of a patient with ceroid-lipofuscinosis CLN7, with a compound heterozygous mutation of the MFSD8 gene, with Rett syndrome clinical signs onset and a later development of full picture of vLINCL. CASE PRESENTATION A 7 years-old female patient with normal development until the age 12 months, developed Rett like clinical picture (psychomotor regression, microcephaly, stereotypic hands movements in the midline, hyperventilation episodes) present at the onset of her condition (age 18 months), features still present at the initial evaluation in our clinic at age 5 years. RESULTS MECP2 (methyl CpG binding protein 2) gene mutation was negative. At age 6 years she was readmitted for severe ataxia and blindness, seizures, and severe developmental regression leading to NCL (neuronal ceroid lipofuscinosis) suspicion. EEG showed slow background with IRDA (intermittent rhythmic delta activity). A conjunctive biopsy showed abnormal curvilinear and fingerprint lysosomal deposits, and genetic analysis revealed two heterozygous mutations of MFSD8 gene (c.881C > A p.Thr294Lys and c.754 + 2T > A) each inherited from carrier parents and a heterozygous variant (c.470A>C p.Asp157Ala) of CLN5 gene. CONCLUSION NCL should be suspected and MFSD8 genetic testing should also be considered in patients with Rett like phenotype at onset and negative MECP2 mutation. Such cases should be carefully and frequently re-evaluated in order to avoid delayed diagnosis and offer proper genetic advice to the family. In our knowledge, this might be the first case of CLN7 disease with Rett like onset described in the literature, which developed typical vLINCL clinical phenotype after age 5.5 years. A short review of the literature showing NCL onset modalities is presented.
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Affiliation(s)
- Dana Craiu
- "Carol Davila" University of Medicine Bucharest, Department of Neurology, Pediatric Neurology, Psychiatry, Neurosurgery, Discipline Pediatric Neurology, Romania; Pediatric Neurology Clinic, "Alexandru Obregia" Clinical Psychiatric Hospital, Şos. Berceni 10-12, Sector 4, Bucharest, Romania.
| | - Octavia Dragostin
- Pediatric Neurology Clinic, "Alexandru Obregia" Clinical Psychiatric Hospital, Şos. Berceni 10-12, Sector 4, Bucharest, Romania.
| | - Alice Dica
- Pediatric Neurology Clinic, Research Department, "Alexandru Obregia" Clinical Psychiatric Hospital, Şos. Berceni 10-12, Sector 4, Bucharest, Romania.
| | - Dorota Hoffman-Zacharska
- Department of Medical Genetics, Institute of Mother and Child, Kasprzaka 17A, 01-211 Warsaw, Poland.
| | - Monika Gos
- Department of Medical Genetics, Institute of Mother and Child, Kasprzaka 17A, 01-211 Warsaw, Poland.
| | - Alexandra Eugenia Bastian
- "Carol Davila" University of Medicine Bucharest, Department II, Dental Medicine, Pathology Discpline, Romania; Pathology Lab., Colentina University Hospital, Sos Stefan cel Mare 19-21, Sector 2, 020125 Bucharest, Romania.
| | - Mihaela Gherghiceanu
- Ultrastructural Pathology Lab., 'Victor Babes' National Institute of Pathology, 99-101 Spl. Independentei, 050096 Bucharest 5, Romania.
| | - Arndt Rolfs
- Albrecht-Kossel-Institute for Neurogenetics, Medical Faculty, University of Rostock, Gehlsheimerstrasse 20, 18157 Rostock, Germany; Centogene AG, Schillingallee 69, 18057 Rostock, Germany.
| | | | - Mihai Craiu
- "Carol Davila" University of Medicine Bucharest, Department of Pediatrics and Medical Genetics, Discipline Pediatrics, Romania; Pediatric II Clinic, "Alfred Rusescu" Clinical Pediatric Hospital, Institute of Mother and Child Health, B-dul Lacul Tei No. 120, Sector 2, Bucharest, Romania.
| | - Catrinel Iliescu
- "Carol Davila" University of Medicine Bucharest, Department of Neurology, Pediatric Neurology, Psychiatry, Neurosurgery, Discipline Pediatric Neurology, Romania; Pediatric Neurology Clinic, "Alexandru Obregia" Clinical Psychiatric Hospital, Şos. Berceni 10-12, Sector 4, Bucharest, Romania.
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