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Dasgupta S, Hong J, Morris R, Iqbal J, Lennox-Bowley A, Saniasiaya J. X-Linked Gusher Disease DFNX2 in Children, a Rare Inner Ear Dysplasia with Mixed Hearing and Vestibular Loss. Audiol Res 2023; 13:600-614. [PMID: 37622928 PMCID: PMC10451158 DOI: 10.3390/audiolres13040052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 07/19/2023] [Accepted: 07/26/2023] [Indexed: 08/26/2023] Open
Abstract
Conductive hearing losses are typically present in disorders of the external/middle ear. However, there is a rare group of inner ear conditions called third windows that can also generate a conductive hearing loss. This is due to an abnormal connection between the middle and the inner ear or between the inner ear and the cranial cavity. X-linked gusher disorder is an extremely rare congenital inner ear dysplastic syndrome with an abnormal connection due to a characteristic incomplete cochlear partition type III and an incomplete internal auditory meatus fundus. The disorder is inherited in an X-linked fashion due to the mutation of the POU3F4 gene. We present two siblings diagnosed with the condition and their long-term follow-ups. They both presented audiovestibular symptoms and showed progressive mixed losses and bilateral vestibular weakness. They were treated with cochlear implant, digital amplification and with vestibular rehabilitation. Significant others around them were involved in their journey with the medical team, and in both, a very favourable outcome was achieved. This is the first time that we have reported evolving audiovestibular function with vestibular quantification in X-linked gusher disorder and emphasize on the multidisciplinary holistic approach to manage these children effectively.
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Affiliation(s)
- Soumit Dasgupta
- Alder Hey Children’s Hospital NHS Foundation Trust, Eaton Road, Liverpool L14 5AB, UK
- Faculty of Health and Medical Sciences, University of Liverpool, Liverpool L69 3BX, UK; (J.H.); (R.M.)
| | - James Hong
- Faculty of Health and Medical Sciences, University of Liverpool, Liverpool L69 3BX, UK; (J.H.); (R.M.)
| | - Rhyanna Morris
- Faculty of Health and Medical Sciences, University of Liverpool, Liverpool L69 3BX, UK; (J.H.); (R.M.)
| | - Javed Iqbal
- East Lancashire Hospitals NHS Trust, Burnley BB10 2PQ, UK;
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Zhang J, Guan J, Wang Q. [Genetics of pediatric hearing loss]. LIN CHUANG ER BI YAN HOU TOU JING WAI KE ZA ZHI = JOURNAL OF CLINICAL OTORHINOLARYNGOLOGY, HEAD, AND NECK SURGERY 2023; 37:181-185. [PMID: 36843515 PMCID: PMC10320671 DOI: 10.13201/j.issn.2096-7993.2023.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Indexed: 02/28/2023]
Abstract
With the rapid development of sequencing technology and bioinformatics, the genetic research and related clinical practice of pediatric hearing loss have also made significant progress. This review summarized and analyzed the genetic causes of hearing impairment in children and the research progress of related genetic diagnosis and screening, in order to provide reference for the prevention and treatment of pediatric hearing loss and related research.
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Affiliation(s)
- Jiao Zhang
- Department of Audiology and Vestibular Medicine,Institute of Otolaryngology,Senior Department of Otolaryngology Head and Neck Surgery,the Sixth Medical Center of Chinese PLA General Hospital,National Clinical Research Center for Otolaryngologic Diseases,Beijing,100048,China
| | - Jing Guan
- Department of Otolaryngology Head and Neck Surgery,the First Medical Center of Chinese PLA General Hospital
| | - Qiuju Wang
- Department of Audiology and Vestibular Medicine,Institute of Otolaryngology,Senior Department of Otolaryngology Head and Neck Surgery,the Sixth Medical Center of Chinese PLA General Hospital,National Clinical Research Center for Otolaryngologic Diseases,Beijing,100048,China
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Defourny J. Considering gene therapy to protect from X-linked deafness DFNX2 and associated neurodevelopmental disorders. IBRAIN 2022; 8:431-441. [PMID: 37786584 PMCID: PMC10529175 DOI: 10.1002/ibra.12068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 08/10/2022] [Accepted: 09/13/2022] [Indexed: 10/04/2023]
Abstract
Mutations and deletions in the gene or upstream of the gene encoding the POU3F4 transcription factor cause X-linked progressive deafness DFNX2 and additional neurodevelopmental disorders in humans. Hearing loss can be purely sensorineural or mixed, that is, with both conductive and sensorineural components. Affected males show anatomical abnormalities of the inner ear, which are jointly defined as incomplete partition type III. Current approaches to improve hearing and speech skills of DFNX2 patients do not seem to be fully effective. Owing to inner ear malformations, cochlear implantation is surgically difficult and may predispose towards severe complications. Even in cases where implantation is safely performed, hearing and speech outcomes remain highly variable among patients. Mouse models for DFNX2 deafness revealed that sensorineural loss could arise from a dysfunction of spiral ligament fibrocytes in the lateral wall of the cochlea, which leads to reduced endocochlear potential. Highly positive endocochlear potential is critical for sensory hair cell mechanotransduction and hearing. In this context, here, we propose to develop a therapeutic approach in male Pou3f4 -/y mice based on an adeno-associated viral (AAV) vector-mediated gene transfer in cochlear spiral ligament fibrocytes. Among a broad range of AAV vectors, AAV7 was found to show a strong tropism for the spiral ligament. Thus, we suggest that an AAV7-mediated delivery of Pou3f4 complementary DNA in the spiral ligament of Pou3f4 -/y mice could represent an attractive strategy to prevent fibrocyte degeneration and to restore normal cochlear functions and properties, including a positive endocochlear potential, before hearing loss progresses to profound deafness.
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Affiliation(s)
- Jean Defourny
- GIGA‐Neurosciences, Unit of Cell and Tissue BiologyUniversity of Liège, C.H.U. B36LiègeBelgium
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Study of complex structural variations of X-linked deafness-2 based on single-molecule sequencing. Biosci Rep 2021; 41:228372. [PMID: 33860785 PMCID: PMC8193640 DOI: 10.1042/bsr20203740] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 03/21/2021] [Accepted: 03/31/2021] [Indexed: 12/16/2022] Open
Abstract
X-linked deafness-2 (DFNX2) is cochlear incomplete partition type III (IP-III), one of inner ear malformations characterized by an abnormally wide opening in the bone separating the basal turn of the cochlea from the internal auditory canal, fixation of the stapes and cerebrospinal fluid (CSF) gusher upon stapedectomy or cochleostomy. The causative gene of DFNX2 was POU3F4. To investigate the genetic causes of DFNX2 and compare the efficiency of different sequencing methods, 12 unrelated patients were enrolled in the present study. Targeted next-generation sequencing (NGS) and long-read sequencing were used to analyze the genetic etiology of DFNX2. Six variants of POU3F4 were identified in this cohort by NGS. Three patients with a negative diagnosis based on NGS were enrolled in further long-read sequencing. Two of them were all found to carry structural variations (SVs) on chromosome X, consisting of an 870-kb deletion (DEL) at upstream of POU3F4 and an 8-Mb inversion (INV). The 870-kb DEL may have been due to non-homologous end joining (NHEJ), while non-allelic homologous recombination (NAHR) within a single chromatid may have accounted for the 8-Mb INV. Common POU3F4 mutations in DFNX2 included point mutations, small insertions and deletions (INDELs), and exon mutations, which can be detected by Sanger sequencing and NGS. Single-molecule long-read sequencing constitutes an additional and valuable method for accurate detection of pathogenic SVs in IP-III patients with negative NGS results.
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Safka Brozkova D, Uhrova Meszarosova A, Lassuthova P, Varga L, Staněk D, Borecká S, Laštůvková J, Čejnová V, Rašková D, Lhota F, Gašperíková D, Seeman P. The Cause of Hereditary Hearing Loss in GJB2 Heterozygotes-A Comprehensive Study of the GJB2/DFNB1 Region. Genes (Basel) 2021; 12:genes12050684. [PMID: 34062854 PMCID: PMC8147375 DOI: 10.3390/genes12050684] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 12/14/2022] Open
Abstract
Hearing loss is a genetically heterogeneous sensory defect, and the frequent causes are biallelic pathogenic variants in the GJB2 gene. However, patients carrying only one heterozygous pathogenic (monoallelic) GJB2 variant represent a long-lasting diagnostic problem. Interestingly, previous results showed that individuals with a heterozygous pathogenic GJB2 variant are two times more prevalent among those with hearing loss compared to normal-hearing individuals. This excess among patients led us to hypothesize that there could be another pathogenic variant in the GJB2 region/DFNB1 locus. A hitherto undiscovered variant could, in part, explain the cause of hearing loss in patients and would mean reclassifying them as patients with GJB2 biallelic pathogenic variants. In order to detect an unknown causal variant, we examined 28 patients using NGS with probes that continuously cover the 0.4 Mb in the DFNB1 region. An additional 49 patients were examined by WES to uncover only carriers. We did not reveal a second pathogenic variant in the DFNB1 region. However, in 19% of the WES-examined patients, the cause of hearing loss was found to be in genes other than the GJB2. We present evidence to show that a substantial number of patients are carriers of the GJB2 pathogenic variant, albeit only by chance.
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Affiliation(s)
- Dana Safka Brozkova
- Neurogenetic laboratory, Department of Paediatric Neurology, 2nd Faculty of Medicine, Charles University and University Hospital Motol, 15006 Prague, Czech Republic; (A.U.M.); (P.L.); (D.S.); (P.S.)
- Correspondence:
| | - Anna Uhrova Meszarosova
- Neurogenetic laboratory, Department of Paediatric Neurology, 2nd Faculty of Medicine, Charles University and University Hospital Motol, 15006 Prague, Czech Republic; (A.U.M.); (P.L.); (D.S.); (P.S.)
| | - Petra Lassuthova
- Neurogenetic laboratory, Department of Paediatric Neurology, 2nd Faculty of Medicine, Charles University and University Hospital Motol, 15006 Prague, Czech Republic; (A.U.M.); (P.L.); (D.S.); (P.S.)
| | - Lukáš Varga
- Department of Otorhinolaryngology–Head and Neck Surgery, Faculty of Medicine and University Hospital, Comenius University, 85107 Bratislava, Slovakia;
- Diabgene Laboratory, Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, 84505 Bratislava, Slovakia; (S.B.); (D.G.)
| | - David Staněk
- Neurogenetic laboratory, Department of Paediatric Neurology, 2nd Faculty of Medicine, Charles University and University Hospital Motol, 15006 Prague, Czech Republic; (A.U.M.); (P.L.); (D.S.); (P.S.)
| | - Silvia Borecká
- Diabgene Laboratory, Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, 84505 Bratislava, Slovakia; (S.B.); (D.G.)
| | - Jana Laštůvková
- Department of Medical Genetics, Masaryk Hospital in Usti nad Labem, Regional Health Corporation, 40011 Ústí nad Labem, Czech Republic; (J.L.); (V.Č.)
| | - Vlasta Čejnová
- Department of Medical Genetics, Masaryk Hospital in Usti nad Labem, Regional Health Corporation, 40011 Ústí nad Labem, Czech Republic; (J.L.); (V.Č.)
| | - Dagmar Rašková
- Centre for Medical Genetics and Reproductive Medicine GENNET, 17000 Prague, Czech Republic; (D.R.); (F.L.)
| | - Filip Lhota
- Centre for Medical Genetics and Reproductive Medicine GENNET, 17000 Prague, Czech Republic; (D.R.); (F.L.)
| | - Daniela Gašperíková
- Diabgene Laboratory, Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, 84505 Bratislava, Slovakia; (S.B.); (D.G.)
| | - Pavel Seeman
- Neurogenetic laboratory, Department of Paediatric Neurology, 2nd Faculty of Medicine, Charles University and University Hospital Motol, 15006 Prague, Czech Republic; (A.U.M.); (P.L.); (D.S.); (P.S.)
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Tekin AM, Matulic M, Wuyts W, Assadi MZ, Mertens G, van Rompaey V, Li Y, van de Heyning P, Topsakal V. A New Pathogenic Variant in POU3F4 Causing Deafness Due to an Incomplete Partition of the Cochlea Paved the Way for Innovative Surgery. Genes (Basel) 2021; 12:genes12050613. [PMID: 33919129 PMCID: PMC8143104 DOI: 10.3390/genes12050613] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/09/2021] [Accepted: 04/11/2021] [Indexed: 12/20/2022] Open
Abstract
Incomplete partition type III (IP-III) is a relatively rare inner ear malformation that has been associated with a POU3F4 gene mutation. The IP-III anomaly is mainly characterized by incomplete separation of the modiolus of the cochlea from the internal auditory canal. We describe a 71-year-old woman with profound sensorineural hearing loss diagnosed with an IP-III of the cochlea that underwent cochlear implantation. Via targeted sequencing with a non-syndromic gene panel, we identified a heterozygous c.934G > C p. (Ala31Pro) pathogenic variant in the POU3F4 gene that has not been reported previously. IP-III of the cochlea is challenging for cochlear implant surgery for two main reasons: liquor cerebrospinalis gusher and electrode misplacement. Surgically, it may be better to opt for a shorter array because it is less likely for misplacement with the electrode in a false route. Secondly, the surgeon has to consider the insertion angles of cochlear access very strictly to avoid misplacement along the inner ear canal. Genetic results in well describes genotype-phenotype correlations are a strong clinical tool and as in this case guided surgical planning and robotic execution.
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Affiliation(s)
- Ahmet M. Tekin
- Department of Otorhinolaryngology, Head and Neck Surgery, Brussels Health Campus, Vrije Universiteit Brussel, 1090 Brussels, Belgium; (A.M.T.); (M.M.)
| | - Marco Matulic
- Department of Otorhinolaryngology, Head and Neck Surgery, Brussels Health Campus, Vrije Universiteit Brussel, 1090 Brussels, Belgium; (A.M.T.); (M.M.)
| | - Wim Wuyts
- Center of Medical Genetics, Faculty of Medicine and Health Sciences, University of Antwerp and Antwerp University Hospital, 2650 Antwerp, Belgium;
| | | | - Griet Mertens
- Department of Otorhinolaryngology, Head and Neck Surgery, Antwerp University Hospital, 2650 Edegem, Belgium; (G.M.); (V.v.R.); (P.v.d.H.)
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, 2610 Antwerp, Belgium
| | - Vincent van Rompaey
- Department of Otorhinolaryngology, Head and Neck Surgery, Antwerp University Hospital, 2650 Edegem, Belgium; (G.M.); (V.v.R.); (P.v.d.H.)
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, 2610 Antwerp, Belgium
| | - Yongxin Li
- Department of Otolaryngology, Head and Neck Surgery, Capital Medical University, Beijing 100730, China;
| | - Paul van de Heyning
- Department of Otorhinolaryngology, Head and Neck Surgery, Antwerp University Hospital, 2650 Edegem, Belgium; (G.M.); (V.v.R.); (P.v.d.H.)
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, 2610 Antwerp, Belgium
| | - Vedat Topsakal
- Department of Otorhinolaryngology, Head and Neck Surgery, Brussels Health Campus, Vrije Universiteit Brussel, 1090 Brussels, Belgium; (A.M.T.); (M.M.)
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital UZ Brussel, Brussels Health Campus, Vrije Universiteit Brussel, 1090 Brussels, Belgium
- Correspondence: ; Tel.: +32-24776882; Fax: +32-24776880
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Wu Y, Zhang X, Wang J, Jin G, Zhang X. Research progress of the transcription factor Brn4 (Review). Mol Med Rep 2021; 23:179. [PMID: 33398372 PMCID: PMC7809911 DOI: 10.3892/mmr.2020.11818] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 11/09/2020] [Indexed: 12/19/2022] Open
Abstract
Brain 4 (Brn4) is a transcription factor belonging to the POU3 family, and it is important for the embryonic development of the neural tube, inner ear and pancreas. In addition, it serves a crucial role in neural stem cell differentiation and reprogramming. The present review aimed to summarize the chromosomal location, species homology, protein molecular structure and tissue distribution of Brn4, in addition to its biological processes, with the aim of providing a reference of its structure and function for further studies, and its potential use as a gene therapy target.
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Affiliation(s)
- Yuying Wu
- Department of Anatomy, Co-Innovation Center of Neuroregeneration, Medical School, Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Xunrui Zhang
- Department of Clinical Medicine, Faculty of Medicine, Xinglin College, Nantong University, Nantong, Jiangsu 226008, P.R. China
| | - Jue Wang
- Department of Anatomy, Co-Innovation Center of Neuroregeneration, Medical School, Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Guohua Jin
- Department of Anatomy, Co-Innovation Center of Neuroregeneration, Medical School, Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Xinhua Zhang
- Department of Anatomy, Co-Innovation Center of Neuroregeneration, Medical School, Nantong University, Nantong, Jiangsu 226001, P.R. China
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Association Between Incomplete Partition Type III and Abnormal Hypothalamic Morphology: Further Imaging Evidence. J Comput Assist Tomogr 2020; 44:704-707. [PMID: 32842072 DOI: 10.1097/rct.0000000000001050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Incomplete partition III (IP-III), characterized by congenital mixed or sensorineural hearing loss, is a rare genetic disease transmitted through X-linked mode of inheritance. Inner ear findings of IP-III have been well described and allow an immediate diagnosis to be made. Recently, an association between IP-III and distinct hypothalamic malformations has been reported in some of the patients with IP-III. The purpose of this study was to investigate the morphologic abnormalities of the hypothalamus in IP-III. MATERIALS AND METHODS Magnetic resonance imaging studies of 8 subjects, including 1 set of brothers, who were diagnosed with IP-III based on their clinical and inner ear imaging findings, were analyzed. RESULTS Of the 8 subjects, 7 demonstrated some degree of morphologic abnormality of the hypothalamus. Of these, 2 showed asymmetrical thickening, 1 showed symmetrical thickening, and 4 showed mass-like enlargement of the hypothalamus. Six of 7 subjects with hypothalamic abnormalities showed asymmetry in caudal extension of the abnormalities, which was more discernible on coronal oblique T2-weighted images. Clinically, none of the subjects had endocrinologic or neurologic symptoms. CONCLUSIONS This retrospective analysis presents further magnetic resonance imaging evidence on the association between the rare IP-III malformations and the presence of hypothalamic morphologic abnormalities.
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A novel POU domain class 3 transcription factor 4 mutation causes X-linked non-syndromic hearing loss in a Chinese family. Chin Med J (Engl) 2020; 132:2251-2253. [PMID: 31490266 PMCID: PMC6797136 DOI: 10.1097/cm9.0000000000000425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Aristidou C, Theodosiou A, Bak M, Mehrjouy MM, Constantinou E, Alexandrou A, Papaevripidou I, Christophidou-Anastasiadou V, Skordis N, Kitsiou-Tzeli S, Tommerup N, Sismani C. Position effect, cryptic complexity, and direct gene disruption as disease mechanisms in de novo apparently balanced translocation cases. PLoS One 2018; 13:e0205298. [PMID: 30289920 PMCID: PMC6173455 DOI: 10.1371/journal.pone.0205298] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 09/21/2018] [Indexed: 12/03/2022] Open
Abstract
The majority of apparently balanced translocation (ABT) carriers are phenotypically normal. However, several mechanisms were proposed to underlie phenotypes in affected ABT cases. In the current study, whole-genome mate-pair sequencing (WG-MPS) followed by Sanger sequencing was applied to further characterize de novo ABTs in three affected individuals. WG-MPS precisely mapped all ABT breakpoints and revealed three possible underlying molecular mechanisms. Firstly, in a t(X;1) carrier with hearing loss, a highly skewed X-inactivation pattern was observed and the der(X) breakpoint mapped ~87kb upstream an X-linked deafness gene namely POU3F4, thus suggesting an underlying long-range position effect mechanism. Secondly, cryptic complexity and a chromothripsis rearrangement was identified in a t(6;7;8;12) carrier with intellectual disability. Two translocations and a heterozygous deletion disrupted SOX5; a dominant nervous system development gene previously reported in similar patients. Finally, a direct gene disruption mechanism was proposed in a t(4;9) carrier with dysmorphic facial features and speech delay. In this case, the der(9) breakpoint directly disrupted NFIB, a gene involved in lung maturation and development of the pons with important functions in main speech processes. To conclude, in contrast to familial ABT cases with identical rearrangements and discordant phenotypes, where translocations are considered coincidental, translocations seem to be associated with phenotype presentation in affected de novo ABT cases. In addition, this study highlights the importance of investigating both coding and non-coding regions to decipher the underlying pathogenic mechanisms in these patients, and supports the potential introduction of low coverage WG-MPS in the clinical investigation of de novo ABTs.
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Affiliation(s)
- Constantia Aristidou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
- The Cyprus School of Molecular Medicine, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Athina Theodosiou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Mads Bak
- Wilhelm Johannsen Centre for Functional Genome Research, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen N., Denmark
| | - Mana M. Mehrjouy
- Wilhelm Johannsen Centre for Functional Genome Research, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen N., Denmark
| | - Efthymia Constantinou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Angelos Alexandrou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Ioannis Papaevripidou
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | | | - Nicos Skordis
- Division of Pediatric Endocrinology, Paedi Center for Specialized Pediatrics, Nicosia, Cyprus
- St George’s University of London Medical School at the University of Nicosia, Nicosia, Cyprus
| | - Sophia Kitsiou-Tzeli
- Department of Medical Genetics, Medical School, University of Athens, Athens, Greece
| | - Niels Tommerup
- Wilhelm Johannsen Centre for Functional Genome Research, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen N., Denmark
| | - Carolina Sismani
- Department of Cytogenetics and Genomics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
- The Cyprus School of Molecular Medicine, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
- * E-mail:
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A novel mutation in the SMPX gene associated with X-linked nonsyndromic sensorineural hearing loss in a Chinese family. J Hum Genet 2018; 63:723-730. [PMID: 29559740 DOI: 10.1038/s10038-018-0443-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Revised: 02/05/2018] [Accepted: 03/01/2018] [Indexed: 12/19/2022]
Abstract
X-linked inheritance is very rare and is estimated to account for only 1-5% of all nonsyndromic hearing loss cases. We found a multiplex family from China segregating with X-linked nonsyndromic hearing loss. After exclusive analysis of 10 common variations of three hearing loss-related genes, GJB2, mtDNA12srRNA and SLC26A4, a novel truncated variant of SMPX, c.87dupA (p.Gly30Argfs*12) (NCBI ClinVar Submission ID: SUB3136126), was identified by whole-exome sequencing. This variant was co-segregated with hearing loss in the entire family and was absent in 576 unrelated ethnically and geographically matched controls. We also detected a single nucleotide variation in two male controls with normal hearing, SMPX c.55A>G (p.Asn19Asp), which has been annotated as a rare variant in the Single Nucleotide Polymorphism (dbSNP) (rs759552778) and Exome Aggregation Consortium (ExAC) databases. This study has enriched the mutation spectrum of the SMPX gene.
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