1
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Fang L, Wang L, Yang L, Xu X, Pei S, Wu D. Novel variants identified in five Chinese families with Joubert Syndrome: a case report. BMC Med Genomics 2023; 16:221. [PMID: 37735380 PMCID: PMC10512497 DOI: 10.1186/s12920-023-01669-7] [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: 01/17/2023] [Accepted: 09/20/2023] [Indexed: 09/23/2023] Open
Abstract
BACKGROUND Joubert syndrome (JS) is a group of rare ciliopathies, mainly characterized by cerebellar dysplasia representing the "molar tooth sign (MTS)" on neuroimaging, hypotonia, and developmental delay. Having a complicated genotype-phenotype correlation due to its rich genetic heterogeneity, JS is usually combined with other organic defects affecting the retina, kidney, and liver. This report aimed to present new cases and novel variants of JS. CASE PRESENTATION Five unrelated patients who were diagnosed with JS, with or without typical clinical characteristics, received integrated examinations, including whole-exome sequencing (WES) and Sanger sequencing. We identified nine pathogenic variants in the TCTN2, CPLANE1, INPP5E, NPHP1, and CC2D2A genes. CONCLUSION Four novel pathogenic mutations in the TCTN2, CPLANE1, and INPP5E genes were reported. The findings broadened the genotypic spectrum of JS and contributed to a better understanding of genotype-phenotype correlation.
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Affiliation(s)
- Liwei Fang
- Pediatric Neurorehabilitation Center, Pediatric Department, The First Affiliated Hospital of Anhui Medical University, Hefei, 230000, China
| | - Lulu Wang
- Pediatric Neurorehabilitation Center, Pediatric Department, The First Affiliated Hospital of Anhui Medical University, Hefei, 230000, China
| | - Li Yang
- Pediatric Neurorehabilitation Center, Pediatric Department, The First Affiliated Hospital of Anhui Medical University, Hefei, 230000, China
| | - Xiaoyan Xu
- Pediatric Neurorehabilitation Center, Pediatric Department, The First Affiliated Hospital of Anhui Medical University, Hefei, 230000, China
| | - Shanai Pei
- Pediatric Neurorehabilitation Center, Pediatric Department, The First Affiliated Hospital of Anhui Medical University, Hefei, 230000, China
| | - De Wu
- Pediatric Neurorehabilitation Center, Pediatric Department, The First Affiliated Hospital of Anhui Medical University, Hefei, 230000, China.
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2
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Truong HM, Cruz-Colón KO, Martínez-Márquez JY, Willer JR, Travis AM, Biswas SK, Lo WK, Bolz HJ, Pearring JN. The tectonic complex regulates membrane protein composition in the photoreceptor cilium. Nat Commun 2023; 14:5671. [PMID: 37704658 PMCID: PMC10500017 DOI: 10.1038/s41467-023-41450-z] [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: 11/01/2022] [Accepted: 08/30/2023] [Indexed: 09/15/2023] Open
Abstract
The primary cilium is a signaling organelle with a unique membrane composition maintained by a diffusional barrier residing at the transition zone. Many transition zone proteins, such as the tectonic complex, are linked to preserving ciliary composition but the mechanism remains unknown. To understand tectonic's role, we generate a photoreceptor-specific Tctn1 knockout mouse. Loss of Tctn1 results in the absence of the entire tectonic complex and associated MKS proteins yet has minimal effects on the transition zone structure of rod photoreceptors. We find that the protein composition of the photoreceptor cilium is disrupted as non-resident membrane proteins accumulate in the cilium over time, ultimately resulting in photoreceptor degeneration. We further show that fluorescent rhodopsin moves faster through the transition zone in photoreceptors lacking tectonic, which suggests that the tectonic complex acts as a physical barrier to slow down membrane protein diffusion in the photoreceptor transition zone to ensure proper removal of non-resident membrane proteins.
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Affiliation(s)
- Hanh M Truong
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, USA
| | - Kevin O Cruz-Colón
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA
| | | | - Jason R Willer
- Department of Ophthalmology and Visual Science, University of Michigan, Ann Arbor, MI, USA
| | - Amanda M Travis
- Department of Ophthalmology and Visual Science, University of Michigan, Ann Arbor, MI, USA
| | - Sondip K Biswas
- Department of Neurobiology, Morehouse School of Medicine, Atlanta, GA, USA
| | - Woo-Kuen Lo
- Department of Neurobiology, Morehouse School of Medicine, Atlanta, GA, USA
| | - Hanno J Bolz
- Senckenberg Centre for Human Genetics, Frankfurt am Main, Germany
- Institute of Human Genetics, University Hospital of Cologne, Cologne, Germany
| | - Jillian N Pearring
- Department of Ophthalmology and Visual Science, University of Michigan, Ann Arbor, MI, USA.
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.
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3
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A deep intronic TCTN2 variant activating a cryptic exon predicted by SpliceRover in a patient with Joubert syndrome. J Hum Genet 2023:10.1038/s10038-023-01143-3. [PMID: 36894704 DOI: 10.1038/s10038-023-01143-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 01/26/2023] [Accepted: 02/27/2023] [Indexed: 03/11/2023]
Abstract
The recent introduction of genome sequencing in genetic analysis has led to the identification of pathogenic variants located in deep introns. Recently, several new tools have emerged to predict the impact of variants on splicing. Here, we present a Japanese boy of Joubert syndrome with biallelic TCTN2 variants. Exome sequencing identified only a heterozygous maternal nonsense TCTN2 variant (NM_024809.5:c.916C >T, p.(Gln306Ter)). Subsequent genome sequencing identified a deep intronic variant (c.1033+423G>A) inherited from his father. The machine learning algorithms SpliceAI, Squirls, and Pangolin were unable to predict alterations in splicing by the c.1033+423G>A variant. SpliceRover, a tool for splice site prediction using FASTA sequence, was able to detect a cryptic exon which was 85-bp away from the variant and within the inverted Alu sequence while SpliceRover scores for these splice sites showed slight increase (donor) or decrease (acceptor) between the reference and mutant sequences. RNA sequencing and RT-PCR using urinary cells confirmed inclusion of the cryptic exon. The patient showed major symptoms of TCTN2-related disorders such as developmental delay, dysmorphic facial features and polydactyly. He also showed uncommon features such as retinal dystrophy, exotropia, abnormal pattern of respiration, and periventricular heterotopia, confirming these as one of features of TCTN2-related disorders. Our study highlights usefulness of genome sequencing and RNA sequencing using urinary cells for molecular diagnosis of genetic disorders and suggests that database of cryptic splice sites predicted in introns by SpliceRover using the reference sequences can be helpful in extracting candidate variants from large numbers of intronic variants in genome sequencing.
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Wang H, Nie W, Wang C, Wang Z, Zheng Y. Novel CPLANE1 c.8948dupT (p.P2984Tfs*7) variant in a child patient with Joubert syndrome. Open Life Sci 2023; 18:20220542. [PMID: 36789003 PMCID: PMC9896164 DOI: 10.1515/biol-2022-0542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 10/20/2022] [Accepted: 11/23/2022] [Indexed: 02/04/2023] Open
Abstract
Joubert syndrome (JBTS) is a class of heterogeneous ciliopathy genetically associated with CPLANE1 mutations. The characteristics of clinical phenotypes and CPLANE1 variants were analyzed in a 2-month-old patient. A 2-month-old patient with JBTS was diagnosed after clinical evaluation including family history, physical examination, cerebral MRI, ultrasonography imaging, VEGG, ocular fundus examination, and comprehensive blood and urine testing. Whole exome sequencing (WES) was performed to detect CPLANE1 variants, and Sanger sequencing was used to confirm the variants. This JBTS patient presented with oculomotor apraxia, dysregulation of breathing pattern, and ataxia. MRI revealed poor continuity of cerebelli, batwing appearance, and molar tooth sign. This patient was noted with abnormal hematology, dysregulation of hepatic function, thyroid function, immunity, and renal function, and encephalopathy. CPLANE1 (c.8948dupT (p.P2984Tfs*7) and c.247G > T (p.G83X)) variants were noticed in the patient as a pathogenic variant and caused autosomal recessive inheritance. The JBTS patient with mutations in CPLANE1 (c.8948dupT (p.P2984Tfs*7) and c.247G > T (p.G83X)) developed JBTS phenotypes. The novel CPLANE1 c.8948dupT (p.P2984Tfs*7) variant will assist clinicians and geneticists in reaching a precise diagnosis for JBTS.
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Affiliation(s)
- Huiping Wang
- Department of Neurology, Kunming Children’s Hospital, Kunming Children’s Hospital Affiliated with Kunming Medical University, No. 288, Qianxing Road, Xishan District, Kunming 650228, China
| | - Wensha Nie
- Department of Neurology, Kunming Children’s Hospital, Kunming Children’s Hospital Affiliated with Kunming Medical University, No. 288, Qianxing Road, Xishan District, Kunming 650228, China
| | - Chunxia Wang
- Department of Neurology, Kunming Children’s Hospital, Kunming Children’s Hospital Affiliated with Kunming Medical University, No. 288, Qianxing Road, Xishan District, Kunming 650228, China
| | - Zuohua Wang
- Department of Neurology, Kunming Children’s Hospital, Kunming Children’s Hospital Affiliated with Kunming Medical University, No. 288, Qianxing Road, Xishan District, Kunming 650228, China
| | - Yuxia Zheng
- Department of Neurology, Kunming Children’s Hospital, Kunming Children’s Hospital Affiliated with Kunming Medical University, No. 288, Qianxing Road, Xishan District, Kunming 650228, China
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Hussain S, Nawaz S, Khan H, Acharya A, Schrauwen I, Ahmad W, Leal SM. A splice site variant in TCTN3 underlies an atypical form of orofaciodigital syndrome IV. Ann Hum Genet 2022; 86:291-296. [PMID: 36039988 PMCID: PMC9804382 DOI: 10.1111/ahg.12462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 09/20/2021] [Accepted: 02/14/2022] [Indexed: 01/05/2023]
Abstract
Orofaciodigital syndrome (OFD) is clinically heterogeneous and is characterized by abnormalities in the oral cavity, facial features, digits, and central nervous system. At least 18 subtypes of the condition have been described in the literature. OFD is caused by variants in several genes with overlapping phenotypes. We studied a consanguineous Pakistani family with two affected siblings with an atypical form of OFD type 4 (OFD4). In addition to the typical features of OFD4 that include limb defects and growth retardation, the siblings displayed rare features of scaphocephaly and seizures. Exome sequencing analysis revealed a novel homozygous splice site variant c.257-1G>A in TCTN3 that segregated with disease. This homozygous splice site variant in TCTN3 is most likely the underlying cause of the atypical form of OFD4 observed in this family. Our results contribute to the phenotypic spectrum of TCTN3 associated ciliopathies and will facilitate better clinical diagnosis.
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Affiliation(s)
- Shabir Hussain
- Department of Biochemistry, Faculty of Biological SciencesQuaid‐i‐Azam UniversityIslamabadPakistan
| | - Shoaib Nawaz
- Department of Biotechnology, Faculty of Biological SciencesQuaid‐i‐Azam UniversityIslamabadPakistan
| | - Hammal Khan
- Department of Biochemistry, Faculty of Biological SciencesQuaid‐i‐Azam UniversityIslamabadPakistan,Department of BiosciencesCOMSATS UniversityIslamabadPakistan
| | - Anushree Acharya
- Center for Statistical Genetics, Gertrude H. Sergievsky Center, and the Department of NeurologyColumbia University Medical CenterNew YorkNew YorkUSA
| | - Isabelle Schrauwen
- Center for Statistical Genetics, Gertrude H. Sergievsky Center, and the Department of NeurologyColumbia University Medical CenterNew YorkNew YorkUSA
| | - Wasim Ahmad
- Department of Biochemistry, Faculty of Biological SciencesQuaid‐i‐Azam UniversityIslamabadPakistan
| | - Suzanne M. Leal
- Center for Statistical Genetics, Gertrude H. Sergievsky Center, and the Department of NeurologyColumbia University Medical CenterNew YorkNew YorkUSA,Taub Institute for Alzheimer's Disease and the Aging BrainColumbia University Medical CenterNew YorkNew YorkUSA
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6
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Chang KJ, Wu HY, Yarmishyn AA, Li CY, Hsiao YJ, Chi YC, Lo TC, Dai HJ, Yang YC, Liu DH, Hwang DK, Chen SJ, Hsu CC, Kao CL. Genetics behind Cerebral Disease with Ocular Comorbidity: Finding Parallels between the Brain and Eye Molecular Pathology. Int J Mol Sci 2022; 23:ijms23179707. [PMID: 36077104 PMCID: PMC9456058 DOI: 10.3390/ijms23179707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 08/18/2022] [Accepted: 08/22/2022] [Indexed: 11/30/2022] Open
Abstract
Cerebral visual impairments (CVIs) is an umbrella term that categorizes miscellaneous visual defects with parallel genetic brain disorders. While the manifestations of CVIs are diverse and ambiguous, molecular diagnostics stand out as a powerful approach for understanding pathomechanisms in CVIs. Nevertheless, the characterization of CVI disease cohorts has been fragmented and lacks integration. By revisiting the genome-wide and phenome-wide association studies (GWAS and PheWAS), we clustered a handful of renowned CVIs into five ontology groups, namely ciliopathies (Joubert syndrome, Bardet–Biedl syndrome, Alstrom syndrome), demyelination diseases (multiple sclerosis, Alexander disease, Pelizaeus–Merzbacher disease), transcriptional deregulation diseases (Mowat–Wilson disease, Pitt–Hopkins disease, Rett syndrome, Cockayne syndrome, X-linked alpha-thalassaemia mental retardation), compromised peroxisome disorders (Zellweger spectrum disorder, Refsum disease), and channelopathies (neuromyelitis optica spectrum disorder), and reviewed several mutation hotspots currently found to be associated with the CVIs. Moreover, we discussed the common manifestations in the brain and the eye, and collated animal study findings to discuss plausible gene editing strategies for future CVI correction.
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Affiliation(s)
- Kao-Jung Chang
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
| | - Hsin-Yu Wu
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | | | - Cheng-Yi Li
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Yu-Jer Hsiao
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Yi-Chun Chi
- Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Tzu-Chen Lo
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - He-Jhen Dai
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Yi-Chiang Yang
- Department of Physical Medicine and Rehabilitation, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Ding-Hao Liu
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Physical Medicine and Rehabilitation, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - De-Kuang Hwang
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Shih-Jen Chen
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Chih-Chien Hsu
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
- Correspondence: (C.-C.H.); (C.-L.K.); Tel.: +886-2-287-573-25 (C.-C.H.); +886-2-287-573-63 (C.-L.K.)
| | - Chung-Lan Kao
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Physical Medicine and Rehabilitation, Taipei Veterans General Hospital, Taipei 11217, Taiwan
- Department of Physical Medicine and Rehabilitation, School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Center for Intelligent Drug Systems and Smart Bio-Devices (IDS2B), National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan
- Correspondence: (C.-C.H.); (C.-L.K.); Tel.: +886-2-287-573-25 (C.-C.H.); +886-2-287-573-63 (C.-L.K.)
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7
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Shirah BH, Alshaikh NM, Shawli A, Naseer MI. Clinical and molecular characteristics of tectonic (TCTN1) gene-related Joubert syndrome in a Saudi boy. Brain Dev 2022; 44:299-302. [PMID: 34980503 DOI: 10.1016/j.braindev.2021.12.005] [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] [Received: 09/21/2021] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 10/19/2022]
Abstract
Joubert syndrome (OMIM:609863) is a hereditary disorder characterized by hypotonia, developmental delay, and a distinctive cerebellar and brain stem malformation known as the molar tooth sign. Variants in tectonic genes TCTN1-3 have been described in a few patients with Joubert syndrome. Furthermore, Joubert syndrome attributed to variants in the TCTN1 (NM_001082538.2) gene has been only described in two reports. This report expands the clinical variability and molecular characterization of an emerging novel causative gene for Joubert syndrome in a Saudi boy born to non-consanguineous marriage with a c.1418del p.(Pro473Leufs*42) and c.800A > G p.(Tyr267Cys) representing a novel compound heterozygous variant of the TCTN1 gene identified by whole-exome sequencing and confirmed by Sanger sequencing. This is the first report of compound heterozygous Joubert syndrome type 13 from Saudi Arabia.
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Affiliation(s)
- Bader H Shirah
- Department of Neuroscience, King Faisal Specialist Hospital & Research Centre, Jeddah, Saudi Arabia
| | - Nahla M Alshaikh
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia; King Abdullah International Medical Research Center, Jeddah, Saudi Arabia; Pediatric Department, Ministry of National Guard Health Affairs, Jeddah, Saudi Arabia.
| | - Ayman Shawli
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia; King Abdullah International Medical Research Center, Jeddah, Saudi Arabia; Pediatric Department, Ministry of National Guard Health Affairs, Jeddah, Saudi Arabia
| | - Muhammad Imran Naseer
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah, Saudi Arabia; Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
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8
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Gana S, Serpieri V, Valente EM. Genotype-phenotype correlates in Joubert syndrome: A review. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2022; 190:72-88. [PMID: 35238134 PMCID: PMC9314610 DOI: 10.1002/ajmg.c.31963] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/04/2022] [Accepted: 02/15/2022] [Indexed: 01/20/2023]
Abstract
Joubert syndrome (JS) is a genetically heterogeneous primary ciliopathy characterized by a pathognomonic cerebellar and brainstem malformation, the “molar tooth sign,” and variable organ involvement. Over 40 causative genes have been identified to date, explaining up to 94% of cases. To date, gene‐phenotype correlates have been delineated only for a handful of genes, directly translating into improved counseling and clinical care. For instance, JS individuals harboring pathogenic variants in TMEM67 have a significantly higher risk of liver fibrosis, while pathogenic variants in NPHP1, RPGRIP1L, and TMEM237 are frequently associated to JS with renal involvement, requiring a closer monitoring of liver parameters, or renal functioning. On the other hand, individuals with causal variants in the CEP290 or AHI1 need a closer surveillance for retinal dystrophy and, in case of CEP290, also for chronic kidney disease. These examples highlight how an accurate description of the range of clinical symptoms associated with defects in each causative gene, including the rare ones, would better address prognosis and help guiding a personalized management. This review proposes to address this issue by assessing the available literature, to confirm known, as well as to propose rare gene‐phenotype correlates in JS.
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Affiliation(s)
- Simone Gana
- Neurogenetics Research Center, IRCCS Mondino Foundation, Pavia, Italy
| | | | - Enza Maria Valente
- Neurogenetics Research Center, IRCCS Mondino Foundation, Pavia, Italy.,Department of Molecular Medicine, University of Pavia, Pavia, Italy
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Huljev Frković S, Vičić A, Crkvenac Gornik K, Kulišić D, Stipoljev F. Prenatally detected encephalocele associated with a novel pathogenic TCTN3 variant: A case report and literature review. Am J Med Genet A 2022; 188:1826-1830. [PMID: 35170189 DOI: 10.1002/ajmg.a.62684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 01/18/2022] [Accepted: 01/20/2022] [Indexed: 11/06/2022]
Abstract
Primary cilia are a component of almost all vertebrate cells with a crucial role in sensing and transducing environmental signals during tissue development. Their dysfunction is known as ciliopathies and can manifest with a wide spectrum of clinical disorders. Overlapping features and molecular heterogeneity of ciliopathies make diagnoses distinctly challenging. In this group of diseases, tectonic genes, and their mutations play an important role. We present a first-trimester fetus with occipital encephalocele and OFD type IV caused by TCTN3 compound heterozygous pathogenic variants: c.1423_1429del (p.Arg475Serfs*10) and c.3G>A (initiator codon). A severe arm anomaly was described in our case, with two fingers along the atrophic forearm and polydactyly on other limbs. This could be a new phenotypic characteristic contributing to further understanding of TCTN3-related disorders as well as other tectonic proteins in ciliopathy spectrum diseases.
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Affiliation(s)
- Sanda Huljev Frković
- Department of Paediatrics, Division for genetics and metabolism, University of Zagreb School of Medicine, University Hospital Centre Zagreb, Zagreb, Croatia
| | - Ana Vičić
- Cytogenetic Laboratory, Department of Obstetrics and Gynecology, Clinical Hospital "Sveti Duh", Zagreb, Croatia.,University of Applied Health Sciences, Zagreb, Croatia
| | - Kristina Crkvenac Gornik
- Department of Laboratory Diagnostics, Division of Cytogenetics, University Hospital Centre Zagreb, Zagreb, Croatia
| | - Dinko Kulišić
- Department of Gynecology and Obstetrics, General Hospital Zadar, Zadar, Croatia
| | - Feodora Stipoljev
- Cytogenetic Laboratory, Department of Obstetrics and Gynecology, Clinical Hospital "Sveti Duh", Zagreb, Croatia.,Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
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10
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Abrams SR, Reiter JF. Ciliary Hedgehog signaling regulates cell survival to build the facial midline. eLife 2021; 10:e68558. [PMID: 34672258 PMCID: PMC8592574 DOI: 10.7554/elife.68558] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 10/20/2021] [Indexed: 01/03/2023] Open
Abstract
Craniofacial defects are among the most common phenotypes caused by ciliopathies, yet the developmental and molecular etiology of these defects is poorly understood. We investigated multiple mouse models of human ciliopathies (including Tctn2, Cc2d2a, and Tmem231 mutants) and discovered that each displays hypotelorism, a narrowing of the midface. As early in development as the end of gastrulation, Tctn2 mutants displayed reduced activation of the Hedgehog (HH) pathway in the prechordal plate, the head organizer. This prechordal plate defect preceded a reduction of HH pathway activation and Shh expression in the adjacent neurectoderm. Concomitant with the reduction of HH pathway activity, Tctn2 mutants exhibited increased cell death in the neurectoderm and facial ectoderm, culminating in a collapse of the facial midline. Enhancing HH signaling by decreasing the gene dosage of a negative regulator of the pathway, Ptch1, decreased cell death and rescued the midface defect in both Tctn2 and Cc2d2a mutants. These results reveal that ciliary HH signaling mediates communication between the prechordal plate and the neurectoderm to provide cellular survival cues essential for development of the facial midline.
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Affiliation(s)
- Shaun R Abrams
- Department of Biochemistry and Biophysics, Cardiovascular Research InstituteSan FranciscoUnited States
- Oral and Craniofacial Sciences Program, School of DentistrySan FranciscoUnited States
| | - Jeremy F Reiter
- Department of Biochemistry and Biophysics, Cardiovascular Research InstituteSan FranciscoUnited States
- Chan Zuckerberg BiohubSan FranciscoUnited States
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11
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Turkyilmaz A, Geckinli BB, Alavanda C, Arslan Ates E, Buyukbayrak EE, Eren SF, Arman A. Meckel-Gruber Syndrome: Clinical and Molecular Genetic Profiles in Two Fetuses and Review of the Current Literature. Genet Test Mol Biomarkers 2021; 25:445-451. [PMID: 34096792 DOI: 10.1089/gtmb.2020.0311] [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] [Indexed: 11/12/2022] Open
Abstract
Background: Meckel-Gruber syndrome (MKS; OMIM No. 249000) is a rare, in utero lethal disease characterized by occipital encephalocele, polycystic kidneys, and polydactyly. Methodology and Results: In this study, two fetuses diagnosed as having MKS in the prenatal period were evaluated on the basis of ultrasonographic findings, postmortem autopsy findings, and molecular genetic analyses. Using exome sequencing analyses a novel homozygous frameshift variant (NM_015631: c.530delA, p.Lys177Argfs*47) was detected at exon 4 of TCTN3 gene in case 1, and a novel homozygous synonymous variant (NM_025114: c.180G>A, p Lys60Lys) was detected at exon 3 of CEP290 gene in case 2. Case 1 is the first reported case in the literature, which showed the typical MKS clinical feature with a novel frameshift variation in the TCTN3 gene. The variant in case 2 is the first reported synonymous variant of CEP290 gene in the literature, which has been shown to affect splicing in a functional study at the RNA level. Conclusion: TCTN3 gene variants that were rarely associated with the typical MKS phenotype and all cases with these variations have been discussed in the context of genotype-phenotype. The detection of the first synonymous variant of CEP290 gene and the demonstration of its effect on splicing by a functional study are likely to contribute to the molecular etiology of MKS.
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Affiliation(s)
- Ayberk Turkyilmaz
- Department of Medical Genetics, School of Medicine, Karadeniz Technical University, Trabzon, Turkey
| | - Bilgen Bilge Geckinli
- Department of Medical Genetics, School of Medicine, Marmara University, Istanbul, Turkey
| | - Ceren Alavanda
- Department of Medical Genetics, School of Medicine, Marmara University, Istanbul, Turkey
| | - Esra Arslan Ates
- Department of Medical Genetics, Marmara University Pendik Training and Research Hospital, Istanbul, Turkey
| | | | - Sirin Funda Eren
- Department of Pathology, School of Medicine, Marmara University, Istanbul, Turkey
| | - Ahmet Arman
- Department of Medical Genetics, School of Medicine, Marmara University, Istanbul, Turkey
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12
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Baumgartner M, Drake K, Kanadia RN. An Integrated Model of Minor Intron Emergence and Conservation. Front Genet 2019; 10:1113. [PMID: 31798628 PMCID: PMC6865273 DOI: 10.3389/fgene.2019.01113] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Accepted: 10/16/2019] [Indexed: 12/12/2022] Open
Abstract
Minor introns constitute <0.5% of the introns in the human genome and have remained an enigma since their discovery. These introns are removed by a distinct splicing complex, the minor spliceosome. Both are ancient, tracing back to the last eukaryotic common ancestor (LECA), which is reflected by minor intron enrichment in specific gene families, such as the mitogen activated-protein kinase kinases, voltage-gated sodium and calcium ion channels, and E2F transcription factors. Most minor introns occur as single introns in genes with predominantly major introns. Due to this organization, minor intron-containing gene (MIG) expression requires the coordinated action of two spliceosomes, which increases the probability of missplicing. Thus, one would expect loss of minor introns via purifying selection. This has resulted in complete minor intron loss in at least nine eukaryotic lineages. However, minor introns are highly conserved in land plants and metazoans, where their importance is underscored by embryonic lethality when the minor spliceosome is inactivated. Conditional inactivation of the minor spliceosome has shown that rapidly dividing progenitor cells are highly sensitive to minor spliceosome loss. Indeed, we found that MIGs were significantly enriched in a screen for genes essential for survival in 341 cycling cell lines. Here, we propose that minor introns inserted randomly into genes in LECA or earlier and were subsequently conserved in genes crucial for cycling cell survival. We hypothesize that the essentiality of MIGs allowed minor introns to endure through the unicellularity of early eukaryotic evolution. Moreover, we identified 59 MIGs that emerged after LECA, and that many of these are essential for cycling cell survival, reinforcing our essentiality model for MIG conservation. This suggests that minor intron emergence is dynamic across eukaryotic evolution, and that minor introns should not be viewed as molecular fossils. We also posit that minor intron splicing was co-opted in multicellular evolution as a regulatory switch for en masse control of MIG expression and the biological processes they regulate. Specifically, this mode of regulation could control cell proliferation and thus body size, an idea supported by domestication syndrome, wherein MIGs are enriched in common candidate animal domestication genes.
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Affiliation(s)
- Marybeth Baumgartner
- Department of Physiology and Neurobiology, University of Connecticut, Mansfield, CT, United States.,Institute of Brain and Cognitive Sciences, University of Connecticut, Mansfield, CT, United States
| | - Kyle Drake
- Department of Physiology and Neurobiology, University of Connecticut, Mansfield, CT, United States
| | - Rahul N Kanadia
- Department of Physiology and Neurobiology, University of Connecticut, Mansfield, CT, United States.,Institute of Systems Genomics, University of Connecticut, Mansfield, CT, United States
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13
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Wheway G, Lord J, Baralle D. Splicing in the pathogenesis, diagnosis and treatment of ciliopathies. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1862:194433. [PMID: 31698098 DOI: 10.1016/j.bbagrm.2019.194433] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 09/12/2019] [Accepted: 09/17/2019] [Indexed: 12/12/2022]
Abstract
Primary cilia are essential signalling organelles found on the apical surface of epithelial cells, where they coordinate chemosensation, mechanosensation and light sensation. Motile cilia play a central role in establishing fluid flow in the respiratory tract, reproductive tract, brain ventricles and ear. Genetic defects affecting the structure or function of cilia can lead to a broad range of developmental and degenerative diseases known as ciliopathies. Splicing contributes to the pathogenesis, diagnosis and treatment of ciliopathies. Tissue-specific alternative splicing contributes to the tissue-specific manifestation of ciliopathy phenotypes, for example the retinal-specific effects of some genetic defects, due to specific transcript expression in the highly specialised ciliated cells of the retina, the photoreceptor cells. Ciliopathies can arise both as a result of genetic variants in spliceosomal proteins, or as a result of variants affecting splicing of specific cilia genes. Here we discuss the opportunities and challenges in diagnosing ciliopathies using RNA sequence analysis and the potential for treating ciliopathies in a relatively mutation-neutral way by targeting splicing. This article is part of a Special Issue entitled: RNA structure and splicing regulation edited by Francisco Baralle, Ravindra Singh and Stefan Stamm.
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Affiliation(s)
- Gabrielle Wheway
- Faculty of Medicine, University of Southampton, Human Development and Health, United Kingdom of Great Britain and Northern Ireland; University Hospital Southampton NHS Foundation Trust, United Kingdom of Great Britain and Northern Ireland
| | - Jenny Lord
- Faculty of Medicine, University of Southampton, Human Development and Health, United Kingdom of Great Britain and Northern Ireland; University Hospital Southampton NHS Foundation Trust, United Kingdom of Great Britain and Northern Ireland
| | - Diana Baralle
- Faculty of Medicine, University of Southampton, Human Development and Health, United Kingdom of Great Britain and Northern Ireland; University Hospital Southampton NHS Foundation Trust, United Kingdom of Great Britain and Northern Ireland.
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14
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Greenbaum L, Pode-Shakked B, Eisenberg-Barzilai S, Dicastro-Keidar M, Bar-Ziv A, Goldstein N, Reznik-Wolf H, Poran H, Rigbi A, Barel O, Bertoli-Avella AM, Bauer P, Regev M, Raas-Rothschild A, Pras E, Berkenstadt M. Evaluation of Diagnostic Yield in Fetal Whole-Exome Sequencing: A Report on 45 Consecutive Families. Front Genet 2019; 10:425. [PMID: 31428121 PMCID: PMC6688107 DOI: 10.3389/fgene.2019.00425] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Accepted: 04/17/2019] [Indexed: 11/13/2022] Open
Abstract
Prenatal ultrasound (US) abnormalities often pose a clinical dilemma and necessitate facilitated investigations in the search of diagnosis. The strategy of pursuing fetal whole-exome sequencing (WES) for pregnancies complicated by abnormal US findings is gaining attention, but the reported diagnostic yield is variable. In this study, we describe a tertiary center's experience with fetal WES from both terminated and ongoing pregnancies, and examine the clinical factors affecting the diagnostic rate. A total of 45 consecutive families of Jewish descent were included in the analysis, for which clinical fetal WES was performed under either single (fetus only), trio (fetus and parents) or quatro (two fetuses and parents) design. Except one, all families were non-consanguineous. In 41 of the 45 families, WES was sought following abnormal fetal US findings, and 18 of them had positive relevant family history (two or more fetuses with US abnormalities, or single fetus with US abnormalities and an affected parent). The overall diagnostic yield was 28.9% (13/45 families), and 31.7% among families with fetal US abnormalities (13/41). It was significantly higher in families with prenatal US abnormalities and relevant family history (10/18, 55.6%), compared to families with prenatal US abnormal findings and lack of such history (3/23, 13%) (p = 0.004). WES yield was relatively high (42.9-60%) among families with involvement of brain, renal or musculoskeletal US findings. Taken together, our results in a real-world setting of genetic counseling demonstrates that fetal WES is especially indicated in families with positive family history, as well as in fetuses with specific types of congenital malformation.
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Affiliation(s)
- Lior Greenbaum
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Israel.,The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ben Pode-Shakked
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | | | - Michal Dicastro-Keidar
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Israel
| | - Anat Bar-Ziv
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Israel
| | - Nurit Goldstein
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Israel
| | - Haike Reznik-Wolf
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Israel
| | - Hana Poran
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Israel
| | - Amihai Rigbi
- Faculty of Education, Beit Berl College, Kfar Saba, Israel
| | - Ortal Barel
- Sheba Cancer Research Center, Sheba Medical Center, Tel Hashomer, Israel
| | | | | | - Miriam Regev
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Annick Raas-Rothschild
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Elon Pras
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Michal Berkenstadt
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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15
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Review of Ocular Manifestations of Joubert Syndrome. Genes (Basel) 2018; 9:genes9120605. [PMID: 30518138 PMCID: PMC6315342 DOI: 10.3390/genes9120605] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 11/13/2018] [Accepted: 11/27/2018] [Indexed: 12/13/2022] Open
Abstract
Joubert syndrome is a group of rare disorders that stem from defects in a sensory organelle, the primary cilia. Affected patients often present with disorders involving multiple organ systems, including the brain, eyes, and kidneys. Common symptoms include breathing abnormalities, mental developmental delays, loss of voluntary muscle coordination, and abnormal eye movements, with a diagnostic “molar tooth” sign observed by magnetic resonance imaging (MRI) of the midbrain. We reviewed the ocular phenotypes that can be found in patients with Joubert syndrome. Ocular motor apraxia is the most frequent (80% of patients), followed by strabismus (74%) and nystagmus (72%). A minority of patients also present with ptosis (43%), chorioretinal coloboma (30%), and optic nerve atrophy (22%). Although mutations in 34 genes have been found to be associated with Joubert syndrome, retinal degeneration has been reported in only 38% of patients. Mutations in AHI1 and CEP290, genes critical to primary cilia function, have been linked to retinal degeneration. In conclusion, Joubert syndrome is a rare pleiotropic group of disorders with variable ocular presentations.
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16
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Wang B, Zhang Y, Dong H, Gong S, Wei B, Luo M, Wang H, Wu X, Liu W, Xu X, Zheng Y, Sun M. Loss of Tctn3 causes neuronal apoptosis and neural tube defects in mice. Cell Death Dis 2018; 9:520. [PMID: 29725084 PMCID: PMC5938703 DOI: 10.1038/s41419-018-0563-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 03/23/2018] [Accepted: 04/03/2018] [Indexed: 12/18/2022]
Abstract
Tctn3 belongs to the Tectonic (Tctn) family and is a single-pass membrane protein localized at the transition zone of primary cilia as an important component of ciliopathy-related protein complexes. Previous studies showed that mutations in Tctn1 and Tctn2, two members of the tectonic family, have been reported to disrupt neural tube development in humans and mice, but the functions of Tctn3 in brain development remain elusive. In this study, Tctn3 knockout (KO) mice were generated by utilizing the piggyBac (PB) transposon system. We found that Tctn3 KO mice exhibited abnormal global development, including prenatal lethality, microphthalmia, polysyndactyly, and abnormal head, sternum, and neural tube, whereas Tctn3 heterozygous KO mice did not show abnormal development or behaviors. Further, we found that the mRNA levels of Gli1 and Ptch1, downstream signaling components of the Shh pathway, were significantly reduced. Likewise, neural tube patterning-related proteins, such as Shh, Foxa2, and Nkx2.2, were altered in their distribution. Interestingly, Tctn3 KO led to significant changes in apoptosis-related proteins, including Bcl-2, Bax, and cleaved PARP1, resulting in reduced numbers of neuronal cells in embryonic brains. Tctn3 KO inhibited the PI3K/Akt signaling pathway but not the mTOR-dependent pathway. The small molecule SC79, a specific Akt activator, blocked apoptotic cell death in primary mouse embryonic fibroblasts from Tctn3 KO mice. Finally, NPHP1, a protein with anti-apoptotic ability, was found to form a complex with Tctn3, and its levels were decreased in Tctn3 KO mice. In conclusion, our results show that Tctn3 KO disrupts the Shh signaling pathway and neural tube patterning, resulting in abnormal embryonic development, cellular apoptosis, and prenatal death in mice.
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Affiliation(s)
- Bin Wang
- Institute for Fetology, the First Affiliated Hospital of Soochow University, Suzhou City, 215006, Jiangsu, China.,Institute of Neuroscience, Soochow University, Suzhou City, 215123, Jiangsu, China
| | - Yingying Zhang
- Institute for Fetology, the First Affiliated Hospital of Soochow University, Suzhou City, 215006, Jiangsu, China
| | - Hongli Dong
- Department of Neurology, Suzhou Hospital of Traditional Chinese Medicine, Suzhou City, 215123, Jiangsu, China
| | - Siyi Gong
- Institute for Fetology, the First Affiliated Hospital of Soochow University, Suzhou City, 215006, Jiangsu, China.,Institute of Neuroscience, Soochow University, Suzhou City, 215123, Jiangsu, China
| | - Bin Wei
- Institute for Fetology, the First Affiliated Hospital of Soochow University, Suzhou City, 215006, Jiangsu, China
| | - Man Luo
- Institute of Neuroscience, Soochow University, Suzhou City, 215123, Jiangsu, China
| | - Hongyan Wang
- Obstetrics and Gynecology Hospital Research Center, Institute of Reproduction and Development, Fudan University, Shanghai, 200433, China.,State Key Laboratory of Genetic Engineering, MOE Key Laboratory of Contemporary Anthropology, and Collaborative Innovation Center for Genetics & Development, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Xiaohui Wu
- State Key Laboratory of Genetic Engineering, MOE Key Laboratory of Contemporary Anthropology, and Collaborative Innovation Center for Genetics & Development, School of Life Sciences, Fudan University, Shanghai, 200438, China.,Institute of Developmental Biology & Molecular Medicine, Fudan University, Shanghai, 200433, China
| | - Wei Liu
- Department of Pathology, the First Affiliated Hospital of Soochow University, Suzhou City, 215006, Jiangsu, China
| | - Xingshun Xu
- Institute of Neuroscience, Soochow University, Suzhou City, 215123, Jiangsu, China.
| | - Yufang Zheng
- Obstetrics and Gynecology Hospital Research Center, Institute of Reproduction and Development, Fudan University, Shanghai, 200433, China. .,State Key Laboratory of Genetic Engineering, MOE Key Laboratory of Contemporary Anthropology, and Collaborative Innovation Center for Genetics & Development, School of Life Sciences, Fudan University, Shanghai, 200438, China. .,Institute of Developmental Biology & Molecular Medicine, Fudan University, Shanghai, 200433, China.
| | - Miao Sun
- Institute for Fetology, the First Affiliated Hospital of Soochow University, Suzhou City, 215006, Jiangsu, China.
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17
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Arrigoni F, Romaniello R, Peruzzo D, De Luca A, Parazzini C, Valente EM, Borgatti R, Triulzi F. Anterior Mesencephalic Cap Dysplasia: Novel Brain Stem Malformative Features Associated with Joubert Syndrome. AJNR Am J Neuroradiol 2017; 38:2385-2390. [PMID: 28838911 DOI: 10.3174/ajnr.a5360] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 06/30/2017] [Indexed: 11/07/2022]
Abstract
In Joubert syndrome, the "molar tooth" sign can be associated with several additional supra- and infratentorial malformations. Here we report on 3 subjects (2 siblings, 8-14 years of age) with Joubert syndrome, showing an abnormal thick bulging of the anterior profile of the mesencephalon causing a complete obliteration of the interpeduncular fossa. DTI revealed that the abnormal tissue consisted of an ectopic white matter tract with a laterolateral transverse orientation. Tractographic reconstructions support the hypothesis of impaired axonal guidance mechanisms responsible for the malformation. The 2 siblings were compound heterozygous for 2 missense variants in the TMEM67 gene, while no mutations in a panel of 120 ciliary genes were detected in the third patient. The name "anterior mesencephalic cap dysplasia," referring to the peculiar aspect of the mesencephalon on sagittal MR imaging, is proposed for this new malformative feature.
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Affiliation(s)
- F Arrigoni
- From the Neuroimaging Lab (F.A., D.P., A.D.L.)
| | - R Romaniello
- Neuropsychiatry and Neurorehabilitation Unit (R.R., R.B.), Scientific Institute Istituto Di Ricovero e Cura a Carattere Scientific Eugenio Medea, Bosisio Parini, Italy
| | - D Peruzzo
- From the Neuroimaging Lab (F.A., D.P., A.D.L.)
| | - A De Luca
- From the Neuroimaging Lab (F.A., D.P., A.D.L.)
- Department of Information Engineering (A.D.L.), University of Padova, Padova, Italy
| | - C Parazzini
- Department of Pediatric Radiology and Neuroradiology (C.P.), "V. Buzzi" Children's Hospital, Milan, Italy
| | - E M Valente
- Department of Molecular Medicine (E.M.V.), University of Pavia, Pavia, Italy
- Neurogenetics Unit (E.M.V.), Istituto Di Ricovero e Cura a Carattere Scientific Santa Lucia Foundation, Rome, Italy
| | - R Borgatti
- Neuropsychiatry and Neurorehabilitation Unit (R.R., R.B.), Scientific Institute Istituto Di Ricovero e Cura a Carattere Scientific Eugenio Medea, Bosisio Parini, Italy
| | - F Triulzi
- Department of Neuroradiology (F.T.), Scientific Institute Istituto Di Ricovero e Cura a Carattere Scientific Cà Granda Foundation-Ospedale Maggiore Policlinico, Milan, Italy
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18
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Abstract
INTRODUCTION Joubert syndrome (JS) is a rare autosomal recessive inherited disease belonging to ciliopathy with the causative mutation of genes. Except for X-linked inheritance, the high recurrence rate of a family is about 25%. After birth, it may cause a series of neurological symptoms, even with retina, kidney, liver, and other organ abnormalities, which is defined as Joubert syndrome and related disorders (JSRD). Molecular genetics research contributes to disease prediction and genetic counseling. Prenatal diagnosis is rare. Magnetic resonance imaging (MRI) is usually the first-choice diagnostic modality with typical brain images characterized by the molar tooth sign. We describe a case of JS prenatally and Dandy-Walker malformation for the differential diagnosis based on ultrasonograms. We also review the etiology, imaging features, clinical symptoms, and diagnosis of JSRD. CASE PRESENTATION A 22-year-old woman was pregnant at 27 1/7 weeks' gestation with fetal cerebellar vermis hypoplasia. Fetal ultrasonography and MRI confirmed a diagnosis of JS at our center. The couple finally opted to terminate the fetus, which had a normal appearance and growth parameters. The couple also had an AHI1 gene mutation on chromosome 6. CONCLUSIONS Currently, a diagnosis of JS is commonly made after birth. Fewer cases of prenatal diagnosis by ultrasonography have been made, and they are more liable to be misdirected because of some nonspecial features that also manifest in Dandy-Walker malformation, cranio-cerebello-cardiac syndrome, and so on.
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19
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Xu P, Xia X, Yang Z, Tian Y, Di J, Guo M. Silencing of TCTN1 inhibits proliferation, induces cell cycle arrest and apoptosis in human thyroid cancer. Exp Ther Med 2017; 14:3720-3726. [PMID: 29042969 PMCID: PMC5639387 DOI: 10.3892/etm.2017.4940] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 07/10/2017] [Indexed: 12/31/2022] Open
Abstract
Tectonic family member 1 (TCTN1) is one of the tectonic family members, and a regulator of the hedgehog signaling pathway, which has been studied in various cancer types, including prostate and pancreatic cancer. However, its function in thyroid cancer has not been well documented. Therefore, the present study investigated the function of TCTN1 in thyroid cancer using a loss-of-function assay. Lentivirus-mediated RNA interference was applied to downregulate TCTN1 in the thyroid cancer cell lines, CAL62 and 8305C. A series of functional properties, including cell viability, colony formation, cell cycle and apoptosis were determined using MTT, colony formation assay and flow cytometry analyses, respectively. The results demonstrated that lentivirus-medicated RNAi could specifically suppress the expression of TCTN1 at the mRNA and protein levels in CAL62, and 8305C cells. Knockdown of TCTN1 inhibited cell growth and proliferation via inducing S phase arrest, and apoptosis. Mechanistically, the S phase arrest was accompanied by the upregulation of cyclin dependent kinase 2, cyclin A2 and downregulation of cyclin B1. Knockdown of TCTN1 induced apoptosis through increasing the expression of Bcl2-associated agonist of cell death, cleaved caspase-3 and poly(ADP-ribose)polymerase, and decreasing apoptosis regulator Bcl-2 expression. The current study highlights the essential role of TCTN1 in promoting thyroid cancer cell proliferation, and its knockdown may serve as a potential therapeutic treatment for thyroid cancer.
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Affiliation(s)
- Peipei Xu
- Department of Surgery, The Sixth People's Hospital of Shanghai, Shanghai Jiaotong University, Shanghai 200233, P.R. China
| | - Xiaotian Xia
- Department of Surgery, The Sixth People's Hospital of Shanghai, Shanghai Jiaotong University, Shanghai 200233, P.R. China
| | - Zhili Yang
- Department of Surgery, The Sixth People's Hospital of Shanghai, Shanghai Jiaotong University, Shanghai 200233, P.R. China
| | - Yuan Tian
- Department of Surgery, The Sixth People's Hospital of Shanghai, Shanghai Jiaotong University, Shanghai 200233, P.R. China
| | - Jianzhong Di
- Department of Surgery, The Sixth People's Hospital of Shanghai, Shanghai Jiaotong University, Shanghai 200233, P.R. China.,Department of Surgery, The People's Hospital of Xigaze, 857000 Tibet, P.R. China
| | - Minggao Guo
- Department of Surgery, The Sixth People's Hospital of Shanghai, Shanghai Jiaotong University, Shanghai 200233, P.R. China
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20
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Al-Qattan MM, Shaheen R, Alkuraya FS. Expanding the allelic disorders linked to TCTN1 to include Varadi syndrome (Orofaciodigital syndrome type VI). Am J Med Genet A 2017. [PMID: 28631893 DOI: 10.1002/ajmg.a.38336] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Varadi syndrome is a subtype of orofaciodigital syndrome (OFDS) that combines the typical features of OFDS and the posterior fossa features of Joubert syndrome. The only gene known to be mutated in Varadi syndrome is C5ORF42. In this report, we describe the phenotype of a patient with Varadi syndrome who is homozygous for a previously reported mutation in TCTN1 (NM_001082538.2:c.342-2A>G, p.Gly115Lysfs*8) and suggest that allelic disorders linked to TCTN1 include Varadi syndrome, in addition to Joubert syndrome and Meckel-Gruber syndrome.
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Affiliation(s)
| | - Ranad Shaheen
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
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21
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Garcia-Gonzalo FR, Reiter JF. Open Sesame: How Transition Fibers and the Transition Zone Control Ciliary Composition. Cold Spring Harb Perspect Biol 2017; 9:cshperspect.a028134. [PMID: 27770015 DOI: 10.1101/cshperspect.a028134] [Citation(s) in RCA: 166] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cilia are plasma membrane protrusions that act as cellular propellers or antennae. To perform these functions, cilia must maintain a composition distinct from those of the contiguous cytosol and plasma membrane. The specialized composition of the cilium depends on the ciliary gate, the region at the ciliary base separating the cilium from the rest of the cell. The ciliary gate's main structural features are electron dense struts connecting microtubules to the adjacent membrane. These structures include the transition fibers, which connect the distal basal body to the base of the ciliary membrane, and the Y-links, which connect the proximal axoneme and ciliary membrane within the transition zone. Both transition fibers and Y-links form early during ciliogenesis and play key roles in ciliary assembly and trafficking. Accordingly, many human ciliopathies are caused by mutations that perturb ciliary gate function.
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Affiliation(s)
- Francesc R Garcia-Gonzalo
- Departamento de Bioquímica, Facultad de Medicina, and Instituto de Investigaciones Biomédicas Alberto Sols UAM-CSIC, Universidad Autónoma de Madrid, 28029 Madrid, Spain
| | - Jeremy F Reiter
- Department of Biochemistry and Biophysics, and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California 94158
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22
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Zhao S, Chen X, Wan M, Jiang X, Li C, Cui Y, Kang P. Tectonic 1 Is a Key Regulator of Cell Proliferation in Pancreatic Cancer. Cancer Biother Radiopharm 2016; 31:7-13. [PMID: 26844847 DOI: 10.1089/cbr.2014.1778] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Pancreatic cancer is notoriously becoming one of the most devastating human cancers leading to death. However, clinical challenges still remain in diagnosis and treatment of this ticklish cancer. In the present study, the authors identified a new gene, Tectonic 1 (TCTN1), as a key regulator of cell proliferation in pancreatic cancer. Lentivirus-mediated short hairpin RNA (shRNA) was employed to knock down endogenous TCTN1 expression in PANC-1 pancreatic cancer cells. Knockdown of TCTN1 expression potently inhibited cell viability and proliferation, as determined by MTT and colony formation assays. Western blotting analysis also showed that knockdown of TCTN1 suppressed the expression of cdc2, while it induced that of p21 and p27. Flow cytometry analysis showed that depletion of TCTN1 in PANC-1 cells led to cell cycle arrest in the G2/M phase as well as apoptosis. Besides, depletion of TCTN1 led to the increase of Bax and cleavage of PARP-1, but the decrease of bcl2 by western blotting. The data indicate that TCTN1 is indispensable for pancreatic cancer cell proliferation, which provides a novel alternative to targeted therapy of pancreatic cancer and deserves further investigation.
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Affiliation(s)
- Shiyong Zhao
- 1 Department of General Surgery, the Second Affiliated Hospital of Harbin Medical University , Harbin, China
| | - Xuedong Chen
- 2 Department of Ophthalmology, the First Affiliated Hospital of Harbin Medical University , Harbin, China
| | - Ming Wan
- 3 Harbin Medical University , Harbin, China
| | - Xingming Jiang
- 1 Department of General Surgery, the Second Affiliated Hospital of Harbin Medical University , Harbin, China
| | - Chunlong Li
- 1 Department of General Surgery, the Second Affiliated Hospital of Harbin Medical University , Harbin, China
| | - Yunfu Cui
- 1 Department of General Surgery, the Second Affiliated Hospital of Harbin Medical University , Harbin, China
| | - Pengcheng Kang
- 1 Department of General Surgery, the Second Affiliated Hospital of Harbin Medical University , Harbin, China
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23
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Bader I, Decker E, Mayr JA, Lunzer V, Koch J, Boltshauser E, Sperl W, Pietsch P, Ertl-Wagner B, Bolz H, Bergmann C, Rittinger O. MKS1 mutations cause Joubert syndrome with agenesis of the corpus callosum. Eur J Med Genet 2016; 59:386-91. [PMID: 27377014 DOI: 10.1016/j.ejmg.2016.06.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 06/25/2016] [Accepted: 06/28/2016] [Indexed: 11/17/2022]
Abstract
Joubert syndrome (JS) is a clinically and genetically heterogeneous ciliopathy characterized by episodic hyperpnea and apnea, hypotonia, ataxia, cognitive impairment and ocular motor apraxia. The "molar tooth sign" is pathognomonic of this condition. Mutations in the MKS1 gene are a major cause of Meckel-Gruber syndrome (MKS), the most common form of syndromic neural tube defects, frequently resulting in perinatal lethality. We present the phenotype and genotype of a child with severe JS and agenesis of the corpus callosum (ACC). In our patient, a next generation sequencing (NGS) approach revealed the following two variants of the MKS1 gene: first, a novel missense variant [ c.240G > T (p.Trp80Cys)], which affects a residue that is evolutionarily highly conserved in mammals and ciliates; second, a 29 bp deletion in intron 15 [c.1408-35_1408-7del29], a founder mutation, which in a homozygous state constitutes the major cause of MKS in Finland. We review the MKS1-variants in all of the eleven JS patients reported to date and compare these patients to our case. To our knowledge, this is the first patient with Joubert syndrome and agenesis of the corpus callosum where a potentially causal genotype is provided.
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Affiliation(s)
- Ingrid Bader
- Clinical Genetics Unit, Children's Hospital, Paracelsus Medical University, Salzburg, Austria; kbo-Kinderzentrum, Technische Universität München, Germany.
| | - E Decker
- Bioscientia, Center for Human Genetics, Ingelheim, Germany
| | - J A Mayr
- Children's Hospital, Paracelsus Medical University, Salzburg, Austria
| | - V Lunzer
- Children's Hospital, Paracelsus Medical University, Salzburg, Austria
| | - J Koch
- Children's Hospital, Paracelsus Medical University, Salzburg, Austria
| | | | - W Sperl
- Children's Hospital, Paracelsus Medical University, Salzburg, Austria
| | - P Pietsch
- kbo-Kinderzentrum, Technische Universität München, Germany
| | - B Ertl-Wagner
- Institute for Clinical Radiology, Ludwig-Maximilians-University Munich, Germany
| | - H Bolz
- Bioscientia, Center for Human Genetics, Ingelheim, Germany
| | - C Bergmann
- Bioscientia, Center for Human Genetics, Ingelheim, Germany; Children's University Hospital, Zürich, Switzerland
| | - O Rittinger
- Clinical Genetics Unit, Children's Hospital, Paracelsus Medical University, Salzburg, Austria
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Gagliardi C, Brenna V, Romaniello R, Arrigoni F, Tavano A, Romani M, Valente EM, Borgatti R. Cognitive rehabilitation in a child with Joubert Syndrome: Developmental trends and adaptive changes in a single case report. RESEARCH IN DEVELOPMENTAL DISABILITIES 2015; 47:375-384. [PMID: 26489806 DOI: 10.1016/j.ridd.2015.09.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 09/10/2015] [Accepted: 09/14/2015] [Indexed: 06/05/2023]
Abstract
We report the clinical and rehabilitative follow up of M, a female child carrying a compound heterozygous pathogenic mutations in the TCTN1 gene and affected by Joubert Syndrome (JS). JS is a congenital cerebellar ataxia characterized by "the molar tooth sign" on axial MRI, a pathognomonic neuroradiological malformation involving the cerebellum and brainstem. JS presents with high phenotypic/cognitive variability, and little is known about cognitive rehabilitation programs. We describe the therapeutic settings, intensive rehabilitation targets and outcome indexes in M's cognitive development. Using a single case evidence-based approach, we attempt to distinguish the effectiveness of the intervention from the overall developmental trend. We assume that an adequate amount of focused, goal directed treatment in a relative short period of time can be at least as effective as one provided in longer time, and much less interfering with the child's everyday life. We conclude by discussing specific issues in cognitive development and rehabilitation in JS and, more broadly, in cerebellar malformations.
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Affiliation(s)
- Chiara Gagliardi
- Neuropsychiatry and Neurorehabilitation Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy.
| | - Viola Brenna
- Neuropsychiatry and Neurorehabilitation Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Romina Romaniello
- Neuropsychiatry and Neurorehabilitation Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Filippo Arrigoni
- Neuroimaging Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Alessandro Tavano
- Department of Neuroscience, Max Planck Institute for Empirical Aesthetics, Frankfurt am Main, Germany
| | - Marta Romani
- IRCCS Casa Sollievo della Sofferenza, Mendel Laboratory, San Giovanni Rotondo, Italy
| | - Enza Maria Valente
- Section of Neurosciences, Department of Medicine and Surgery, University of Salerno, Salerno, Italy
| | - Renato Borgatti
- Neuropsychiatry and Neurorehabilitation Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
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25
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Knopp C, Rudnik-Schöneborn S, Eggermann T, Bergmann C, Begemann M, Schoner K, Zerres K, Ortiz Brüchle N. Syndromic ciliopathies: From single gene to multi gene analysis by SNP arrays and next generation sequencing. Mol Cell Probes 2015; 29:299-307. [DOI: 10.1016/j.mcp.2015.05.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 05/13/2015] [Accepted: 05/19/2015] [Indexed: 01/23/2023]
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26
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Cortés CR, Metzis V, Wicking C. Unmasking the ciliopathies: craniofacial defects and the primary cilium. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2015; 4:637-53. [PMID: 26173831 DOI: 10.1002/wdev.199] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 05/19/2015] [Accepted: 05/30/2015] [Indexed: 12/29/2022]
Abstract
Over the past decade, the primary cilium has emerged as a pivotal sensory organelle that acts as a major signaling hub for a number of developmental signaling pathways. In that time, a vast number of proteins involved in trafficking and signaling have been linked to ciliary assembly and/or function, demonstrating the importance of this organelle during embryonic development. Given the central role of the primary cilium in regulating developmental signaling, it is not surprising that its dysfunction results in widespread defects in the embryo, leading to an expanding class of human congenital disorders known as ciliopathies. These disorders are individually rare and phenotypically variable, but together they affect virtually every vertebrate organ system. Features of ciliopathies that are often overlooked, but which are being reported with increasing frequency, are craniofacial abnormalities, ranging from subtle midline defects to full-blown orofacial clefting. The challenge moving forward is to understand the primary mechanism of disease given the link between the primary cilium and a number of developmental signaling pathways (such as hedgehog, platelet-derived growth factor, and WNT signaling) that are essential for craniofacial development. Here, we provide an overview of the diversity of craniofacial abnormalities present in the ciliopathy spectrum, and reveal those defects in common across multiple disorders. Further, we discuss the molecular defects and potential signaling perturbations underlying these anomalies. This provides insight into the mechanisms leading to ciliopathy phenotypes more generally and highlights the prevalence of widespread dysmorphologies resulting from cilia dysfunction.
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Affiliation(s)
- Claudio R Cortés
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Vicki Metzis
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Carol Wicking
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
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Jia Y, Wang Y, Xie J. The Hedgehog pathway: role in cell differentiation, polarity and proliferation. Arch Toxicol 2015; 89:179-91. [PMID: 25559776 PMCID: PMC4630008 DOI: 10.1007/s00204-014-1433-1] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 12/04/2014] [Indexed: 02/07/2023]
Abstract
Hedgehog (Hh) is first described as a genetic mutation that has "spiked" phenotype in the cuticles of Drosophila in later 1970s. Since then, Hh signaling has been implicated in regulation of differentiation, proliferation, tissue polarity, stem cell population and carcinogenesis. The first link of Hh signaling to cancer was established through discovery of genetic mutations of Hh receptor gene PTCH1 being responsible for Gorlin syndrome in 1996. It was later shown that Hh signaling is associated with many types of cancer, including skin, leukemia, lung, brain and gastrointestinal cancers. Another important milestone for the Hh research field is the FDA approval for the clinical use of Hh inhibitor Erivedge/Vismodegib for treatment of locally advanced and metastatic basal cell carcinomas. However, recent clinical trials of Hh signaling inhibitors in pancreatic, colon and ovarian cancer all failed, indicating a real need for further understanding of Hh signaling in cancer. In this review, we will summarize recent progress in the Hh signaling mechanism and its role in human cancer.
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Affiliation(s)
- Yanfei Jia
- Central Laboratory, Jinan Central Hospital Affiliated to Shandong, University, Jinan, China
- Division of Hematology and Oncology, Department of Pediatrics, Wells Center for Pediatric Research, Indiana University Simon Cancer Center, Indiana University, Indianapolis, IN 46202, USA
| | - Yunshan Wang
- Central Laboratory, Jinan Central Hospital Affiliated to Shandong, University, Jinan, China
| | - Jingwu Xie
- Division of Hematology and Oncology, Department of Pediatrics, Wells Center for Pediatric Research, Indiana University Simon Cancer Center, Indiana University, Indianapolis, IN 46202, USA
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