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Wallace NS, Gadbery JE, Cohen CI, Kendall AK, Jackson LP. Tepsin binds LC3B to promote ATG9A trafficking and delivery. Mol Biol Cell 2024; 35:ar56. [PMID: 38381558 PMCID: PMC11064669 DOI: 10.1091/mbc.e23-09-0359-t] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 02/07/2024] [Accepted: 02/16/2024] [Indexed: 02/23/2024] Open
Abstract
Tepsin is an established accessory protein found in Adaptor Protein 4 (AP-4) coated vesicles, but the biological role of tepsin remains unknown. AP-4 vesicles originate at the trans-Golgi network (TGN) and target the delivery of ATG9A, a scramblase required for autophagosome biogenesis, to the cell periphery. Using in silico methods, we identified a putative LC3-Interacting Region (LIR) motif in tepsin. Biochemical experiments using purified recombinant proteins indicate tepsin directly binds LC3B preferentially over other members of the mammalian ATG8 family. Calorimetry and structural modeling data indicate this interaction occurs with micromolar affinity using the established LC3B LIR docking site. Loss of tepsin in cultured cells dysregulates ATG9A export from the TGN as well as ATG9A distribution at the cell periphery. Tepsin depletion in a mRFP-GFP-LC3B HeLa reporter cell line using siRNA knockdown increases autophagosome volume and number, but does not appear to affect flux through the autophagic pathway. Reintroduction of wild-type tepsin partially rescues ATG9A cargo trafficking defects. In contrast, reintroducing tepsin with a mutated LIR motif or missing N-terminus drives diffuse ATG9A subcellular distribution. Together, these data suggest roles for tepsin in cargo export from the TGN; ensuring delivery of ATG9A-positive vesicles; and in overall maintenance of autophagosome structure.
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Affiliation(s)
- Natalie S. Wallace
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37232
| | - John E. Gadbery
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37232
| | - Cameron I. Cohen
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37232
| | - Amy K. Kendall
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37232
| | - Lauren P. Jackson
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37232
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37232
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2
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Janzing AM, Eklund E, De Koning TJ, Eggink H. Clinical Characteristics Suggestive of a Genetic Cause in Cerebral Palsy: A Systematic Review. Pediatr Neurol 2024; 153:144-151. [PMID: 38382247 DOI: 10.1016/j.pediatrneurol.2024.01.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 01/11/2024] [Accepted: 01/27/2024] [Indexed: 02/23/2024]
Abstract
BACKGROUND Cerebral palsy (CP) is a clinical diagnosis and was long categorized as an acquired disorder, but more and more genetic etiologies are being identified. This review aims to identify the clinical characteristics that are associated with genetic CP to aid clinicians in selecting candidates for genetic testing. METHODS The PubMed database was systematically searched to identify genes associated with CP. The clinical characteristics accompanying these genetic forms of CP were compared with published data of large CP populations resulting in the identification of potential indicators of genetic CP. RESULLTS Of 1930 articles retrieved, 134 were included. In these, 55 CP genes (described in two or more cases, n = 272) and 79 candidate genes (described in only one case) were reported. The most frequently CP-associated genes were PLP1 (21 cases), ARG1 (17 cases), and CTNNB1 (13 cases). Dyskinesia and the absence of spasticity were identified as strong potential indicators of genetic CP. Presence of intellectual disability, no preterm birth, and no unilateral distribution of symptoms were classified as moderate genetic indicators. CONCLUSIONS Genetic causes of CP are increasingly identified. The clinical characteristics associated with genetic CP can aid clinicians regarding to which individual with CP to offer genetic testing. The identified potential genetic indicators need to be validated in large CP cohorts but can provide the first step toward a diagnostic algorithm for genetic CP.
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Affiliation(s)
- Anna M Janzing
- Department of Neurology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Expertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Erik Eklund
- Faculty of Medicine, Department of Clinical Sciences, Pediatrics, Lund University, Lund, Sweden
| | - Tom J De Koning
- Expertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, The Netherlands; Faculty of Medicine, Department of Clinical Sciences, Pediatrics, Lund University, Lund, Sweden; Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Hendriekje Eggink
- Department of Neurology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Expertise Center Movement Disorders Groningen, University Medical Center Groningen, Groningen, The Netherlands.
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3
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Caracci MO, Pizarro H, Alarcón-Godoy C, Fuentealba LM, Farfán P, De Pace R, Santibañez N, Cavieres VA, Pástor TP, Bonifacino JS, Mardones GA, Marzolo MP. The Reelin receptor ApoER2 is a cargo for the adaptor protein complex AP-4: Implications for Hereditary Spastic Paraplegia. Prog Neurobiol 2024; 234:102575. [PMID: 38281682 PMCID: PMC10979513 DOI: 10.1016/j.pneurobio.2024.102575] [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: 07/03/2023] [Revised: 01/11/2024] [Accepted: 01/23/2024] [Indexed: 01/30/2024]
Abstract
Adaptor protein complex 4 (AP-4) is a heterotetrameric complex that promotes export of selected cargo proteins from the trans-Golgi network. Mutations in each of the AP-4 subunits cause a complicated form of Hereditary Spastic Paraplegia (HSP). Herein, we report that ApoER2, a receptor in the Reelin signaling pathway, is a cargo of the AP-4 complex. We identify the motif ISSF/Y within the ApoER2 cytosolic domain as necessary for interaction with the canonical signal-binding pocket of the µ4 (AP4M1) subunit of AP-4. AP4E1- knock-out (KO) HeLa cells and hippocampal neurons from Ap4e1-KO mice display increased co-localization of ApoER2 with Golgi markers. Furthermore, hippocampal neurons from Ap4e1-KO mice and AP4M1-KO human iPSC-derived cortical i3Neurons exhibit reduced ApoER2 protein expression. Analyses of biosynthetic transport of ApoER2 reveal differential post-Golgi trafficking of the receptor, with lower axonal distribution in KO compared to wild-type neurons, indicating a role of AP-4 and the ISSF/Y motif in the axonal localization of ApoER2. Finally, analyses of Reelin signaling in mouse hippocampal and human cortical KO neurons show that AP4 deficiency causes no changes in Reelin-dependent activation of the AKT pathway and only mild changes in Reelin-induced dendritic arborization, but reduces Reelin-induced ERK phosphorylation, CREB activation, and Golgi deployment. This work thus establishes ApoER2 as a novel cargo of the AP-4 complex, suggesting that defects in the trafficking of this receptor and in the Reelin signaling pathway could contribute to the pathogenesis of HSP caused by mutations in AP-4 subunits.
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Affiliation(s)
- Mario O Caracci
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago, Chile
| | - Héctor Pizarro
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago, Chile
| | - Carlos Alarcón-Godoy
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago, Chile
| | - Luz M Fuentealba
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago, Chile
| | - Pamela Farfán
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago, Chile
| | - Raffaella De Pace
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Natacha Santibañez
- Instituto de Patología Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Viviana A Cavieres
- Departamento de Ciencias Biológicas y Químicas, Fac. Med y Ciencia, USS, Santiago, Chile
| | - Tammy P Pástor
- Escuela de Medicina, Facultad de Medicina y Ciencia, Universidad San Sebastián, Valdivia, Chile
| | - Juan S Bonifacino
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Gonzalo A Mardones
- Escuela de Medicina, Facultad de Medicina y Ciencia, Universidad San Sebastián, Valdivia, Chile
| | - María-Paz Marzolo
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago, Chile.
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4
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Caracci MO, Pizarro H, Alarcón-Godoy C, Fuentealba LM, Farfán P, Pace RD, Santibañez N, Cavieres VA, Pástor TP, Bonifacino JS, Mardones GA, Marzolo MP. The Reelin Receptor ApoER2 is a Cargo for the Adaptor Protein Complex AP-4: Implications for Hereditary Spastic Paraplegia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.21.572896. [PMID: 38187774 PMCID: PMC10769347 DOI: 10.1101/2023.12.21.572896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Adaptor protein complex 4 (AP-4) is a heterotetrameric complex that promotes protein export from the trans -Golgi network. Mutations in each of the AP-4 subunits cause a complicated form of Hereditary Spastic Paraplegia (HSP). Herein, we report that ApoER2, a receptor in the Reelin signaling pathway, is a cargo of the AP-4 complex. We identify the motif ISSF/Y within the ApoER2 cytosolic domain as necessary for interaction with the canonical signal-binding pocket of the µ4 (AP4M1) subunit of AP-4. AP4E1 -knock-out (KO) HeLa cells and hippocampal neurons from Ap4e1 -KO mice display increased Golgi localization of ApoER2. Furthermore, hippocampal neurons from Ap4e1 -KO mice and AP4M1 -KO human iPSC-derived cortical i3Neurons exhibit reduced ApoER2 protein expression. Analyses of biosynthetic transport of ApoER2 reveal differential post-Golgi trafficking of the receptor, with lower axonal distribution in KO compared to wild-type neurons, indicating a role of AP-4 and the ISSF/Y motif in the axonal localization of ApoER2. Finally, analyses of Reelin signaling in mouse hippocampal and human cortical KO neurons show that AP4 deficiency causes no changes in Reelin-dependent activation of the AKT pathway and only mild changes in Reelin-induced dendritic arborization, but reduces Reelin-induced ERK phosphorylation, CREB activation, and Golgi deployment. Altogether, this work establishes ApoER2 as a novel cargo of the AP-4 complex, suggesting that defects in the trafficking of this receptor and in the Reelin signaling pathway could contribute to the pathogenesis of HSP caused by mutations in AP-4 subunits.
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5
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Pembridge OG, Wallace NS, Clements TP, Jackson LP. AP-4 loss in CRISPR-edited zebrafish affects early embryo development. Adv Biol Regul 2023; 87:100945. [PMID: 36642642 PMCID: PMC9992121 DOI: 10.1016/j.jbior.2022.100945] [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: 11/11/2022] [Revised: 12/12/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022]
Abstract
Mutations in the heterotetrametric adaptor protein 4 (AP-4; ε/β4/μ4/σ4 subunits) membrane trafficking coat complex lead to complex neurological disorders characterized by spastic paraplegia, microcephaly, and intellectual disabilities. Understanding molecular mechanisms underlying these disorders continues to emerge with recent identification of an essential autophagy protein, ATG9A, as an AP-4 cargo. Significant progress has been made uncovering AP-4 function in cell culture and patient-derived cell lines, and ATG9A trafficking by AP-4 is considered a potential target for gene therapy approaches. In contrast, understanding how AP-4 trafficking affects development and function at the organismal level has long been hindered by loss of conserved AP-4 genes in key model systems (S. cerevisiae, C. elegans, D. melanogaster). However, zebrafish (Danio rerio) have retained AP-4 and can serve as an important model system for studying both the nervous system and overall development. We undertook gene editing in zebrafish using a CRISPR-ExoCas9 knockout system to determine how loss of single AP-4, or its accessory protein tepsin, genes affect embryo development 24 h post-fertilization (hpf). Single gene-edited embryos display abnormal head morphology and neural necrosis. We further conducted the first exploration of how AP-4 single gene knockouts in zebrafish embryos affect expression levels and patterns of two autophagy genes, atg9a and map1lc3b. This work suggests zebrafish may be further adapted and developed as a tool to uncover AP-4 function in membrane trafficking and autophagy in the context of a model organism.
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Affiliation(s)
- Olivia G Pembridge
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - Natalie S Wallace
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA; Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
| | - Thomas P Clements
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - Lauren P Jackson
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA; Center for Structural Biology, Vanderbilt University, Nashville, TN, USA; Department of Biochemistry, Vanderbilt University, Nashville, TN, USA.
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Xin C, Guan X, Wang L, Liu J. Integrative Multi-Omics Research in Cerebral Palsy: Current Progress and Future Prospects. Neurochem Res 2022; 48:1269-1279. [PMID: 36512293 DOI: 10.1007/s11064-022-03839-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/10/2022] [Accepted: 11/29/2022] [Indexed: 12/15/2022]
Abstract
Cerebral palsy (CP) describes a heterogeneous group of non-progressive neurodevelopmental disorders affecting movement and posture. The etiology and diagnostic biomarkers of CP are a hot topic in clinical research. Recent advances in omics techniques, including genomics, epigenomics, transcriptomics, metabolomics and proteomics, have offered new insights to further understand the pathophysiology of CP and have allowed for identification of diagnostic biomarkers of CP. In present study, we reviewed the latest multi-omics investigations of CP and provided an in-depth summary of current research progress in CP. This review will offer the basis and recommendations for future fundamental research on the pathogenesis of CP, identification of diagnostic biomarkers, and prevention strategies for CP.
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Affiliation(s)
- Chengqi Xin
- Stem Cell Clinical Research Center, The First Affiliated Hospital of Dalian Medical University, No. 193, Lianhe Road, Shahekou District, 116011, Dalian City, Liaoning Province, P.R. China
- Dalian Innovation Institute of Stem Cell and Precision Medicine, No. 57, Xinda Street, Dalian High-Tech Park, 116023, Dalian City, Liaoning Province, P.R. China
| | - Xin Guan
- Stem Cell Clinical Research Center, The First Affiliated Hospital of Dalian Medical University, No. 193, Lianhe Road, Shahekou District, 116011, Dalian City, Liaoning Province, P.R. China
- Dalian Innovation Institute of Stem Cell and Precision Medicine, No. 57, Xinda Street, Dalian High-Tech Park, 116023, Dalian City, Liaoning Province, P.R. China
| | - Liang Wang
- Stem Cell Clinical Research Center, The First Affiliated Hospital of Dalian Medical University, No. 193, Lianhe Road, Shahekou District, 116011, Dalian City, Liaoning Province, P.R. China
- Dalian Innovation Institute of Stem Cell and Precision Medicine, No. 57, Xinda Street, Dalian High-Tech Park, 116023, Dalian City, Liaoning Province, P.R. China
| | - Jing Liu
- Stem Cell Clinical Research Center, The First Affiliated Hospital of Dalian Medical University, No. 193, Lianhe Road, Shahekou District, 116011, Dalian City, Liaoning Province, P.R. China.
- Dalian Innovation Institute of Stem Cell and Precision Medicine, No. 57, Xinda Street, Dalian High-Tech Park, 116023, Dalian City, Liaoning Province, P.R. China.
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7
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Sager G, Turkyilmaz A, Ates EA, Kutlubay B. HACE1, GLRX5, and ELP2 gene variant cause spastic paraplegies. Acta Neurol Belg 2022; 122:391-399. [PMID: 33813722 DOI: 10.1007/s13760-021-01649-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 03/08/2021] [Indexed: 10/21/2022]
Abstract
Hereditary spastic paraplegias (HSPs) are a clinically and genetically heterogeneous group of conditions that are characterized by lower limb spasticity and weakness. Considering the clinical overlap between metabolic causes, genetic diseases, and autosomal recessive HSP, differentiation between these types can be difficult based solely on their clinical characteristics. This study aimed to investigate the genetic etiology of patients with clinically suspected HSP. The study group was composed of seven Turkish families who each had two affected children and three families who each had a single affected child (17 total patients). The 17 probands (14 males, 3 females) underwent whole exome sequencing. Five typical HSP genes (FA2H, AP4M1, AP4E1, CYP7B1, and MAG) and three genes not previously related to HSP (HACE1, GLRX5, ad ELP2) were identified in 14 probands. Eight novel variants were identified in seven families: c.653 T > C (p.Leu218Pro) in the FA2H gene, c.347G > A (p.Gly116Asp) in the GLRX5 gene, c.2581G > C (p.Ala861Pro) in the HACE1 gene, c.1580G > A (p.Arg527Gln) and c.1189-1G > A in the ELP2 gene, c.10C > T (p.Gln4*) and c.1025 + 1G > A in the AP4M1 gene, c.1291delG (p.Gly431Alafs*3) and c.3250delA (p.Ile1084*) in the AP4E1 gene, and c.475 T > G (p.Cys159Gly) in the MAG gene. The growing use of next-generation sequencing improved diagnosis but also led to the continual identification of new causal genes for neurogenetic diseases associated with lower limb spasticity. The increasing number of HSP genes identified thus far highlights the extreme genetic heterogeneity of these disorders and their clinical and functional overlap with other neurological conditions. Our findings suggest that the HACE1, GLRX5, and ELP2 genes are genetic causes of HSP.
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Affiliation(s)
- Gunes Sager
- Department of Pediatric Neurology, Kartal Dr. Lutfi Kirdar City Hospital, Semsi Denizer Avenue, Cevizli, 34890, Kartal, Istanbul, Turkey.
| | - Ayberk Turkyilmaz
- Department of Medical Genetics, Erzurum City Hospital, Erzurum, Turkey
| | - Esra Arslan Ates
- Department of Medical Genetics, Marmara University Pendik Training and Research Hospital, Istanbul, Turkey
| | - Busra Kutlubay
- Department of Pediatric Neurology, Umraniye Training and Research Hospital, Istanbul, Turkey
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8
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Shin J, Nile A, Oh JW. Role of adaptin protein complexes in intracellular trafficking and their impact on diseases. Bioengineered 2021; 12:8259-8278. [PMID: 34565296 PMCID: PMC8806629 DOI: 10.1080/21655979.2021.1982846] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 09/15/2021] [Accepted: 09/15/2021] [Indexed: 02/07/2023] Open
Abstract
Adaptin proteins (APs) play a crucial role in intracellular cell trafficking. The 'classical' role of APs is carried out by AP1‒3, which bind to clathrin, cargo, and accessory proteins. Accordingly, AP1-3 are crucial for both vesicle formation and sorting. All APs consist of four subunits that are indispensable for their functions. In fact, based on studies using cells, model organism knockdown/knock-out, and human variants, each subunit plays crucial roles and contributes to the specificity of each AP. These studies also revealed that the sorting and intracellular trafficking function of AP can exert varying effects on pathology by controlling features such as cell development, signal transduction related to the apoptosis and proliferation pathways in cancer cells, organelle integrity, receptor presentation, and viral infection. Although the roles and functions of AP1‒3 are relatively well studied, the functions of the less abundant and more recently identified APs, AP4 and AP5, are still to be investigated. Further studies on these APs may enable a better understanding and targeting of specific diseases.APs known or suggested locations and functions.
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Affiliation(s)
- Juhyun Shin
- Department of Stem Cell and Regenerative Biotechnology and Animal Resources Research Center, Konkuk University, Seoul, Republic of Korea
| | - Arti Nile
- Department of Stem Cell and Regenerative Biotechnology and Animal Resources Research Center, Konkuk University, Seoul, Republic of Korea
| | - Jae-Wook Oh
- Department of Stem Cell and Regenerative Biotechnology and Animal Resources Research Center, Konkuk University, Seoul, Republic of Korea
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9
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A novel loss of function mutation in adaptor protein complex 4, subunit mu-1 causing autosomal recessive spastic paraplegia 50. Neurol Sci 2021; 42:5311-5319. [PMID: 33884525 DOI: 10.1007/s10072-021-05262-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 04/16/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Spastic paraplegia 50 (SPG50) is a rare autosomal recessive inherited disorder characterized by spasticity, severe intellectual disability and delayed or absent speech. Loss-of-function pathogenic mutations in the AP4M1 gene cause SPG50. METHODS In this study, we investigated the clinical and genetic characteristics of a consanguineous family with two male siblings who had infantile hypotonia that progressed to spasticity, paraplegia in one and quadriplegia in the other patient. In addition, the patients also exhibited neurodevelopmental phenotypes including severe intellectual disability, developmental delay, microcephaly and dysmorphism. RESULTS In order to identify the genetic cause, we performed cytogenetics, whole-exome sequencing and Sanger sequencing. Whole-exome sequencing of the affected siblings and unaffected parents revealed a novel exonic frameshift insertion of eight nucleotides (c.341_342insTGAAGTGC) on exon 4 of the AP4M1 gene. CONCLUSION Insertion of these eight nucleotides in the AP4M1 gene is predicted to result in a premature protein product of 132 amino acids. The truncated protein product lacks a signal binding domain which is essential for protein-protein interactions and the transport of cargo proteins to the membrane. Thus, the identified variant is pathogenic and our study expands the knowledge of clinical and genetic features of SPG50.
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10
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Lewis SA, Shetty S, Wilson BA, Huang AJ, Jin SC, Smithers-Sheedy H, Fahey MC, Kruer MC. Insights From Genetic Studies of Cerebral Palsy. Front Neurol 2021; 11:625428. [PMID: 33551980 PMCID: PMC7859255 DOI: 10.3389/fneur.2020.625428] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 12/16/2020] [Indexed: 12/11/2022] Open
Abstract
Cohort-based whole exome and whole genome sequencing and copy number variant (CNV) studies have identified genetic etiologies for a sizable proportion of patients with cerebral palsy (CP). These findings indicate that genetic mutations collectively comprise an important cause of CP. We review findings in CP genomics and propose criteria for CP-associated genes at the level of gene discovery, research study, and clinical application. We review the published literature and report 18 genes and 5 CNVs from genomics studies with strong evidence of for the pathophysiology of CP. CP-associated genes often disrupt early brain developmental programming or predispose individuals to known environmental risk factors. We discuss the overlap of CP-associated genes with other neurodevelopmental disorders and related movement disorders. We revisit diagnostic criteria for CP and discuss how identification of genetic etiologies does not preclude CP as an appropriate diagnosis. The identification of genetic etiologies improves our understanding of the neurobiology of CP, providing opportunities to study CP pathogenesis and develop mechanism-based interventions.
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Affiliation(s)
- Sara A Lewis
- Pediatric Movement Disorders Program, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, United States.,Departments of Child Health, Neurology, and Cellular & Molecular Medicine and Program in Genetics, University of Arizona College of Medicine, Phoenix, AZ, United States
| | - Sheetal Shetty
- Pediatric Movement Disorders Program, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, United States.,Departments of Child Health, Neurology, and Cellular & Molecular Medicine and Program in Genetics, University of Arizona College of Medicine, Phoenix, AZ, United States
| | - Bryce A Wilson
- Pediatric Movement Disorders Program, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, United States.,Departments of Child Health, Neurology, and Cellular & Molecular Medicine and Program in Genetics, University of Arizona College of Medicine, Phoenix, AZ, United States
| | - Aris J Huang
- Programs in Neuroscience and Molecular & Cellular Biology, School of Life Sciences, Arizona State University, Tempe, AZ, United States
| | - Sheng Chih Jin
- Department of Genetics, Washington University School of Medicine, St. Louis, MO, United States
| | - Hayley Smithers-Sheedy
- Cerebral Palsy Alliance, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia
| | - Michael C Fahey
- Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Michael C Kruer
- Pediatric Movement Disorders Program, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, United States.,Departments of Child Health, Neurology, and Cellular & Molecular Medicine and Program in Genetics, University of Arizona College of Medicine, Phoenix, AZ, United States.,Programs in Neuroscience and Molecular & Cellular Biology, School of Life Sciences, Arizona State University, Tempe, AZ, United States
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11
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The role of AP-4 in cargo export from the trans-Golgi network and hereditary spastic paraplegia. Biochem Soc Trans 2020; 48:1877-1888. [PMID: 33084855 DOI: 10.1042/bst20190664] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/22/2020] [Accepted: 09/29/2020] [Indexed: 01/02/2023]
Abstract
Heterotetrameric adaptor protein (AP) complexes play key roles in protein sorting and transport vesicle formation in the endomembrane system of eukaryotic cells. One of these complexes, AP-4, was identified over 20 years ago but, up until recently, its function remained unclear. AP-4 associates with the trans-Golgi network (TGN) through interaction with small GTPases of the ARF family and recognizes transmembrane proteins (i.e. cargos) having specific sorting signals in their cytosolic domains. Recent studies identified accessory proteins (tepsin, RUSC2 and the FHF complex) that co-operate with AP-4, and cargos (amyloid precursor protein, ATG9A and SERINC3/5) that are exported from the TGN in an AP-4-dependent manner. Defective export of ATG9A from the TGN in AP-4-deficient cells was shown to reduce ATG9A delivery to pre-autophagosomal structures, impairing autophagosome formation and/or maturation. In addition, mutations in AP-4-subunit genes were found to cause neurological dysfunction in mice and a form of complicated hereditary spastic paraplegia referred to as 'AP-4-deficiency syndrome' in humans. These findings demonstrated that mammalian AP-4 is required for the development and function of the central nervous system, possibly through its role in the sorting of ATG9A for the maintenance of autophagic homeostasis. In this article, we review the properties and functions of AP-4, and discuss how they might explain the clinical features of AP-4 deficiency.
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van Eyk CL, Corbett MA, Frank MSB, Webber DL, Newman M, Berry JG, Harper K, Haines BP, McMichael G, Woenig JA, MacLennan AH, Gecz J. Targeted resequencing identifies genes with recurrent variation in cerebral palsy. NPJ Genom Med 2019; 4:27. [PMID: 31700678 PMCID: PMC6828700 DOI: 10.1038/s41525-019-0101-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 09/17/2019] [Indexed: 01/13/2023] Open
Abstract
A growing body of evidence points to a considerable and heterogeneous genetic aetiology of cerebral palsy (CP). To identify recurrently variant CP genes, we designed a custom gene panel of 112 candidate genes. We tested 366 clinically unselected singleton cases with CP, including 271 cases not previously examined using next-generation sequencing technologies. Overall, 5.2% of the naïve cases (14/271) harboured a genetic variant of clinical significance in a known disease gene, with a further 4.8% of individuals (13/271) having a variant in a candidate gene classified as intolerant to variation. In the aggregate cohort of individuals from this study and our previous genomic investigations, six recurrently hit genes contributed at least 4% of disease burden to CP: COL4A1, TUBA1A, AGAP1, L1CAM, MAOB and KIF1A. Significance of Rare VAriants (SORVA) burden analysis identified four genes with a genome-wide significant burden of variants, AGAP1, ERLIN1, ZDHHC9 and PROC, of which we functionally assessed AGAP1 using a zebrafish model. Our investigations reinforce that CP is a heterogeneous neurodevelopmental disorder with known as well as novel genetic determinants.
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Affiliation(s)
- C L van Eyk
- 1Robinson Research Institute, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia.,2Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia
| | - M A Corbett
- 1Robinson Research Institute, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia.,2Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia
| | - M S B Frank
- 1Robinson Research Institute, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia.,2Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia
| | - D L Webber
- 1Robinson Research Institute, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia.,2Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia
| | - M Newman
- 3Alzheimer's Disease Genetics Laboratory, Centre for Molecular Pathology, School of Biological Sciences, University of Adelaide, Adelaide, SA Australia
| | - J G Berry
- 1Robinson Research Institute, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia.,2Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia
| | - K Harper
- 1Robinson Research Institute, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia.,2Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia
| | - B P Haines
- 1Robinson Research Institute, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia.,2Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia
| | - G McMichael
- 1Robinson Research Institute, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia.,2Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia
| | - J A Woenig
- 1Robinson Research Institute, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia.,2Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia
| | - A H MacLennan
- 1Robinson Research Institute, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia.,2Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia
| | - J Gecz
- 1Robinson Research Institute, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia.,2Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA Australia.,4South Australian Health and Medical Research Institute, Adelaide, SA Australia
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Hebbar M, Shukla A, Nampoothiri S, Bielas S, Girisha KM. Locus and allelic heterogeneity in five families with hereditary spastic paraplegia. J Hum Genet 2018; 64:17-21. [PMID: 30337681 PMCID: PMC6344291 DOI: 10.1038/s10038-018-0523-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 09/12/2018] [Accepted: 10/08/2018] [Indexed: 01/29/2023]
Abstract
Hereditary spastic paraplegias are a group of genetically heterogeneous neurological disorders characterized by progressive weakness and spasticity of lower limbs. We ascertained five families with eight individuals with hereditary spastic paraplegia. Pathogenic variants were identified by exome sequencing of index cases. The cohort consists of three families with spastic paraplegia type 47 (AP4B1) with a common mutation in two families, a family with spastic paraplegia type 50 (AP4M1), and two male siblings with X-linked spastic paraplegia 2 (PLP1). This work illustrates locus and allelic heterogeneity in five families with hereditary spastic paraplegia.
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Affiliation(s)
- Malavika Hebbar
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Anju Shukla
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Sheela Nampoothiri
- Department of Pediatric Genetics, Amrita Institute of Medical Sciences and Research Centre, Ponekkara, Cochin, Kerala, India
| | - Stephanie Bielas
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA
| | - Katta M Girisha
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India.
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Morgan C, Fahey M, Roy B, Novak I. Diagnosing cerebral palsy in full-term infants. J Paediatr Child Health 2018; 54:1159-1164. [PMID: 30294991 DOI: 10.1111/jpc.14177] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 07/18/2018] [Indexed: 12/25/2022]
Abstract
More than 50% of infants with cerebral palsy (CP) are born at or near term, with the vast majority having pre- or perinatally acquired CP. While some have a clinical history predictive of CP, such as neonatal encephalopathy or neonatal stroke, others have no readily identifiable risk factors. Paediatricians are often required to discriminate generalised motor delay from a variety of other diagnoses, including CP. This paper outlines known causal pathways to CP in term-born infants with a focus on differential diagnosis. Early and accurate diagnosis is important as it allows prompt access to early intervention during the critical periods of brain development. A combination of clinical history taking, standard clinical examination, neuroimaging and genetic testing should be started at the time of referral. Attention to the investigation of common comorbidities of CP, including feeding and sleep difficulties, and referral to early intervention are recommended.
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Affiliation(s)
- Catherine Morgan
- School of Medicine, Paediatrics and Child Health, Sydney, New South Wales, Australia
- Cerebral Palsy Alliance, School of Child and Adolescent Health, University of Sydney, Sydney, New South Wales, Australia
| | - Michael Fahey
- Department of Paediatrics, Monash University, Melbourne, Victoria, Australia
| | - Bithi Roy
- School of Medicine, Paediatrics and Child Health, Sydney, New South Wales, Australia
- School of Medicine, University of Notre Dame, Sydney, New South Wales, Australia
- Special Care Nursery, Mater Hospital Sydney, Sydney, New South Wales, Australia
| | - Iona Novak
- School of Medicine, Paediatrics and Child Health, Sydney, New South Wales, Australia
- Cerebral Palsy Alliance, School of Child and Adolescent Health, University of Sydney, Sydney, New South Wales, Australia
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15
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Analysis of 182 cerebral palsy transcriptomes points to dysregulation of trophic signalling pathways and overlap with autism. Transl Psychiatry 2018; 8:88. [PMID: 29681622 PMCID: PMC5911435 DOI: 10.1038/s41398-018-0136-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Accepted: 02/18/2018] [Indexed: 12/01/2022] Open
Abstract
Cerebral palsy (CP) is the most common motor disability of childhood. It is characterised by permanent, non-progressive but not unchanging problems with movement, posture and motor function, with a highly heterogeneous clinical spectrum and frequent neurodevelopmental comorbidities. The aetiology of CP is poorly understood, despite recent reports of a genetic contribution in some cases. Here we demonstrate transcriptional dysregulation of trophic signalling pathways in patient-derived cell lines from an unselected cohort of 182 CP-affected individuals using both differential expression analysis and weighted gene co-expression network analysis (WGCNA). We also show that genes differentially expressed in CP, as well as network modules significantly correlated with CP status, are enriched for genes associated with ASD. Combining transcriptome and whole exome sequencing (WES) data for this CP cohort likely resolves an additional 5% of cases separated to the 14% we have previously reported as resolved by WES. Collectively, these results support a convergent molecular abnormality in CP and ASD.
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Roubertie A, Hieu N, Roux CJ, Leboucq N, Manes G, Charif M, Echenne B, Goizet C, Guissart C, Meyer P, Marelli C, Rivier F, Burglen L, Horvath R, Hamel CP, Lenaers G. AP4 deficiency: A novel form of neurodegeneration with brain iron accumulation? NEUROLOGY-GENETICS 2018; 4:e217. [PMID: 29473051 PMCID: PMC5820597 DOI: 10.1212/nxg.0000000000000217] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Accepted: 12/10/2017] [Indexed: 11/15/2022]
Abstract
Objective To describe the clinico-radiological phenotype of 3 patients harboring a homozygous novel AP4M1 pathogenic mutation. Methods The 3 patients from an inbred family who exhibited early-onset developmental delay, tetraparesis, juvenile motor function deterioration, and intellectual deficiency were investigated by magnetic brain imaging using T1-weighted, T2-weighted, T2*-weighted, fluid-attenuated inversion recovery, susceptibility weighted imaging (SWI) sequences. Whole-exome sequencing was performed on the 3 patients. Results In the 3 patients, brain imaging identified the same pattern of bilateral SWI hyposignal of the globus pallidus, concordant with iron accumulation. A novel homozygous nonsense mutation was identified in AP4M1, segregating with the disease and leading to truncation of half of the adap domain of the protein. Conclusions Our results suggest that AP4M1 represents a new candidate gene that should be considered in the neurodegeneration with brain iron accumulation (NBIA) spectrum of disorders and highlight the intersections between hereditary spastic paraplegia and NBIA clinical presentations.
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Affiliation(s)
- Agathe Roubertie
- Département de Neuropédiatrie (A.R., B.E., P.M., F.R.), CHU Gui de Chauliac, Montpellier; Institut des Neurosciences de Montpellier (A.R., N.H., G.M., C.P.H.), INSERM U1051, Université de Montpellier; Service de Neuroradiologie (C.-J.R., N.L.), CHU Gui de Chauliac, Montpellier; Equipe MitoLab (M.C., G.L.), UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, France; Department of Medical Genetics (C. Goizet), Hopital Pellegrin, Bordeaux University Hospital; MRGM Laboratory (C. Goizet), INSERM U1211, University of Bordeaux; Laboratoire de Génétique Moléculaire (C. Guissart), CHU de Montpellier; U1046 INSERM (P.M., F.R.), UMR9214 CNRS, Université de Montpellier; Department of Neurology (C.M.), University Hospital Gui de Chauliac, Montpellier; Centre de Référence des Malformations et Maladies Congénitales du Cervelet (L.B.), Service de Génétique, Hôpital Armand Trousseau, AP-HP, Paris, France; Wellcome Trust Centre for Mitochondrial Research (R.H.), Institute of Genetic Medicine, Newcastle University, United Kingdom; and Centre of Reference for Genetic Sensory Diseases (C.P.H.), Montpellier, France
| | - Nelson Hieu
- Département de Neuropédiatrie (A.R., B.E., P.M., F.R.), CHU Gui de Chauliac, Montpellier; Institut des Neurosciences de Montpellier (A.R., N.H., G.M., C.P.H.), INSERM U1051, Université de Montpellier; Service de Neuroradiologie (C.-J.R., N.L.), CHU Gui de Chauliac, Montpellier; Equipe MitoLab (M.C., G.L.), UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, France; Department of Medical Genetics (C. Goizet), Hopital Pellegrin, Bordeaux University Hospital; MRGM Laboratory (C. Goizet), INSERM U1211, University of Bordeaux; Laboratoire de Génétique Moléculaire (C. Guissart), CHU de Montpellier; U1046 INSERM (P.M., F.R.), UMR9214 CNRS, Université de Montpellier; Department of Neurology (C.M.), University Hospital Gui de Chauliac, Montpellier; Centre de Référence des Malformations et Maladies Congénitales du Cervelet (L.B.), Service de Génétique, Hôpital Armand Trousseau, AP-HP, Paris, France; Wellcome Trust Centre for Mitochondrial Research (R.H.), Institute of Genetic Medicine, Newcastle University, United Kingdom; and Centre of Reference for Genetic Sensory Diseases (C.P.H.), Montpellier, France
| | - Charles-Joris Roux
- Département de Neuropédiatrie (A.R., B.E., P.M., F.R.), CHU Gui de Chauliac, Montpellier; Institut des Neurosciences de Montpellier (A.R., N.H., G.M., C.P.H.), INSERM U1051, Université de Montpellier; Service de Neuroradiologie (C.-J.R., N.L.), CHU Gui de Chauliac, Montpellier; Equipe MitoLab (M.C., G.L.), UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, France; Department of Medical Genetics (C. Goizet), Hopital Pellegrin, Bordeaux University Hospital; MRGM Laboratory (C. Goizet), INSERM U1211, University of Bordeaux; Laboratoire de Génétique Moléculaire (C. Guissart), CHU de Montpellier; U1046 INSERM (P.M., F.R.), UMR9214 CNRS, Université de Montpellier; Department of Neurology (C.M.), University Hospital Gui de Chauliac, Montpellier; Centre de Référence des Malformations et Maladies Congénitales du Cervelet (L.B.), Service de Génétique, Hôpital Armand Trousseau, AP-HP, Paris, France; Wellcome Trust Centre for Mitochondrial Research (R.H.), Institute of Genetic Medicine, Newcastle University, United Kingdom; and Centre of Reference for Genetic Sensory Diseases (C.P.H.), Montpellier, France
| | - Nicolas Leboucq
- Département de Neuropédiatrie (A.R., B.E., P.M., F.R.), CHU Gui de Chauliac, Montpellier; Institut des Neurosciences de Montpellier (A.R., N.H., G.M., C.P.H.), INSERM U1051, Université de Montpellier; Service de Neuroradiologie (C.-J.R., N.L.), CHU Gui de Chauliac, Montpellier; Equipe MitoLab (M.C., G.L.), UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, France; Department of Medical Genetics (C. Goizet), Hopital Pellegrin, Bordeaux University Hospital; MRGM Laboratory (C. Goizet), INSERM U1211, University of Bordeaux; Laboratoire de Génétique Moléculaire (C. Guissart), CHU de Montpellier; U1046 INSERM (P.M., F.R.), UMR9214 CNRS, Université de Montpellier; Department of Neurology (C.M.), University Hospital Gui de Chauliac, Montpellier; Centre de Référence des Malformations et Maladies Congénitales du Cervelet (L.B.), Service de Génétique, Hôpital Armand Trousseau, AP-HP, Paris, France; Wellcome Trust Centre for Mitochondrial Research (R.H.), Institute of Genetic Medicine, Newcastle University, United Kingdom; and Centre of Reference for Genetic Sensory Diseases (C.P.H.), Montpellier, France
| | - Gael Manes
- Département de Neuropédiatrie (A.R., B.E., P.M., F.R.), CHU Gui de Chauliac, Montpellier; Institut des Neurosciences de Montpellier (A.R., N.H., G.M., C.P.H.), INSERM U1051, Université de Montpellier; Service de Neuroradiologie (C.-J.R., N.L.), CHU Gui de Chauliac, Montpellier; Equipe MitoLab (M.C., G.L.), UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, France; Department of Medical Genetics (C. Goizet), Hopital Pellegrin, Bordeaux University Hospital; MRGM Laboratory (C. Goizet), INSERM U1211, University of Bordeaux; Laboratoire de Génétique Moléculaire (C. Guissart), CHU de Montpellier; U1046 INSERM (P.M., F.R.), UMR9214 CNRS, Université de Montpellier; Department of Neurology (C.M.), University Hospital Gui de Chauliac, Montpellier; Centre de Référence des Malformations et Maladies Congénitales du Cervelet (L.B.), Service de Génétique, Hôpital Armand Trousseau, AP-HP, Paris, France; Wellcome Trust Centre for Mitochondrial Research (R.H.), Institute of Genetic Medicine, Newcastle University, United Kingdom; and Centre of Reference for Genetic Sensory Diseases (C.P.H.), Montpellier, France
| | - Majida Charif
- Département de Neuropédiatrie (A.R., B.E., P.M., F.R.), CHU Gui de Chauliac, Montpellier; Institut des Neurosciences de Montpellier (A.R., N.H., G.M., C.P.H.), INSERM U1051, Université de Montpellier; Service de Neuroradiologie (C.-J.R., N.L.), CHU Gui de Chauliac, Montpellier; Equipe MitoLab (M.C., G.L.), UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, France; Department of Medical Genetics (C. Goizet), Hopital Pellegrin, Bordeaux University Hospital; MRGM Laboratory (C. Goizet), INSERM U1211, University of Bordeaux; Laboratoire de Génétique Moléculaire (C. Guissart), CHU de Montpellier; U1046 INSERM (P.M., F.R.), UMR9214 CNRS, Université de Montpellier; Department of Neurology (C.M.), University Hospital Gui de Chauliac, Montpellier; Centre de Référence des Malformations et Maladies Congénitales du Cervelet (L.B.), Service de Génétique, Hôpital Armand Trousseau, AP-HP, Paris, France; Wellcome Trust Centre for Mitochondrial Research (R.H.), Institute of Genetic Medicine, Newcastle University, United Kingdom; and Centre of Reference for Genetic Sensory Diseases (C.P.H.), Montpellier, France
| | - Bernard Echenne
- Département de Neuropédiatrie (A.R., B.E., P.M., F.R.), CHU Gui de Chauliac, Montpellier; Institut des Neurosciences de Montpellier (A.R., N.H., G.M., C.P.H.), INSERM U1051, Université de Montpellier; Service de Neuroradiologie (C.-J.R., N.L.), CHU Gui de Chauliac, Montpellier; Equipe MitoLab (M.C., G.L.), UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, France; Department of Medical Genetics (C. Goizet), Hopital Pellegrin, Bordeaux University Hospital; MRGM Laboratory (C. Goizet), INSERM U1211, University of Bordeaux; Laboratoire de Génétique Moléculaire (C. Guissart), CHU de Montpellier; U1046 INSERM (P.M., F.R.), UMR9214 CNRS, Université de Montpellier; Department of Neurology (C.M.), University Hospital Gui de Chauliac, Montpellier; Centre de Référence des Malformations et Maladies Congénitales du Cervelet (L.B.), Service de Génétique, Hôpital Armand Trousseau, AP-HP, Paris, France; Wellcome Trust Centre for Mitochondrial Research (R.H.), Institute of Genetic Medicine, Newcastle University, United Kingdom; and Centre of Reference for Genetic Sensory Diseases (C.P.H.), Montpellier, France
| | - Cyril Goizet
- Département de Neuropédiatrie (A.R., B.E., P.M., F.R.), CHU Gui de Chauliac, Montpellier; Institut des Neurosciences de Montpellier (A.R., N.H., G.M., C.P.H.), INSERM U1051, Université de Montpellier; Service de Neuroradiologie (C.-J.R., N.L.), CHU Gui de Chauliac, Montpellier; Equipe MitoLab (M.C., G.L.), UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, France; Department of Medical Genetics (C. Goizet), Hopital Pellegrin, Bordeaux University Hospital; MRGM Laboratory (C. Goizet), INSERM U1211, University of Bordeaux; Laboratoire de Génétique Moléculaire (C. Guissart), CHU de Montpellier; U1046 INSERM (P.M., F.R.), UMR9214 CNRS, Université de Montpellier; Department of Neurology (C.M.), University Hospital Gui de Chauliac, Montpellier; Centre de Référence des Malformations et Maladies Congénitales du Cervelet (L.B.), Service de Génétique, Hôpital Armand Trousseau, AP-HP, Paris, France; Wellcome Trust Centre for Mitochondrial Research (R.H.), Institute of Genetic Medicine, Newcastle University, United Kingdom; and Centre of Reference for Genetic Sensory Diseases (C.P.H.), Montpellier, France
| | - Claire Guissart
- Département de Neuropédiatrie (A.R., B.E., P.M., F.R.), CHU Gui de Chauliac, Montpellier; Institut des Neurosciences de Montpellier (A.R., N.H., G.M., C.P.H.), INSERM U1051, Université de Montpellier; Service de Neuroradiologie (C.-J.R., N.L.), CHU Gui de Chauliac, Montpellier; Equipe MitoLab (M.C., G.L.), UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, France; Department of Medical Genetics (C. Goizet), Hopital Pellegrin, Bordeaux University Hospital; MRGM Laboratory (C. Goizet), INSERM U1211, University of Bordeaux; Laboratoire de Génétique Moléculaire (C. Guissart), CHU de Montpellier; U1046 INSERM (P.M., F.R.), UMR9214 CNRS, Université de Montpellier; Department of Neurology (C.M.), University Hospital Gui de Chauliac, Montpellier; Centre de Référence des Malformations et Maladies Congénitales du Cervelet (L.B.), Service de Génétique, Hôpital Armand Trousseau, AP-HP, Paris, France; Wellcome Trust Centre for Mitochondrial Research (R.H.), Institute of Genetic Medicine, Newcastle University, United Kingdom; and Centre of Reference for Genetic Sensory Diseases (C.P.H.), Montpellier, France
| | - Pierre Meyer
- Département de Neuropédiatrie (A.R., B.E., P.M., F.R.), CHU Gui de Chauliac, Montpellier; Institut des Neurosciences de Montpellier (A.R., N.H., G.M., C.P.H.), INSERM U1051, Université de Montpellier; Service de Neuroradiologie (C.-J.R., N.L.), CHU Gui de Chauliac, Montpellier; Equipe MitoLab (M.C., G.L.), UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, France; Department of Medical Genetics (C. Goizet), Hopital Pellegrin, Bordeaux University Hospital; MRGM Laboratory (C. Goizet), INSERM U1211, University of Bordeaux; Laboratoire de Génétique Moléculaire (C. Guissart), CHU de Montpellier; U1046 INSERM (P.M., F.R.), UMR9214 CNRS, Université de Montpellier; Department of Neurology (C.M.), University Hospital Gui de Chauliac, Montpellier; Centre de Référence des Malformations et Maladies Congénitales du Cervelet (L.B.), Service de Génétique, Hôpital Armand Trousseau, AP-HP, Paris, France; Wellcome Trust Centre for Mitochondrial Research (R.H.), Institute of Genetic Medicine, Newcastle University, United Kingdom; and Centre of Reference for Genetic Sensory Diseases (C.P.H.), Montpellier, France
| | - Cecilia Marelli
- Département de Neuropédiatrie (A.R., B.E., P.M., F.R.), CHU Gui de Chauliac, Montpellier; Institut des Neurosciences de Montpellier (A.R., N.H., G.M., C.P.H.), INSERM U1051, Université de Montpellier; Service de Neuroradiologie (C.-J.R., N.L.), CHU Gui de Chauliac, Montpellier; Equipe MitoLab (M.C., G.L.), UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, France; Department of Medical Genetics (C. Goizet), Hopital Pellegrin, Bordeaux University Hospital; MRGM Laboratory (C. Goizet), INSERM U1211, University of Bordeaux; Laboratoire de Génétique Moléculaire (C. Guissart), CHU de Montpellier; U1046 INSERM (P.M., F.R.), UMR9214 CNRS, Université de Montpellier; Department of Neurology (C.M.), University Hospital Gui de Chauliac, Montpellier; Centre de Référence des Malformations et Maladies Congénitales du Cervelet (L.B.), Service de Génétique, Hôpital Armand Trousseau, AP-HP, Paris, France; Wellcome Trust Centre for Mitochondrial Research (R.H.), Institute of Genetic Medicine, Newcastle University, United Kingdom; and Centre of Reference for Genetic Sensory Diseases (C.P.H.), Montpellier, France
| | - François Rivier
- Département de Neuropédiatrie (A.R., B.E., P.M., F.R.), CHU Gui de Chauliac, Montpellier; Institut des Neurosciences de Montpellier (A.R., N.H., G.M., C.P.H.), INSERM U1051, Université de Montpellier; Service de Neuroradiologie (C.-J.R., N.L.), CHU Gui de Chauliac, Montpellier; Equipe MitoLab (M.C., G.L.), UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, France; Department of Medical Genetics (C. Goizet), Hopital Pellegrin, Bordeaux University Hospital; MRGM Laboratory (C. Goizet), INSERM U1211, University of Bordeaux; Laboratoire de Génétique Moléculaire (C. Guissart), CHU de Montpellier; U1046 INSERM (P.M., F.R.), UMR9214 CNRS, Université de Montpellier; Department of Neurology (C.M.), University Hospital Gui de Chauliac, Montpellier; Centre de Référence des Malformations et Maladies Congénitales du Cervelet (L.B.), Service de Génétique, Hôpital Armand Trousseau, AP-HP, Paris, France; Wellcome Trust Centre for Mitochondrial Research (R.H.), Institute of Genetic Medicine, Newcastle University, United Kingdom; and Centre of Reference for Genetic Sensory Diseases (C.P.H.), Montpellier, France
| | - Lydie Burglen
- Département de Neuropédiatrie (A.R., B.E., P.M., F.R.), CHU Gui de Chauliac, Montpellier; Institut des Neurosciences de Montpellier (A.R., N.H., G.M., C.P.H.), INSERM U1051, Université de Montpellier; Service de Neuroradiologie (C.-J.R., N.L.), CHU Gui de Chauliac, Montpellier; Equipe MitoLab (M.C., G.L.), UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, France; Department of Medical Genetics (C. Goizet), Hopital Pellegrin, Bordeaux University Hospital; MRGM Laboratory (C. Goizet), INSERM U1211, University of Bordeaux; Laboratoire de Génétique Moléculaire (C. Guissart), CHU de Montpellier; U1046 INSERM (P.M., F.R.), UMR9214 CNRS, Université de Montpellier; Department of Neurology (C.M.), University Hospital Gui de Chauliac, Montpellier; Centre de Référence des Malformations et Maladies Congénitales du Cervelet (L.B.), Service de Génétique, Hôpital Armand Trousseau, AP-HP, Paris, France; Wellcome Trust Centre for Mitochondrial Research (R.H.), Institute of Genetic Medicine, Newcastle University, United Kingdom; and Centre of Reference for Genetic Sensory Diseases (C.P.H.), Montpellier, France
| | - Rita Horvath
- Département de Neuropédiatrie (A.R., B.E., P.M., F.R.), CHU Gui de Chauliac, Montpellier; Institut des Neurosciences de Montpellier (A.R., N.H., G.M., C.P.H.), INSERM U1051, Université de Montpellier; Service de Neuroradiologie (C.-J.R., N.L.), CHU Gui de Chauliac, Montpellier; Equipe MitoLab (M.C., G.L.), UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, France; Department of Medical Genetics (C. Goizet), Hopital Pellegrin, Bordeaux University Hospital; MRGM Laboratory (C. Goizet), INSERM U1211, University of Bordeaux; Laboratoire de Génétique Moléculaire (C. Guissart), CHU de Montpellier; U1046 INSERM (P.M., F.R.), UMR9214 CNRS, Université de Montpellier; Department of Neurology (C.M.), University Hospital Gui de Chauliac, Montpellier; Centre de Référence des Malformations et Maladies Congénitales du Cervelet (L.B.), Service de Génétique, Hôpital Armand Trousseau, AP-HP, Paris, France; Wellcome Trust Centre for Mitochondrial Research (R.H.), Institute of Genetic Medicine, Newcastle University, United Kingdom; and Centre of Reference for Genetic Sensory Diseases (C.P.H.), Montpellier, France
| | - Christian P Hamel
- Département de Neuropédiatrie (A.R., B.E., P.M., F.R.), CHU Gui de Chauliac, Montpellier; Institut des Neurosciences de Montpellier (A.R., N.H., G.M., C.P.H.), INSERM U1051, Université de Montpellier; Service de Neuroradiologie (C.-J.R., N.L.), CHU Gui de Chauliac, Montpellier; Equipe MitoLab (M.C., G.L.), UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, France; Department of Medical Genetics (C. Goizet), Hopital Pellegrin, Bordeaux University Hospital; MRGM Laboratory (C. Goizet), INSERM U1211, University of Bordeaux; Laboratoire de Génétique Moléculaire (C. Guissart), CHU de Montpellier; U1046 INSERM (P.M., F.R.), UMR9214 CNRS, Université de Montpellier; Department of Neurology (C.M.), University Hospital Gui de Chauliac, Montpellier; Centre de Référence des Malformations et Maladies Congénitales du Cervelet (L.B.), Service de Génétique, Hôpital Armand Trousseau, AP-HP, Paris, France; Wellcome Trust Centre for Mitochondrial Research (R.H.), Institute of Genetic Medicine, Newcastle University, United Kingdom; and Centre of Reference for Genetic Sensory Diseases (C.P.H.), Montpellier, France
| | - Guy Lenaers
- Département de Neuropédiatrie (A.R., B.E., P.M., F.R.), CHU Gui de Chauliac, Montpellier; Institut des Neurosciences de Montpellier (A.R., N.H., G.M., C.P.H.), INSERM U1051, Université de Montpellier; Service de Neuroradiologie (C.-J.R., N.L.), CHU Gui de Chauliac, Montpellier; Equipe MitoLab (M.C., G.L.), UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, France; Department of Medical Genetics (C. Goizet), Hopital Pellegrin, Bordeaux University Hospital; MRGM Laboratory (C. Goizet), INSERM U1211, University of Bordeaux; Laboratoire de Génétique Moléculaire (C. Guissart), CHU de Montpellier; U1046 INSERM (P.M., F.R.), UMR9214 CNRS, Université de Montpellier; Department of Neurology (C.M.), University Hospital Gui de Chauliac, Montpellier; Centre de Référence des Malformations et Maladies Congénitales du Cervelet (L.B.), Service de Génétique, Hôpital Armand Trousseau, AP-HP, Paris, France; Wellcome Trust Centre for Mitochondrial Research (R.H.), Institute of Genetic Medicine, Newcastle University, United Kingdom; and Centre of Reference for Genetic Sensory Diseases (C.P.H.), Montpellier, France
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van Eyk C, Corbett M, Maclennan A. The emerging genetic landscape of cerebral palsy. HANDBOOK OF CLINICAL NEUROLOGY 2018; 147:331-342. [DOI: 10.1016/b978-0-444-63233-3.00022-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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18
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Ebrahimi-Fakhari D, Cheng C, Dies K, Diplock A, Pier DB, Ryan CS, Lanpher BC, Hirst J, Chung WK, Sahin M, Rosser E, Darras B, Bennett JT. Clinical and genetic characterization of AP4B1-associated SPG47. Am J Med Genet A 2017; 176:311-318. [PMID: 29193663 DOI: 10.1002/ajmg.a.38561] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 11/05/2017] [Accepted: 11/07/2017] [Indexed: 11/12/2022]
Abstract
The hereditary spastic paraplegias (HSPs) are a heterogeneous group of disorders characterized by degeneration of the corticospinal and spinocerebellar tracts leading to progressive spasticity. One subtype, spastic paraplegia type 47 (SPG47 or HSP-AP4B1), is due to bi-allelic loss-of-function mutations in the AP4B1 gene. AP4B1 is a subunit of the adapter protein complex 4 (AP-4), a heterotetrameric protein complex that regulates the transport of membrane proteins. Since 2011, 11 individuals from six families with AP4B1 mutations have been reported, nine of whom had homozygous mutations and were from consanguineous families. Here we report eight patients with AP4B1-associated SPG47, the majority born to non-consanguineous parents and carrying compound heterozygous mutations. Core clinical features in this cohort and previously published patients include neonatal hypotonia that progresses to spasticity, early onset developmental delay with prominent motor delay and severely impaired or absent speech development, episodes of stereotypic laughter, seizures including frequent febrile seizures, thinning of the corpus callosum, and delayed myelination/white matter loss. Given that some of the features of AP-4 deficiency overlap with those of cerebral palsy, and the discovery of the disorder in non-consanguineous populations, we believe that AP-4 deficiency may be more common than previously appreciated.
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Affiliation(s)
- Darius Ebrahimi-Fakhari
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.,Division of General Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Chi Cheng
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington
| | - Kira Dies
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Amelia Diplock
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Danielle B Pier
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.,Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts
| | - Conor S Ryan
- Department of Child and Adolescent Neurology, Mayo Clinic, Rochester, Minnesota
| | | | - Jennifer Hirst
- Cambridge Institute for Medical Research, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
| | - Wendy K Chung
- Department of Pediatrics and Medicine, Columbia University Medical Center, New York, New York
| | - Mustafa Sahin
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Elisabeth Rosser
- Department of Clinical Genetics, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Basil Darras
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - James T Bennett
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, and Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, Washington
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19
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Bettencourt C, Salpietro V, Efthymiou S, Chelban V, Hughes D, Pittman AM, Federoff M, Bourinaris T, Spilioti M, Deretzi G, Kalantzakou T, Houlden H, Singleton AB, Xiromerisiou G. Genotype-phenotype correlations and expansion of the molecular spectrum of AP4M1-related hereditary spastic paraplegia. Orphanet J Rare Dis 2017; 12:172. [PMID: 29096665 PMCID: PMC5669016 DOI: 10.1186/s13023-017-0721-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 10/25/2017] [Indexed: 11/28/2022] Open
Abstract
Background Autosomal recessive hereditary spastic paraplegia (HSP) due to AP4M1 mutations is a very rare neurodevelopmental disorder reported for only a few patients. Methods We investigated a Greek HSP family using whole exome sequencing (WES). Results A novel AP4M1A frameshift insertion, and a very rare missense variant were identified in all three affected siblings in the compound heterozygous state (p.V174fs and p.C319R); the unaffected parents were carriers of only one variant. Patients were affected with a combination of: (a) febrile seizures with onset in the first year of life (followed by epileptic non-febrile seizures); (b) distinctive facial appearance (e.g., coarse features, bulbous nose and hypomimia); (c) developmental delay and intellectual disability; (d) early-onset spastic weakness of the lower limbs; and (e) cerebellar hypoplasia/atrophy on brain MRI. Conclusions We review genotype-phenotype correlations and discuss clinical overlaps between different AP4-related diseases. The AP4M1 belongs to a complex that mediates vesicle trafficking of glutamate receptors, being likely involved in brain development and neurotransmission. Electronic supplementary material The online version of this article (10.1186/s13023-017-0721-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Conceição Bettencourt
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London, WC1N 3BG, UK. .,Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, WC1N 3BG, UK.
| | - Vincenzo Salpietro
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London, WC1N 3BG, UK.
| | - Stephanie Efthymiou
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London, WC1N 3BG, UK.,Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Viorica Chelban
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London, WC1N 3BG, UK.,Department of Neurology, Medical State University N, Testemitanu, Chisinau, Moldova
| | - Deborah Hughes
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Alan M Pittman
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Monica Federoff
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London, WC1N 3BG, UK.,Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Thomas Bourinaris
- Department of Neurology, Papageorgiou Hospital, Thessaloniki, Greece
| | - Martha Spilioti
- Neurology Department of Aristotle University of Thessaloniki, AHEPA University Hospital, Thessaloniki, Greece
| | - Georgia Deretzi
- Department of Neurology, Papageorgiou Hospital, Thessaloniki, Greece
| | | | - Henry Houlden
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London, WC1N 3BG, UK. .,National Hospital for Neurology and Neurosurgery, University College London Hospitals, London, WC1N 3BG, UK.
| | - Andrew B Singleton
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD, 20892, USA
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20
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Duerinckx S, Verhelst H, Perazzolo C, David P, Desmyter L, Pirson I, Abramowicz M. Severe congenital microcephaly with AP4M1 mutation, a case report. BMC MEDICAL GENETICS 2017; 18:48. [PMID: 28464862 PMCID: PMC5414176 DOI: 10.1186/s12881-017-0412-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 04/20/2017] [Indexed: 12/30/2022]
Abstract
Background Autosomal recessive defects of either the B1, E1, M1 or S1 subunit of the Adaptor Protein complex-4 (AP4) are characterized by developmental delay, severe intellectual disability, spasticity, and occasionally mild to moderate microcephaly of essentially postnatal onset. Case presentation We report on a patient with severe microcephaly of prenatal onset, and progressive spasticity, developmental delay, and severe intellectual deficiency. Exome sequencing showed a homozygous mutation in AP4M1, causing the replacement of an arginine by a stop codon at position 338 of the protein (p.Arg338X). The premature stop codon truncates the Mu homology domain of AP4M1, with predicted loss of function. Exome analysis also showed heterozygous variants in three genes, ATR, MCPH1 and BLM, which are known causes of autosomal recessive primary microcephaly. Conclusions Our findings expand the AP4M1 phenotype to severe microcephaly of prenatal onset, and more generally suggest that the AP4 defect might share mechanisms of prenatal neuronal depletion with other genetic defects of brain development causing congenital, primary microcephaly. Electronic supplementary material The online version of this article (doi:10.1186/s12881-017-0412-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Helene Verhelst
- Department of Paediatric Neurology, Ghent University Hospital, Ghent, Belgium
| | | | - Philippe David
- Department of Medical Imaging and Radiology, Hôpital Erasme - Université Libre de Bruxelles, Brussels, Belgium
| | - Laurence Desmyter
- Department of Medical Genetics, Hôpital Erasme - Université Libre de Bruxelles, Brussels, Belgium
| | | | - Marc Abramowicz
- IRIBHM, Université Libre de Bruxelles, Brussels, Belgium. .,Department of Medical Genetics, Hôpital Erasme - Université Libre de Bruxelles, Brussels, Belgium.
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21
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Assoum M, Philippe C, Isidor B, Perrin L, Makrythanasis P, Sondheimer N, Paris C, Douglas J, Lesca G, Antonarakis S, Hamamy H, Jouan T, Duffourd Y, Auvin S, Saunier A, Begtrup A, Nowak C, Chatron N, Ville D, Mireskandari K, Milani P, Jonveaux P, Lemeur G, Milh M, Amamoto M, Kato M, Nakashima M, Miyake N, Matsumoto N, Masri A, Thauvin-Robinet C, Rivière JB, Faivre L, Thevenon J. Autosomal-Recessive Mutations in AP3B2, Adaptor-Related Protein Complex 3 Beta 2 Subunit, Cause an Early-Onset Epileptic Encephalopathy with Optic Atrophy. Am J Hum Genet 2016; 99:1368-1376. [PMID: 27889060 DOI: 10.1016/j.ajhg.2016.10.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 10/14/2016] [Accepted: 10/14/2016] [Indexed: 11/30/2022] Open
Abstract
Early-onset epileptic encephalopathy (EOEE) represents a heterogeneous group of severe disorders characterized by seizures, interictal epileptiform activity with a disorganized electroencephalography background, developmental regression or retardation, and onset before 1 year of age. Among a cohort of 57 individuals with epileptic encephalopathy, we ascertained two unrelated affected individuals with EOEE associated with developmental impairment and autosomal-recessive variants in AP3B2 by means of whole-exome sequencing. The targeted sequencing of AP3B2 in 86 unrelated individuals with EOEE led to the identification of an additional family. We gathered five additional families with eight affected individuals through the Matchmaker Exchange initiative by matching autosomal-recessive mutations in AP3B2. Reverse phenotyping of 12 affected individuals from eight families revealed a homogeneous EOEE phenotype characterized by severe developmental delay, poor visual contact with optic atrophy, and postnatal microcephaly. No spasticity, albinism, or hematological symptoms were reported. AP3B2 encodes the neuron-specific subunit of the AP-3 complex. Autosomal-recessive variations of AP3B1, the ubiquitous isoform, cause Hermansky-Pudlak syndrome type 2. The only isoform for the δ subunit of the AP-3 complex is encoded by AP3D1. Autosomal-recessive mutations in AP3D1 cause a severe disorder cumulating the symptoms of the AP3B1 and AP3B2 defects.
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Affiliation(s)
- Mirna Assoum
- Equipe d'Accueil 4271, Génétique des Anomalies du Développement, Université de Bourgogne, 21079 Dijon, France
| | - Christophe Philippe
- Laboratoire de Génétique Médicale, INSERM U954 (Nutrition-Genetics-Environmental Risk Exposure), Centre Hospitalier Universaire Hôpitaux de Brabois, 54511 Vandoeuvre les Nancy, France
| | - Bertrand Isidor
- Service de Génétique Médicale, Centre Hospitalier Universaire de Nantes, 44093 Nantes, France; INSERM UMR_S957, 44093 Nantes, France
| | - Laurence Perrin
- Département de Génétique, Centre Hospitalier Universaire Paris - Hôpital Robert Debré, Assistance Publique - Hôpitaux de Paris, 75019 Paris, France
| | - Periklis Makrythanasis
- Department of Genetic Medicine and Development, University of Geneva, Rue Michel-Servet 1, 1211 Geneva 4, Switzerland; Service of Genetic Medicine, University Hospitals of Geneva, 1211 Geneva 4, Switzerland
| | - Neal Sondheimer
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada
| | - Caroline Paris
- Centre Hospitalier Régional Universitaire, Hôpital Jean Minjoz, 25030 Besançon, France
| | - Jessica Douglas
- Boston Children's Hospital, Feingold Center, Boston, MA 02115, USA
| | - Gaetan Lesca
- Department of Medical Genetics, Groupement Hospitalier Est, Hospices Civils de Lyon, 69677 Bron, France; Université de Lyon, 69100 Villeurbanne, France; Centre Nationnal de la Recherche Scientifique UMR 5292, INSERM U1028, Centre de Recherche en Neurosciences de Lyon, bâtiment l'Institut Multidisciplinaire de Biochimie des Lipides, 69621 Villeurbanne, France
| | - Stylianos Antonarakis
- Department of Genetic Medicine and Development, University of Geneva, Rue Michel-Servet 1, 1211 Geneva 4, Switzerland; Service of Genetic Medicine, University Hospitals of Geneva, 1211 Geneva 4, Switzerland; Institute of Genetics and Genomics of Geneva, University of Geneva, 1211 Geneva 4, Switzerland
| | - Hanan Hamamy
- Department of Genetic Medicine and Development, University of Geneva, Rue Michel-Servet 1, 1211 Geneva 4, Switzerland
| | - Thibaud Jouan
- Equipe d'Accueil 4271, Génétique des Anomalies du Développement, Université de Bourgogne, 21079 Dijon, France
| | - Yannis Duffourd
- Equipe d'Accueil 4271, Génétique des Anomalies du Développement, Université de Bourgogne, 21079 Dijon, France; Fédération Hospitalo-Universitaire Médecine Translationnelle et Anomalies du Développement, Centre Hospitalier Universitaire Dijon, 21079 Dijon, France
| | - Stéphane Auvin
- INSERM 1141, Service de Neurologie Pédiatrique, Hôpital Robert Debré, 75019 Paris, France
| | - Aline Saunier
- Laboratoire de Génétique Médicale, INSERM U954 (Nutrition-Genetics-Environmental Risk Exposure), Centre Hospitalier Universaire Hôpitaux de Brabois, 54511 Vandoeuvre les Nancy, France
| | - Amber Begtrup
- GeneDx, 207 Perry Parkway, Gaithersburg, MD 20877, USA
| | - Catherine Nowak
- Boston Children's Hospital, Feingold Center, Boston, MA 02115, USA
| | - Nicolas Chatron
- Department of Medical Genetics, Groupement Hospitalier Est, Hospices Civils de Lyon, 69677 Bron, France; Université de Lyon, 69100 Villeurbanne, France; Centre Nationnal de la Recherche Scientifique UMR 5292, INSERM U1028, Centre de Recherche en Neurosciences de Lyon, bâtiment l'Institut Multidisciplinaire de Biochimie des Lipides, 69621 Villeurbanne, France
| | - Dorothée Ville
- Department of Pediatric Neurology, Groupement Hospitalier Est, Hospices Civils de Lyon, 69677 Bron, France
| | - Kamiar Mireskandari
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada
| | - Paolo Milani
- Service de Physiologie Clinique et Explorations Fonctionnelles, Hôpital Lariboisière, Assistance Publique - Hôpitaux de Paris, 75475 Paris, France
| | - Philippe Jonveaux
- Laboratoire de Génétique Médicale, INSERM U954 (Nutrition-Genetics-Environmental Risk Exposure), Centre Hospitalier Universaire Hôpitaux de Brabois, 54511 Vandoeuvre les Nancy, France
| | - Guylène Lemeur
- Service d'Ophtalmologie, Centre Hospitalo-Universitaire de Nantes, 44093 Nantes, France
| | - Mathieu Milh
- Service de Neurologie Pédiatrique, Hôpital de la Timone, Assistance Publique des Hôpitaux de Marseille, 13005 Marseille, France; INSERM UMR_S910, Aix-Marseille Université, 13005 Marseille, France
| | - Masano Amamoto
- Pediatrics Emergency Center, Kitakyushu Municipal Yahata Hospitals, Kitakyushu 803-8501, Japan
| | - Mitsuhiro Kato
- Department of Pediatrics, Showa University School of Medicine, Tokyo 142-8555, Japan
| | - Mitsuko Nakashima
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Noriko Miyake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
| | - Amira Masri
- Department of Paediatrics, Faculty of Medicine, Jordan University, Amman 11942, Jordan
| | - Christel Thauvin-Robinet
- Equipe d'Accueil 4271, Génétique des Anomalies du Développement, Université de Bourgogne, 21079 Dijon, France; INSERM 1141, Service de Neurologie Pédiatrique, Hôpital Robert Debré, 75019 Paris, France; Centre de Génétique et Centre de Référence Anomalies du Développement et Syndromes Malformatifs de l'Interrégion Est, Centre Hospitalier Universitaire Dijon, 21079 Dijon, France
| | - Jean-Baptiste Rivière
- Equipe d'Accueil 4271, Génétique des Anomalies du Développement, Université de Bourgogne, 21079 Dijon, France; INSERM 1141, Service de Neurologie Pédiatrique, Hôpital Robert Debré, 75019 Paris, France
| | - Laurence Faivre
- Equipe d'Accueil 4271, Génétique des Anomalies du Développement, Université de Bourgogne, 21079 Dijon, France; INSERM 1141, Service de Neurologie Pédiatrique, Hôpital Robert Debré, 75019 Paris, France; Centre de Génétique et Centre de Référence Anomalies du Développement et Syndromes Malformatifs de l'Interrégion Est, Centre Hospitalier Universitaire Dijon, 21079 Dijon, France
| | - Julien Thevenon
- Equipe d'Accueil 4271, Génétique des Anomalies du Développement, Université de Bourgogne, 21079 Dijon, France; INSERM 1141, Service de Neurologie Pédiatrique, Hôpital Robert Debré, 75019 Paris, France; Centre de Génétique et Centre de Référence Anomalies du Développement et Syndromes Malformatifs de l'Interrégion Est, Centre Hospitalier Universitaire Dijon, 21079 Dijon, France.
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22
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Hardies K, May P, Djémié T, Tarta-Arsene O, Deconinck T, Craiu D, Helbig I, Suls A, Balling R, Weckhuysen S, De Jonghe P, Hirst J. Recessive loss-of-function mutations in AP4S1 cause mild fever-sensitive seizures, developmental delay and spastic paraplegia through loss of AP-4 complex assembly. Hum Mol Genet 2014; 24:2218-27. [PMID: 25552650 DOI: 10.1093/hmg/ddu740] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We report two siblings with infantile onset seizures, severe developmental delay and spastic paraplegia, in whom whole-genome sequencing revealed compound heterozygous mutations in the AP4S1 gene, encoding the σ subunit of the adaptor protein complex 4 (AP-4). The effect of the predicted loss-of-function variants (p.Gln46Profs*9 and p.Arg97*) was further investigated in a patient's fibroblast cell line. We show that the premature stop mutations in AP4S1 result in a reduction of all AP-4 subunits and loss of AP-4 complex assembly. Recruitment of the AP-4 accessory protein tepsin, to the membrane was also abolished. In retrospect, the clinical phenotype in the family is consistent with previous reports of the AP-4 deficiency syndrome. Our study reports the second family with mutations in AP4S1 and describes the first two patients with loss of AP4S1 and seizures. We further discuss seizure phenotypes in reported patients, highlighting that seizures are part of the clinical manifestation of the AP-4 deficiency syndrome. We also hypothesize that endosomal trafficking is a common theme between heritable spastic paraplegia and some inherited epilepsies.
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Affiliation(s)
- Katia Hardies
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium, Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Patrick May
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg, Institute for Systems Biology, Seattle, USA
| | - Tania Djémié
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium, Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Oana Tarta-Arsene
- Pediatric Neurology Clinic, Al Obregia Hospital, Bucharest, Romania, Department of Neurology, Pediatric Neurology, Psychiatry, Child and Adolescent Psychiatry, and Neurosurgery, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Tine Deconinck
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium, Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Dana Craiu
- Pediatric Neurology Clinic, Al Obregia Hospital, Bucharest, Romania, Department of Neurology, Pediatric Neurology, Psychiatry, Child and Adolescent Psychiatry, and Neurosurgery, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | | | - Ingo Helbig
- Department of Neuropediatrics, University Medical Center Schleswig-Holstein, Christian Albrechts University, Kiel, Germany, Division of Neurology, The Children's Hospital of Philadelphia, Philadephia, USA
| | - Arvid Suls
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium, Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Rudy Balling
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Sarah Weckhuysen
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium, Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Peter De Jonghe
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium, Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium, Division of Neurology, Antwerp University Hospital, Antwerp, Belgium and
| | - Jennifer Hirst
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
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