1
|
Chung DD, Chen AC, Choo CH, Zhang W, Williams D, Griffis CG, Bonezzi P, Jatavallabhula K, Sampath AP, Aldave AJ. Investigation of the functional impact of CHED- and FECD4-associated SLC4A11 mutations in human corneal endothelial cells. PLoS One 2024; 19:e0296928. [PMID: 38252645 PMCID: PMC10802951 DOI: 10.1371/journal.pone.0296928] [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: 09/11/2023] [Accepted: 12/22/2023] [Indexed: 01/24/2024] Open
Abstract
Mutations in the solute linked carrier family 4 member 11 (SLC4A11) gene are associated with congenital hereditary endothelial dystrophy (CHED) and Fuchs corneal endothelial dystrophy type 4 (FECD4), both characterized by corneal endothelial cell (CEnC) dysfunction and/or cell loss leading to corneal edema and visual impairment. In this study, we characterize the impact of CHED-/FECD4-associated SLC4A11 mutations on CEnC function and SLC4A11 protein localization by generating and comparing human CEnC (hCEnC) lines expressing wild type SLC4A11 (SLC4A11WT) or mutant SLC4A11 harboring CHED-/FECD4-associated SLC4A11 mutations (SLC4A11MU). SLC4A11WT and SLC4A11MU hCEnC lines were generated to express either SLC4A11 variant 2 (V2WT and V2MU) or variant 3 (V3WT and V3MU), the two major variants expressed in ex vivo hCEnC. Functional assays were performed to assess cell barrier, proliferation, viability, migration, and NH3-induced membrane conductance. We demonstrate SLC4A11-/- and SLC4A11MU hCEnC lines exhibited increased migration rates, altered proliferation and decreased cell viability compared to SLC4A11WT hCEnC. Additionally, SLC4A11-/- hCEnC demonstrated decreased cell-substrate adhesion and membrane capacitances compared to SLC4A11WT hCEnC. Induction with 10mM NH4Cl led SLC4A11WT hCEnC to depolarize; conversely, SLC4A11-/- hCEnC hyperpolarized and the majority of SLC4A11MU hCEnC either hyperpolarized or had minimal membrane potential changes following NH4Cl induction. Immunostaining of primary hCEnC and SLC4A11WT hCEnC lines for SLC4A11 demonstrated predominately plasma membrane staining with poor or partial colocalization with mitochondrial marker COX4 within a subset of punctate subcellular structures. Overall, our findings suggest CHED-associated SLC4A11 mutations likely lead to hCEnC dysfunction, and ultimately CHED, by interfering with cell migration, proliferation, viability, membrane conductance, barrier function, and/or cell surface localization of the SLC4A11 protein in hCEnC. Additionally, based on their similar subcellular localization and exhibiting similar cell functional profiles, protein isoforms encoded by SLC4A11 variant 2 and variant 3 likely have highly overlapping functional roles in hCEnC.
Collapse
Affiliation(s)
- Doug D. Chung
- Department of Ophthalmology, Stein Eye Institute at UCLA, Los Angeles, California, United States of America
| | - Angela C. Chen
- Department of Ophthalmology, Stein Eye Institute at UCLA, Los Angeles, California, United States of America
| | - Charlene H. Choo
- Department of Ophthalmology, Stein Eye Institute at UCLA, Los Angeles, California, United States of America
| | - Wenlin Zhang
- Department of Ophthalmology, Stein Eye Institute at UCLA, Los Angeles, California, United States of America
| | - Dominic Williams
- Department of Ophthalmology, Stein Eye Institute at UCLA, Los Angeles, California, United States of America
| | - Christopher G. Griffis
- Department of Ophthalmology, Stein Eye Institute at UCLA, Los Angeles, California, United States of America
| | - Paul Bonezzi
- Department of Ophthalmology, Stein Eye Institute at UCLA, Los Angeles, California, United States of America
| | - Kavya Jatavallabhula
- Department of Ophthalmology, Stein Eye Institute at UCLA, Los Angeles, California, United States of America
| | - Alapakkam P. Sampath
- Department of Ophthalmology, Stein Eye Institute at UCLA, Los Angeles, California, United States of America
| | - Anthony J. Aldave
- Department of Ophthalmology, Stein Eye Institute at UCLA, Los Angeles, California, United States of America
| |
Collapse
|
2
|
Oie Y, Yamaguchi T, Nishida N, Okumura N, Maeno S, Kawasaki R, Jhanji V, Shimazaki J, Nishida K. Systematic Review of the Diagnostic Criteria and Severity Classification for Fuchs Endothelial Corneal Dystrophy. Cornea 2023; 42:1590-1600. [PMID: 37603692 DOI: 10.1097/ico.0000000000003343] [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: 12/27/2022] [Accepted: 05/28/2023] [Indexed: 08/23/2023]
Abstract
PURPOSE There are no defined diagnostic criteria and severity classification for Fuchs endothelial corneal dystrophy (FECD), which are required for objective standardized assessments. Therefore, we performed a systematic literature review of the current diagnosis and severity classification of FECD. METHODS We searched the Ovid MEDLINE and Web of Science databases for studies published until January 13, 2021. We excluded review articles, conference abstracts, editorials, case reports with <5 patients, and letters. RESULTS Among 468 articles identified, we excluded 173 and 165 articles in the first and second screenings, respectively. Among the 130 included articles, 61 (47%) and 99 (76%) mentioned the diagnostic criteria for FECD and described its severity classification, respectively. Regarding diagnosis, slitlamp microscope alone was the most frequently used device in 31 (51%) of 61 articles. Regarding diagnostic findings, corneal guttae alone was the most common parameter [adopted in 23 articles (38%)]. Regarding severity classification, slitlamp microscopes were used in 88 articles (89%). The original or modified Krachmer grading scale was used in 77 articles (78%), followed by Adami's classification in six (6%). Specular microscopes or Scheimpflug tomography were used in four articles (4%) and anterior segment optical coherence tomography in one (1%). CONCLUSIONS FECD is globally diagnosed by the corneal guttae using slitlamp examination, and its severity is predominantly determined by the original or modified Krachmer grading scale. Objective severity grading using Scheimpflug or anterior segment optical coherence tomography can be applied in the future innovative therapies such as cell injection therapy or novel small molecules.
Collapse
Affiliation(s)
- Yoshinori Oie
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Takefumi Yamaguchi
- Department of Ophthalmology, Tokyo Dental College Ichikawa General Hospital, Ichikawa, Japan
| | - Nozomi Nishida
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Naoki Okumura
- Department of Biomedical Engineering, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Japan; and
| | - Sayo Maeno
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Ryo Kawasaki
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Vishal Jhanji
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Jun Shimazaki
- Department of Ophthalmology, Tokyo Dental College Ichikawa General Hospital, Ichikawa, Japan
| | - Kohji Nishida
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Japan
| |
Collapse
|
3
|
Tsedilina TR, Sharova E, Iakovets V, Skorodumova LO. Systematic review of SLC4A11, ZEB1, LOXHD1, and AGBL1 variants in the development of Fuchs' endothelial corneal dystrophy. Front Med (Lausanne) 2023; 10:1153122. [PMID: 37441688 PMCID: PMC10333596 DOI: 10.3389/fmed.2023.1153122] [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: 01/28/2023] [Accepted: 03/30/2023] [Indexed: 07/15/2023] Open
Abstract
Introduction The pathogenic role of variants in TCF4 and COL8A2 in causing Fuchs' endothelial corneal dystrophy (FECD) is not controversial and has been confirmed by numerous studies. The causal role of other genes, SLC4A11, ZEB1, LOXHD1, and AGBL1, which have been reported to be associated with FECD, is more complicated and less obvious. We performed a systematic review of the variants in the above-mentioned genes in FECD cases, taking into account the currently available population frequency information, transcriptomic data, and the results of functional studies to assess their pathogenicity. Methods Search for articles published in 2005-2022 was performed manually between July 2022 and February 2023. We searched for original research articles in peer-reviewed journals, written in English. Variants in the genes of interest identified in patients with FECD were extracted for the analysis. We classified each presented variant by pathogenicity status according to the ACMG criteria implemented in the Varsome tool. Diagnosis, segregation data, presence of affected relatives, functional analysis results, and gene expression in the corneal endothelium were taken into account. Data on the expression of genes of interest in the corneal endothelium were extracted from articles in which transcriptome analysis was performed. The identification of at least one variant in a gene classified as pathogenic or significantly associated with FECD was required to confirm the causal role of the gene in FECD. Results The analysis included 34 articles with 102 unique ZEB1 variants, 20 articles with 64 SLC4A11 variants, six articles with 26 LOXHD1 variants, and five articles with four AGBL1 variants. Pathogenic status was confirmed for seven SLC4A11 variants found in FECD. No variants in ZEB1, LOXHD1, and AGBL1 genes were classified as pathogenic for FECD. According to the transcriptome data, AGBL1 and LOXHD1 were not expressed in the corneal endothelium. Functional evidence for the association of LOXHD1, and AGBL1 with FECD was conflicting. Conclusion Our analysis confirmed the causal role of SLC4A11 variants in the development of FECD. The causal role of ZEB1, LOXHD1, and AGBL1 variants in FECD has not been confirmed. Further evidence from familial cases and functional analysis is needed to confirm their causal roles in FECD.
Collapse
Affiliation(s)
- Tatiana Romanovna Tsedilina
- Laboratory of Human Molecular Genetics, Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, Russia
| | - Elena Sharova
- Laboratory of Human Molecular Genetics, Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, Russia
| | - Valeriia Iakovets
- Laboratory of Human Molecular Genetics, Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, Russia
- I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Liubov Olegovna Skorodumova
- Laboratory of Human Molecular Genetics, Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, Russia
| |
Collapse
|
4
|
Viberg A, Westin IM, Golovleva I, Byström B. TCF4 trinucleotide repeat expansion in Swedish cases with Fuchs' endothelial corneal dystrophy. Acta Ophthalmol 2021; 100:541-548. [PMID: 34644448 DOI: 10.1111/aos.15032] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 09/22/2021] [Indexed: 12/27/2022]
Abstract
PURPOSE Fuchs' endothelial corneal dystrophy (FECD) has been considered a genetically heterogeneous disease but is increasingly associated with the transcription factor 4 (TCF4) gene. This study investigates the prevalence of the cytosine-thymine-guanine (CTG)n repeat expansion in TCF4 among FECD patients in northern Sweden coupled to the phenotype. METHODS Blood samples were collected from 85 FECD cases at different stages. Short tandem repeat PCR and triplet repeat-primed PCR were applied in order to determine TCF4 (CTG)n genotype. RESULTS A (CTG)n repeat expansion (n > 50) in TCF4 was identified in 76 of 85 FECD cases (89.4%) and in four of 102 controls (3.9%). The median (CTG)n repeat length was 81 (IQR 39.3) in mild FECD and 87 (IQR 13.0) in severe FECD (p = 0.01). A higher number of (CTG)n repeats in an expanded TCF4 allele increased the probability of severe FECD. Other ocular surgery was overrepresented in FECD cases without a (CTG)n repeat expansion (44.4%, n = 4) compared with 3.9% (n = 3) in FECD cases with an (CTG)n repeat expansion (p < 0.001). CONCLUSION In northern Sweden, the FECD phenotype is associated with (CTG)n expansion in the TCF4 gene, with nearly 90% of patients being hetero- or homozygous for (CTG)n expansion over 50 repeats. Furthermore, the severity of FECD was associated with the repeat length in the TCF4 gene. Ocular surgery might act as an environmental factor explaining the clinical disease in FECD without a repeat expansion in TCF4.
Collapse
Affiliation(s)
- Andreas Viberg
- Department of Clinical Sciences/Ophthalmology Umeå University Umeå Sweden
| | - Ida Maria Westin
- Department of Medical Biosciences/Medical and Clinical Genetics Umeå University Umeå Sweden
| | - Irina Golovleva
- Department of Medical Biosciences/Medical and Clinical Genetics Umeå University Umeå Sweden
| | - Berit Byström
- Department of Clinical Sciences/Ophthalmology Umeå University Umeå Sweden
| |
Collapse
|
5
|
Liu X, Zheng T, Zhao C, Zhang Y, Liu H, Wang L, Liu P. Genetic mutations and molecular mechanisms of Fuchs endothelial corneal dystrophy. EYE AND VISION 2021; 8:24. [PMID: 34130750 PMCID: PMC8204469 DOI: 10.1186/s40662-021-00246-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 05/18/2021] [Indexed: 11/10/2022]
Abstract
Background Fuchs endothelial corneal dystrophy is a hereditary disease and the most frequent cause of corneal transplantation in the worldwide. Its main clinical signs are an accelerated decrease in the number of endothelial cells, thickening of Descemet’s membrane and formation of guttae in the extracellular matrix. The cornea’s ability to maintain stromal dehydration is impaired, causing painful epithelial bullae and loss of vision at the point when the amount of corneal endothelial cells cannot be compensated. At present, apart from corneal transplantation, there is no other effective treatment that prevents blindness. Main text In this review, we first summarized the mutations of COL8A2, TCF4, TCF8, SLC4A11 and AGBL1 genes in Fuchs endothelial corneal dystrophy. The molecular mechanisms associated with Fuchs endothelial corneal dystrophy, such as endoplasmic reticulum stress and unfolded protein response pathway, oxidative stress, mitochondrial dysregulation pathway, apoptosis pathway, mitophagy, epithelial-mesenchymal transition pathway, RNA toxicity and repeat-associated non-ATG translation, and other pathogenesis, were then explored. Finally, we discussed several potential treatments related to the pathogenesis of Fuchs endothelial corneal dystrophy, which may be the focus of future research. Conclusions The pathogenesis of Fuchs endothelial corneal dystrophy is very complicated. Currently, corneal transplantation is an important method in the treatment of Fuchs endothelial corneal dystrophy. It is necessary to continuously explore the pathogenesis of Fuchs endothelial corneal dystrophy and establish the scientific foundations for the development of next-generation corneal therapeutics.
Collapse
Affiliation(s)
- Xuerui Liu
- Department of Ophthalmology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Tao Zheng
- Department of Ophthalmology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Chuchu Zhao
- Department of Ophthalmology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Yi Zhang
- Department of Ophthalmology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Hanruo Liu
- The Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Liyuan Wang
- Department of Ophthalmology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China.
| | - Ping Liu
- Department of Ophthalmology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China.
| |
Collapse
|
6
|
Walckling M, Waterstradt R, Baltrusch S. Collagen Remodeling Plays a Pivotal Role in Endothelial Corneal Dystrophies. Invest Ophthalmol Vis Sci 2021; 61:1. [PMID: 33259606 PMCID: PMC7718819 DOI: 10.1167/iovs.61.14.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Purpose To elucidate the collagen structure in the Descemet membrane (DM) of the human cornea and to characterize its rearrangement in patients with endothelial corneal dystrophies. Methods Corneas from nine human donors and dystrophic DMs removed from 16 affected eyes of 13 patients by endothelial keratoplasty (DMEK) were investigated using a correlative RT-qPCR and label-free two-channel multiphoton microscopy (MPM) setup. Although collagen formation was visualized by second harmonic generation, the cellular structure was determined by autofluorescence. Results The DM of the human donor cornea was characterized by a consistent pattern of fine hexagonal collagen structures that form a supportive scaffold for the endothelial cells. Accordingly, network-forming collagens (8A1 and 8A2) but less fibrillar collagens (only 1A2) were expressed. DMEK resulted in significant (P < 0.0001) improvement of best-corrected visual acuity. In the removed dystrophic DMs, MPM analyses revealed collagen rearrangement in addition to loss of endothelial cells and the development of guttae. MPM analyses of the whole patient's DM demonstrated this collagen remodeling in its entirety and facilitated correlation to Scheimpflug corneal tomography. In most DMs a unique honeycomb collagen network was identified, with distinct bundles surrounding the guttae and correlating with expression of fibrillar collagens (1A1). Conversely, some DMs showed either reduced collagen on MPM and RT-qPCR analysis or diffuse thickening and storage of extracellular matrix. Conclusions The collagen structure of the DM and its adaptive remodeling in endothelial corneal dystrophies has been characterized for the first time here and will facilitate individual therapeutic approaches.
Collapse
Affiliation(s)
- Marcus Walckling
- Department of Ophthalmology, University Medicine Rostock, Rostock, Germany
| | - Rica Waterstradt
- Institute of Medical Biochemistry and Molecular Biology, University Medicine Rostock, Rostock, Germany
| | - Simone Baltrusch
- Institute of Medical Biochemistry and Molecular Biology, University Medicine Rostock, Rostock, Germany.,Department Life, Light & Matter, University of Rostock, Rostock, Germany
| |
Collapse
|
7
|
Abstract
As a transparent avascular tissue located at the front of the eyeball, the cornea is an important barrier to external damage. Both epithelial and endothelial cells of the cornea harbor primary cilia, which sense changes in the external environment and regulate intracellular signaling pathways. Accumulating evidence suggests that the primary cilium regulates corneal development in several ways, including participation in corneal epithelial stratification and maintenance of corneal endothelial cell morphology. In addition, the primary cilium has been implicated in the pathogenesis of several corneal diseases. In this review, we discuss recent findings that demonstrate the critical role of the primary cilium in corneal development. We also discuss the link between ciliary dysfunction and corneal diseases, which suggests that the primary cilium could be targeted to treat these diseases.
Collapse
Affiliation(s)
- Ting Song
- Institute of Biomedical Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan, Shandong 250014, China
| | - Jun Zhou
- Institute of Biomedical Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan, Shandong 250014, China.,State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, China. E-mail:
| |
Collapse
|
8
|
Zhou K, Huang L, Feng M, Li X, Zhao Y, Liu F, Wei J, Qin D, Lu Q, Shi M, Qu S, Tang F. A novel SLC26A4 splicing mutation identified in two deaf Chinese twin sisters with enlarged vestibular aqueducts. Mol Genet Genomic Med 2020; 8:e1447. [PMID: 32770655 PMCID: PMC7549568 DOI: 10.1002/mgg3.1447] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 07/15/2020] [Accepted: 07/16/2020] [Indexed: 12/13/2022] Open
Abstract
Background Variants in the SLC26A4 gene are correlated with nonsyndromic hearing loss with an enlarged vestibular aqueduct (EVA). This study aimed to identify the genetic causes in a Chinese family with EVA, and the pathogenicity of the detected variants. Methods We collected blood samples and clinical data from a pair of deaf twin sisters with EVA and their family members. As controls, a group of 500 normal‐hearing people were enrolled in our study. Twenty‐one exons and flanking splice sites of the SLC26A4 gene were screened for pathogenic mutations by polymerase chain reaction and bidirectional Sanger sequencing. Minigene assays were used to verify whether the novel SLC26A4 intronic mutation influenced the normal splicing of mRNA. Results Hearing loss in the twins with EVA was diagnosed using auditory tests and imaging examinations. Two pathogenic mutations, c.919‐2A>G and c.1614+5G>A were detected in SLC26A4, the latter of which has not been reported in the literature. The minigene expression in vitro confirmed that c.1614+5G>A could cause aberrant splicing, resulting in skipping over exon 14. Conclusions On the SLC26A4 gene, c.1614+5G>A is a pathogenic mutation. This finding enriches the mutational spectrum of the SLC26A4 gene and provides a basis for the genetic diagnosis of EVA.
Collapse
Affiliation(s)
- Kai Zhou
- Department of Otolaryngology & Head and Neck, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China.,Guangxi Medical University, Nanning, Guangxi, China
| | - Lancheng Huang
- Department of Otolaryngology & Head and Neck, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China.,Guangxi Medical University, Nanning, Guangxi, China
| | - Menglong Feng
- Department of Otolaryngology & Head and Neck, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China.,Guangxi University of Chinese Medicine, Nanning, Guangxi, China
| | - Xinlei Li
- Medical Genetics Center, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Yi Zhao
- Medical Genetics Center, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Fei Liu
- Research Center of Medical Sciences, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Jiazhang Wei
- Department of Otolaryngology & Head and Neck, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Danxue Qin
- Department of Otolaryngology & Head and Neck, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Qiutian Lu
- Department of Otolaryngology & Head and Neck, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Min Shi
- Department of Otolaryngology & Head and Neck, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Shenhong Qu
- Department of Otolaryngology & Head and Neck, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Fengzhu Tang
- Department of Otolaryngology & Head and Neck, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| |
Collapse
|
9
|
Five Novel Mutations in LOXHD1 Gene Were Identified to Cause Autosomal Recessive Nonsyndromic Hearing Loss in Four Chinese Families. BIOMED RESEARCH INTERNATIONAL 2020; 2020:1685974. [PMID: 32149082 PMCID: PMC7049443 DOI: 10.1155/2020/1685974] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 01/17/2020] [Indexed: 01/31/2023]
Abstract
Hearing loss is one of the most common sensory disorders in newborns and is mostly caused by genetic factors. Autosomal recessive nonsyndromic hearing loss (ARNSHL) is usually characterized as a severe-to-profound congenital sensorineural hearing loss and later can cause various degrees of defect in the language and intelligent development of newborns. The mutations in LOXHD1 gene have been shown to cause DFNB77, a type of ARNSHL. To date, there are limited reports about the association between LOXHD1 gene and ARNSHL. In this study, we reported six patients from four Chinese families suffering from severe-to-profound nonsyndromic hearing loss. We performed targeted next generation sequencing in the six affected members and identified five novel pathogenic mutations in LOXHD1 including c.277G>A (p.D93N), c.611-2A>T, c.1255+3A>G, c.2329C>T (p.Q777 ∗ ), and c.5888delG (p.G1963Afs ∗ 136). These mutations were confirmed to be cosegregated with the hearing impairment in the families by Sanger sequencing and were inherited in an autosomal recessive pattern. All of the five mutations were absent in 200 control subjects. There were no symptoms of Fuchs corneal dystrophy in the probands and their blood-related relatives. We concluded that these five novel mutations could be involved in the underlying mechanism resulting in the hearing loss, and this discovery expands the genotypic spectrum of LOXHD1 mutations.
Collapse
|
10
|
Shen N, Wang T, Li D, Liu A, Lu Y. Whole-exome sequencing identifies a novel missense variant within LOXHD1 causing rare hearing loss in a Chinese family. BMC MEDICAL GENETICS 2019; 20:30. [PMID: 30760222 PMCID: PMC6373029 DOI: 10.1186/s12881-019-0758-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 01/22/2019] [Indexed: 11/10/2022]
Abstract
Background Deafness, autosomal recessive 77 (DFNB77) is a rare non-syndromic hearing loss (NSHL) worldwide, which is caused by deleterious variants within lipoxygenase homology domains 1 (LOXHD1). Here we identified that a novel missense variant of LOXHD1 was associated with NSHL in a Chinese family under consanguineous marriage. Case presentation A 28-year-old woman suffered a bilateral profound NSHL. Impedance audiometry, temporal bone computerized tomography (TBCT) scans and magnetic resonance imaging-inner ear hydrography (MRI-IEH) did not find any obvious abnormality of middle or inner ear. Routine genetic detection did not find pathogenic variants in common HL-associated genes. Therefore, we performed a whole-exome sequencing (WES) in this family. By trio-WES, co-segregation validation and bioinformatics analysis, we revealed that a novel homozygous variant in this patient, LOXHD1: c.5948C > T (p.S1983F), might be the pathogenic factor. Her parents (heterozygotes) and brother (wild-type) were asymptomatic. Conclusions We successfully identified a novel variant of LOXHD1 associated with a rare NSHL from a Chinese family. Our finds highlight the effectiveness of trio-WES for molecular diagnosis of rare NHSL, and expand the genotypic spectrum of DFNB77. Electronic supplementary material The online version of this article (10.1186/s12881-019-0758-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Na Shen
- Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Ting Wang
- Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Delei Li
- Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Aiguo Liu
- Department of Otorhinolaryngology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Yanjun Lu
- Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| |
Collapse
|
11
|
Rao BS, Ansar S, Arokiasamy T, Sudhir RR, Umashankar V, Rajagopal R, Soumittra N. Analysis of candidate genes ZEB1 and LOXHD1 in late-onset Fuchs' endothelial corneal dystrophy in an Indian cohort. Ophthalmic Genet 2018; 39:443-449. [PMID: 29799290 DOI: 10.1080/13816810.2018.1474367] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
BACKGROUND Fuchs' endothelial corneal dystrophy (FECD) is a complex degenerative disease of the corneal endothelium with genetic predisposition. Pathogenic rare variants have been identified in SLC4A11, LOXHD1, ZEB1, and AGBL1. Association of single nucleotide polymorphisms (SNPs) and CTG trinucleotide repeat expansions in the intron of TCF4 gene to FECD has been studied across multiple ethnicities. Recently, genome-wide association studies have also identified KANK4, LAMC1, and ATP1B1 as novel loci for FECD. Here, we report the contribution of ZEB1 and LOXHD1 genes in our sporadic late-onset FECD cohort. MATERIALS AND METHODS In the experimental study, coding regions of ZEB1 and LOXHD1 were screened by Sanger DNA sequencing in 52 late-onset and 5 early-onset FECD cases of Indian origin, recruited at a tertiary eye care center. Further, bioinformatics analysis was done. RESULTS One reported missense mutation, c.2522A>C; p.(Q841P), and one variant of uncertain significance (VUS), c.619A>G; p.(S207G), were identified in the ZEB1 gene. One VUS, c.6413G>Ap.(R2138Q), was observed in LOXHD1. A 3D structural bioinformatic analysis of the missense variant in LOXHD1 predicted the variant to affect the structure-function relationship of the protein. DISCUSSION While mutations in ZEB1 contributed to 2% of the late-onset FECD cases, the exact role of the two VUS identified in ZEB1 and LOXHD1 in FECD pathogenesis needs to be studied.
Collapse
Affiliation(s)
- Bhavna S Rao
- a School of Biotechnology , SASTRA University , Thanjavur , India.,b SNONGC Department of Genetics and Molecular Biology , Vision Research Foundation , Chennai , India
| | - Samdani Ansar
- a School of Biotechnology , SASTRA University , Thanjavur , India.,c Department of Bioinformatics , Vision Research Foundation , Chennai , India
| | - Tharigopala Arokiasamy
- b SNONGC Department of Genetics and Molecular Biology , Vision Research Foundation , Chennai , India
| | | | - Vetrivel Umashankar
- c Department of Bioinformatics , Vision Research Foundation , Chennai , India
| | - Rama Rajagopal
- d Cornea Services , Medical Research Foundation , Chennai , India
| | - Nagasamy Soumittra
- b SNONGC Department of Genetics and Molecular Biology , Vision Research Foundation , Chennai , India
| |
Collapse
|