1
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Phenotype-genotype correlation in patients with typical and atypical branchio-oto-renal syndrome. Sci Rep 2022; 12:969. [PMID: 35046468 PMCID: PMC8770796 DOI: 10.1038/s41598-022-04885-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 12/29/2021] [Indexed: 12/31/2022] Open
Abstract
Some patients have an atypical form of branchio-oto-renal (BOR) syndrome, which does not satisfy the diagnostic criteria, despite carrying a pathogenic variant (P variant) or a likely pathogenic variant (LP variant) of a causative gene. P/LP variants phenotypic indices have yet to be determined in patients with typical and atypical BOR syndrome. We hypothesized that determining phenotypic and genetic differences between patients with typical and atypical BOR syndrome could inform such indices. Subjects were selected from among patients who underwent genetic testing to identify the cause of hearing loss. Patients were considered atypical when they had two major BOR diagnostic criteria, or two major criteria and one minor criterion; 22 typical and 16 atypical patients from 35 families were included. Genetic analysis of EYA1, SIX1, and SIX5 was conducted by direct sequencing and multiplex ligation-dependent probe amplification. EYA1 P/LP variants were detected in 25% and 86% of atypical and typical patients, respectively. Four EYA1 P/LP variants were novel. Branchial anomaly, inner ear anomaly, and mixed hearing loss were correlated with P/LP variants. Development of refined diagnostic criteria and phenotypic indices for atypical BOR syndrome will assist in effective detection of patients with P/LP variants among those with suspected BOR syndrome.
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2
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Identification and Characterization of a Cryptic Genomic Deletion-Insertion in EYA1 Associated with Branchio-Otic Syndrome. Neural Plast 2021; 2021:5524381. [PMID: 33880118 PMCID: PMC8046558 DOI: 10.1155/2021/5524381] [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] [Received: 02/23/2021] [Accepted: 03/19/2021] [Indexed: 11/17/2022] Open
Abstract
Branchio-oto-renal spectrum disorder (BORSD) is characterized by hearing loss accompanied by ear malformations, branchial cysts, and fistulae, with (branchio-oto-renal syndrome (BORS)) or without renal abnormalities (BOS (branchio-otic syndrome)). As the most common causative gene for BORSD, dominant mutations in EYA1 are responsible for approximately 40% of the cases. In a sporadic deaf patient diagnosed as BOS, we identified an apparent heterozygous genomic deletion spanning the first four coding exons and one 5′ noncoding exon of EYA1 by targeted next-generation sequencing of 406 known deafness genes. Real-time PCR at multiple regions of EYA1 confirmed the existence of this genomic deletion and extended its 5′ boundary beyond the 5′-UTR. Whole genome sequencing subsequently located the 5′ and 3′ breakpoints to 19268 bp upstream to the ATG initiation codon and 3180 bp downstream to exon 5. PCR amplification across the breakpoints in both the patient and his parents showed that the genomic alteration occurred de novo. Sanger sequencing of this PCR product revealed that it is in fact a GRCh38/hg38:chr8:g.71318554_71374171delinsTGCC genomic deletion-insertion. Our results showed that the genomic variant is responsible for the hearing loss associated with BOS and provided an example for deciphering such cryptic genomic alterations following pipelines of comprehensive exome/genome sequencing and designed verification.
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Chen A, Song J, Acke FRE, Mei L, Cai X, Feng Y, He C. Otological manifestations in branchiootorenal spectrum disorder: A systematic review and meta-analysis. Clin Genet 2021; 100:3-13. [PMID: 33624842 DOI: 10.1111/cge.13949] [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: 12/13/2020] [Revised: 02/09/2021] [Accepted: 02/20/2021] [Indexed: 11/30/2022]
Abstract
Branchiootorenal spectrum disorder (BORSD) is a group of rare autosomal dominant entities characterized by branchiogenic malformations, hearing loss (HL) and renal anomalies. It comprises branchiootorenal syndrome and branchiootic syndrome, distinguished by the presence or absence of renal abnormalities. Pathogenic variants have been discovered in the following genes: EYA1, SIX5, SIX1 and SALL1. As the otological phenotype in BORSD is inconsistently reported, we performed a systematic review to provide an up-to-date overview, correlated with the genotype. Forty publications were included, describing 295 individual patients. HL was diagnosed in 95%, usually bilateral and mixed-type, and differed among the different genes involved. Mixed moderate-to-severe HL was the predominant finding in patients with EYA1 involvement, regardless of the presence of renal abnormalities. The sensorineural HL of profound severity was more prevalent in patients with SIX1 mutations. No significant differences among different mutation types or location within the genes could be observed. Structural otological manifestations, ranging from periauricular to inner ear anomalies, were common in both genes. Especially periauricular anomalies were more common and more severe in EYA1. In summary, otological differences among the different genes involved in BORSD are observed, so the molecular analysis is strongly advised.
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Affiliation(s)
- Anhai Chen
- Department of Otorhinolaryngology, Xiangya Hospital Central South University, Changsha, Hunan, China.,Key Laboratory of Otolaryngology Major Disease Research of Hunan Province, Changsha, Hunan, China.,National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Jian Song
- Department of Otorhinolaryngology, Xiangya Hospital Central South University, Changsha, Hunan, China.,Key Laboratory of Otolaryngology Major Disease Research of Hunan Province, Changsha, Hunan, China.,National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Frederic R E Acke
- Department of Otorhinolaryngology, Ghent University/Ghent University Hospital, Ghent, Belgium
| | - Lingyun Mei
- Department of Otorhinolaryngology, Xiangya Hospital Central South University, Changsha, Hunan, China.,Key Laboratory of Otolaryngology Major Disease Research of Hunan Province, Changsha, Hunan, China.,National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xinzhang Cai
- Department of Otorhinolaryngology, Xiangya Hospital Central South University, Changsha, Hunan, China.,Key Laboratory of Otolaryngology Major Disease Research of Hunan Province, Changsha, Hunan, China.,National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yong Feng
- Department of Otorhinolaryngology, Xiangya Hospital Central South University, Changsha, Hunan, China.,Key Laboratory of Otolaryngology Major Disease Research of Hunan Province, Changsha, Hunan, China.,Department of Otorhinolaryngology, Changsha Central Hospital, University of South China, Changsha, Hunan, China
| | - Chufeng He
- Department of Otorhinolaryngology, Xiangya Hospital Central South University, Changsha, Hunan, China.,Key Laboratory of Otolaryngology Major Disease Research of Hunan Province, Changsha, Hunan, China.,National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, Hunan, China
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4
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Gendron C, Schwentker A, van Aalst JA. Genetic Advances in the Understanding of Microtia. J Pediatr Genet 2016; 5:189-197. [PMID: 27895971 DOI: 10.1055/s-0036-1592422] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 09/30/2016] [Indexed: 10/20/2022]
Abstract
Microtia is a genetic condition affecting the external ears and presents clinically along a wide spectrum: minimally affected ears are small with minor shape abnormalities; extremely affected ears lack all identifiable structures, with the most extreme being absence of the entire external ear. Multiple genetic causes have been linked to microtia in both animal models and humans, which are improving our understanding of the condition and may lead to the identification of a unified cause for the condition. Microtia is also a prominent feature of several genetic syndromes, the study of which has provided further insight into the possible causes and genetic mechanisms of the condition. This article reviews our current understanding of microtia including epidemiological characteristics, classification systems, environmental and genetic causative factors leading to microtia. Despite our increased understanding of the genetics of microtia, we do not have a means of preventing the condition and still rely on complex staged, surgical correction.
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Affiliation(s)
- Craig Gendron
- Craniofacial and Pediatric Plastic Surgery, Saskatoon Health Region of Saskatchewan, Saskatoon, Canada
| | - Ann Schwentker
- Division of Plastic Surgery, University of Cincinnati, Cincinnati, Ohio, United States
| | - John A van Aalst
- Division of Plastic Surgery, University of Cincinnati, Cincinnati, Ohio, United States
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5
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Gendrel AV, Marion-Poll L, Katoh K, Heard E. Random monoallelic expression of genes on autosomes: Parallels with X-chromosome inactivation. Semin Cell Dev Biol 2016; 56:100-110. [PMID: 27101886 DOI: 10.1016/j.semcdb.2016.04.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 04/08/2016] [Accepted: 04/15/2016] [Indexed: 01/04/2023]
Abstract
Genes are generally expressed from their two alleles, except in some particular cases such as random inactivation of one of the two X chromosomes in female mammals or imprinted genes which are expressed only from the maternal or the paternal allele. A lesser-known phenomenon is random monoallelic expression (RME) of autosomal genes, where genes can be stably expressed in a monoallelic manner, from either one of the parental alleles. Studies on autosomal RME face several challenges. First, RME that is based on epigenetic mechanisms has to be distinguished from biased expression of one allele caused by a DNA sequence polymorphism in a regulatory element. Second, RME should not be confused with transient monoallelic expression often observed in single cell analyses, and that often corresponds to dynamic bursting of expression. Thanks to analyses on clonal cell populations, the existence of RME in cultured cells is now well established. Future studies of RME in vivo will have to overcome tissue heterogeneity and certain technical limitations. Here, we discuss current knowledge on autosomal RME, as well as possible mechanisms controlling these expression patterns and potential implications for development and disease, drawing parallels with what is known for X-chromosome inactivation, a paradigm of random monoallelic expression.
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Affiliation(s)
- Anne-Valerie Gendrel
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Mammalian Developmental Epigenetics group, F-75005 Paris, France; Sorbonne Universités, UPMC Univ Paris 6, F-75005 Paris, France.
| | - Lucile Marion-Poll
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Mammalian Developmental Epigenetics group, F-75005 Paris, France; Sorbonne Universités, UPMC Univ Paris 6, F-75005 Paris, France
| | - Kimiko Katoh
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Mammalian Developmental Epigenetics group, F-75005 Paris, France; Sorbonne Universités, UPMC Univ Paris 6, F-75005 Paris, France
| | - Edith Heard
- Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Mammalian Developmental Epigenetics group, F-75005 Paris, France; Sorbonne Universités, UPMC Univ Paris 6, F-75005 Paris, France.
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6
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Abstract
Cranial sensory placodes derive from discrete patches of the head ectoderm and give rise to numerous sensory structures. During gastrulation, a specialized "neural border zone" forms around the neural plate in response to interactions between the neural and nonneural ectoderm and signals from adjacent mesodermal and/or endodermal tissues. This zone subsequently gives rise to two distinct precursor populations of the peripheral nervous system: the neural crest and the preplacodal ectoderm (PPE). The PPE is a common field from which all cranial sensory placodes arise (adenohypophyseal, olfactory, lens, trigeminal, epibranchial, otic). Members of the Six family of transcription factors are major regulators of PPE specification, in partnership with cofactor proteins such as Eya. Six gene activity also maintains tissue boundaries between the PPE, neural crest, and epidermis by repressing genes that specify the fates of those adjacent ectodermally derived domains. As the embryo acquires anterior-posterior identity, the PPE becomes transcriptionally regionalized, and it subsequently becomes subdivided into specific placodes with distinct developmental fates in response to signaling from adjacent tissues. Each placode is characterized by a unique transcriptional program that leads to the differentiation of highly specialized cells, such as neurosecretory cells, sensory receptor cells, chemosensory neurons, peripheral glia, and supporting cells. In this review, we summarize the transcriptional and signaling factors that regulate key steps of placode development, influence subsequent sensory neuron specification, and discuss what is known about mutations in some of the essential PPE genes that underlie human congenital syndromes.
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Affiliation(s)
- Sally A Moody
- Department of Anatomy and Regenerative Biology, The George Washington University, School of Medicine and Health Sciences, Washington, DC, USA; George Washington University Institute for Neuroscience, Washington, DC, USA.
| | - Anthony-Samuel LaMantia
- George Washington University Institute for Neuroscience, Washington, DC, USA; Department of Pharmacology and Physiology, The George Washington University, School of Medicine and Health Sciences, Washington, DC, USA
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7
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Yan B, Neilson KM, Ranganathan R, Maynard T, Streit A, Moody SA. Microarray identification of novel genes downstream of Six1, a critical factor in cranial placode, somite, and kidney development. Dev Dyn 2014; 244:181-210. [PMID: 25403746 DOI: 10.1002/dvdy.24229] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 11/03/2014] [Accepted: 11/12/2014] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Six1 plays an important role in the development of several vertebrate organs, including cranial sensory placodes, somites, and kidney. Although Six1 mutations cause one form of branchio-otic syndrome (BOS), the responsible gene in many patients has not been identified; genes that act downstream of Six1 are potential BOS candidates. RESULTS We sought to identify novel genes expressed during placode, somite and kidney development by comparing gene expression between control and Six1-expressing ectodermal explants. The expression patterns of 19 of the significantly up-regulated and 11 of the significantly down-regulated genes were assayed from cleavage to larval stages. A total of 28/30 genes are expressed in the otocyst, a structure that is functionally disrupted in BOS, and 26/30 genes are expressed in the nephric mesoderm, a structure that is functionally disrupted in the related branchio-otic-renal (BOR) syndrome. We also identified the chick homologues of five genes and show that they have conserved expression patterns. CONCLUSIONS Of the 30 genes selected for expression analyses, all are expressed at many of the developmental times and appropriate tissues to be regulated by Six1. Many have the potential to play a role in the disruption of hearing and kidney function seen in BOS/BOR patients.
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Affiliation(s)
- Bo Yan
- Department of Anatomy and Regenerative Biology, The George Washington University, School of Medicine and Health Sciences, Washington, DC
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8
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Identification of a novel nonsynonymous mutation of EYA1 disrupting splice site in a Korean patient with BOR syndrome. Mol Biol Rep 2014; 41:4321-7. [DOI: 10.1007/s11033-014-3303-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 02/14/2014] [Indexed: 10/25/2022]
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9
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Saint-Jeannet JP, Moody SA. Establishing the pre-placodal region and breaking it into placodes with distinct identities. Dev Biol 2014; 389:13-27. [PMID: 24576539 DOI: 10.1016/j.ydbio.2014.02.011] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 02/13/2014] [Accepted: 02/14/2014] [Indexed: 11/17/2022]
Abstract
Specialized sensory organs in the vertebrate head originate from thickenings in the embryonic ectoderm called cranial sensory placodes. These placodes, as well as the neural crest, arise from a zone of ectoderm that borders the neural plate. This zone separates into a precursor field for the neural crest that lies adjacent to the neural plate, and a precursor field for the placodes, called the pre-placodal region (PPR), that lies lateral to the neural crest. The neural crest domain and the PPR are established in response to signaling events mediated by BMPs, FGFs and Wnts, which differentially activate transcription factors in these territories. In the PPR, members of the Six and Eya families, act in part to repress neural crest specific transcription factors, thus solidifying a placode developmental program. Subsequently, in response to environmental cues the PPR is further subdivided into placodal territories with distinct characteristics, each expressing a specific repertoire of transcription factors that provide the necessary information for their progression to mature sensory organs. In this review we summarize recent advances in the characterization of the signaling molecules and transcriptional effectors that regulate PPR specification and its subdivision into placodal domains with distinct identities.
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Affiliation(s)
- Jean-Pierre Saint-Jeannet
- Department of Basic Science and Craniofacial Biology, New York University, College of Dentistry, 345 East 24th Street, New York City, NY 10010, USA.
| | - Sally A Moody
- Department of Anatomy and Regenerative Biology, The George Washington University, School of Medicine and Health Sciences, 2300 I (eye) Street, NW, Washington, DC 20037, USA.
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10
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Musharraf A, Kruspe D, Tomasch J, Besenbeck B, Englert C, Landgraf K. BOR-syndrome-associated Eya1 mutations lead to enhanced proteasomal degradation of Eya1 protein. PLoS One 2014; 9:e87407. [PMID: 24489909 PMCID: PMC3906160 DOI: 10.1371/journal.pone.0087407] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 12/27/2013] [Indexed: 11/18/2022] Open
Abstract
Mutations in the human EYA1 gene have been associated with several human diseases including branchio-oto (BO) and branchio-oto-renal (BOR) syndrome, as well as congenital cataracts and ocular anterior segment anomalies. BOR patients suffer from severe malformations of the ears, branchial arches and kidneys. The phenotype of Eya1-heterozygous mice resembles the symptoms of human patients suffering from BOR syndrome. The Eya1 gene encodes a multifunctional protein that acts as a protein tyrosine phosphatase and a transcriptional coactivator. It has been shown that Eya1 interacts with Six transcription factors, which are also required for nuclear translocation of the Eya1 protein. We investigated the effects of seven disease-causing Eya1 missense mutations on Eya1 protein function, in particular cellular localization, ability to interact with Six proteins, and protein stability. We show here that the BOR-associated Eya1 missense mutations S454P, L472R, and L550P lead to enhanced proteasomal degradation of the Eya1 protein in mammalian cells. Moreover, Six proteins lead to a significant stabilization of Eya1, which is caused by Six-mediated protection from proteasomal degradation. In case of the mutant L550P, loss of interaction with Six proteins leads to rapid protein degradation. Our observations suggest that protein destabilization constitutes a novel disease causing mechanism for Eya1.
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Affiliation(s)
- Amna Musharraf
- Leibniz Institute for Age Research - Fritz Lipmann Institute e. V. (FLI), Jena, Germany
| | - Dagmar Kruspe
- Leibniz Institute for Age Research - Fritz Lipmann Institute e. V. (FLI), Jena, Germany
| | - Jürgen Tomasch
- Leibniz Institute for Age Research - Fritz Lipmann Institute e. V. (FLI), Jena, Germany
| | - Birgit Besenbeck
- Leibniz Institute for Age Research - Fritz Lipmann Institute e. V. (FLI), Jena, Germany
| | - Christoph Englert
- Leibniz Institute for Age Research - Fritz Lipmann Institute e. V. (FLI), Jena, Germany
| | - Kathrin Landgraf
- Leibniz Institute for Age Research - Fritz Lipmann Institute e. V. (FLI), Jena, Germany
- * E-mail:
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11
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Gigante M, d'Altilia M, Montemurno E, Diella S, Bruno F, Netti GS, Ranieri E, Stallone G, Infante B, Grandaliano G, Gesualdo L. Branchio-Oto-Renal Syndrome (BOR) associated with focal glomerulosclerosis in a patient with a novel EYA1 splice site mutation. BMC Nephrol 2013; 14:60. [PMID: 23506628 PMCID: PMC3610161 DOI: 10.1186/1471-2369-14-60] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 03/13/2013] [Indexed: 12/22/2022] Open
Abstract
Background Branchio-oto-renal (BOR) syndrome is an autosomal dominant disorder characterized by branchial, ear, and renal anomalies. The most common gene mutated in BOR patients is EYA1, the human homolog of the Drosophila eyes absent gene, while mutations in SIX1 gene, the human homolog of sine oculis, encoding a DNA binding protein interacting with EYA1, have been reported less frequently. Recently, mutations in another SIX family member, SIX5, have been described in BOR patients, however, this association has not been confirmed by other groups. Case presentation In this study, we have clinically and genetically characterized a proband that displayed hearing loss, pre-auricular pits, branchial fistulae, hypoplasia of the left kidney, bilateral mild hydronephrosis, progressive proteinuria and focal glomerulosclerosis. Mutational analysis of EYA1 gene revealed a novel splice site mutation, c.1475 + 1G > C, that affects EYA1 splicing and produces an aberrant mRNA transcript, lacking exon 15, which is predicted to encode a truncated protein of 456 aa. Conclusion This report provided the functional description of a novel EYA1 splice site mutation and described for the first time a case of BOR syndrome associated with the atypical renal finding of focal glomerulosclerosis, highlighting the importance of molecular testing and detailed clinical evaluation to provide accurate diagnosis and appropriate genetic counselling.
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Affiliation(s)
- Maddalena Gigante
- Department of Medical and Surgical Sciences, University of Foggia, Foggia, Italy.
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12
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Luquetti DV, Heike CL, Hing AV, Cunningham ML, Cox TC. Microtia: epidemiology and genetics. Am J Med Genet A 2012; 158A:124-39. [PMID: 22106030 PMCID: PMC3482263 DOI: 10.1002/ajmg.a.34352] [Citation(s) in RCA: 246] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Accepted: 09/12/2011] [Indexed: 12/26/2022]
Abstract
Microtia is a congenital anomaly of the ear that ranges in severity from mild structural abnormalities to complete absence of the ear, and can occur as an isolated birth defect or as part of a spectrum of anomalies or a syndrome. Microtia is often associated with hearing loss and patients typically require treatment for hearing impairment and surgical ear reconstruction. The reported prevalence varies among regions, from 0.83 to 17.4 per 10,000 births, and the prevalence is considered to be higher in Hispanics, Asians, Native Americans, and Andeans. The etiology of microtia and the cause of this wide variability in prevalence are poorly understood. Strong evidence supports the role of environmental and genetic causes for microtia. Although some studies have identified candidate genetic variants for microtia, no causal genetic mutation has been confirmed. The application of novel strategies in developmental biology and genetics has facilitated elucidation of mechanisms controlling craniofacial development. In this paper we review current knowledge of the epidemiology and genetics of microtia, including potential candidate genes supported by evidence from human syndromes and animal models. We also discuss the possible etiopathogenesis in light of the hypotheses formulated to date: Neural crest cells disturbance, vascular disruption, and altitude.
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Affiliation(s)
- Daniela V Luquetti
- Division of Craniofacial Medicine, Department of Pediatrics, University of Washington, Seattle, Washington, USA.
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13
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Krug P, Morinière V, Marlin S, Koubi V, Gabriel HD, Colin E, Bonneau D, Salomon R, Antignac C, Heidet L. Mutation screening of the EYA1, SIX1, and SIX5 genes in a large cohort of patients harboring branchio-oto-renal syndrome calls into question the pathogenic role of SIX5 mutations. Hum Mutat 2011; 32:183-90. [PMID: 21280147 DOI: 10.1002/humu.21402] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Branchio-oto-renal (BOR) syndrome is an autosomal dominant disorder characterized by branchial, ear, and renal anomalies. Over 80 mutations in EYA1 have been reported in BOR. Mutations in SIX1, a DNA binding protein that associates with EYA1, have been reported less frequently. One group has recently described four missense mutations in SIX5 in five unrelated patients with BOR. Here, we report a screening of these three genes in a cohort of 140 patients from 124 families with BOR. We identified 36 EYA1 mutations in 42 unrelated patients, 2 mutations, and 1 change of unknown significance in SIX1 in 3 unrelated patients, but no mutation in SIX5. We did not find correlation between genotype and phenotype, and observed a high phenotypic variability between and within BOR families. We show the difficulty in establishing a molecular diagnosis strategy in BOR syndrome: the screening focusing on patients with typical BOR would detect a mutation rate of 76%, but would also miss mutations in 9% of patients with atypical BOR. We detected a deletion removing three EYA1 exons in a patient who was previously reported to carry the SIX5 Thr552Met mutation. This led us to reconsider the role of SIX5 in the development of BOR.
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Affiliation(s)
- Pauline Krug
- AP-HP, Service de Néphrologie Pédiatrique, Hôpital Necker-Enfants Malades, Paris, France
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14
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Neilson KM, Pignoni F, Yan B, Moody SA. Developmental expression patterns of candidate cofactors for vertebrate six family transcription factors. Dev Dyn 2010; 239:3446-66. [PMID: 21089078 PMCID: PMC3059517 DOI: 10.1002/dvdy.22484] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Six family transcription factors play important roles in craniofacial development. Their transcriptional activity can be modified by cofactor proteins. Two Six genes and one cofactor gene (Eya1) are involved in the human Branchio-otic (BO) and Branchio-otic-renal (BOR) syndromes. However, mutations in Six and Eya genes only account for approximately half of these patients. To discover potential new causative genes, we searched the Xenopus genome for orthologues of Drosophila cofactor proteins that interact with the fly Six-related factor, SO. We identified 33 Xenopus genes with high sequence identity to 20 of the 25 fly SO-interacting proteins. We provide the developmental expression patterns of the Xenopus orthologues for 11 of the fly genes, and demonstrate that all are expressed in developing craniofacial tissues with at least partial overlap with Six1/Six2. We speculate that these genes may function as Six-interacting partners with important roles in vertebrate craniofacial development and perhaps congenital syndromes.
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Affiliation(s)
- Karen M Neilson
- Department of Anatomy and Regenerative Biology, The George Washington University, School of Medicine and Health Sciences, Washington, DC 20037, USA.
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15
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EYA1 mutations associated with the branchio-oto-renal syndrome result in defective otic development in Xenopus laevis. Biol Cell 2010; 102:277-92. [PMID: 19951260 PMCID: PMC2825735 DOI: 10.1042/bc20090098] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Background information. The BOR (branchio-oto-renal) syndrome is a dominant disorder most commonly caused by mutations in the EYA1 (Eyes Absent 1) gene. Symptoms commonly include deafness and renal anomalies. Results. We have used the embryos of the frog Xenopus laevis as an animal model for early ear development to examine the effects of different EYA1 mutations. Four eya1 mRNAs encoding proteins correlated with congenital anomalies in human were injected into early stage embryos. We show that the expression of mutations associated with BOR, even in the presence of normal levels of endogenous eya1 mRNA, leads to morphologically abnormal ear development as measured by overall otic vesicle size, establishment of sensory tissue and otic innervation. The molecular consequences of mutant eya1 expression were assessed by QPCR (quantitative PCR) analysis and in situ hybridization. Embryos expressing mutant eya1 showed altered levels of multiple genes (six1, dach, neuroD, ngnr-1 and nt3) important for normal ear development. Conclusions. These studies lend support to the hypothesis that dominant-negative effects of EYA1 mutations may have a role in the pathogenesis of BOR.
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Kemperman MH, Koch SMP, Kumar S, Huygen PLM, Joosten FBM, Cremers CWRJ. Evidence of progression and fluctuation of hearing impairment in branchio-oto-renal syndrome. Int J Audiol 2009; 43:523-32. [PMID: 15726843 DOI: 10.1080/14992020400050067] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
We retrospectively analysed long-term serial audiometry data from patients with branchio-oto-renal (BOR) syndrome to show the features of progression and fluctuation in hearing impairment and relate the findings to age and magnetic resonance imaging (MRI) findings in the petrosal bones. Thirty-two clinically affected BOR patients from six Dutch families (A-F) were included. Audiograms were available in 24 cases, covering followup intervals of between 3 and 30 years, and suitable for individual statistical analysis in 16 cases: 14 cases also had MRI findings. Significant progression in hearing impairment was found in 10 cases, while findings of significant fluctuation were made in seven cases. These findings did not clearly correlate with MRI findings. Substantial fluctuation occurred only in cases followed at a relatively young age. Patients with an enlarged endolymphatic duct and/or sac showed significantly higher sensorineural hearing thresholds than those with either normal MRI findings or cochlear/labyrinthine hypoplasia with or without enlarged duct or sac. We conclude that progressive, fluctuant hearing loss occurred in some BOR patients; however, only young patients showed substantial threshold fluctuation. BOR patients with an enlarged endolymphatic duct and/or sac on MRI seemed to be predisposed to developing more severe hearing impairment.
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Affiliation(s)
- Mathyus H Kemperman
- Department of Otorhinolaryngology, University Medical Centre Nijmegen, Nijmegen, The Netherlands.
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17
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Musharraf A, Markschies N, Teichmann K, Pankratz S, Landgraf K, Englert C, Imhof D. Eyes Absent Proteins: Characterization of Substrate Specificity and Phosphatase Activity of Mutants Associated with Branchial, Otic and Renal Anomalies. Chembiochem 2008; 9:2285-94. [DOI: 10.1002/cbic.200800224] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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18
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Orten DJ, Fischer SM, Sorensen JL, Radhakrishna U, Cremers CW, Marres HA, Van Camp G, Welch KO, Smith RJ, Kimberling WJ. Branchio-oto-renal syndrome (BOR): novel mutations in theEYA1gene, and a review of the mutational genetics of BOR. Hum Mutat 2008; 29:537-44. [DOI: 10.1002/humu.20691] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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19
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Abstract
Branchio-oto-renal syndrome, a phenotype consisting of hearing loss, auricular malformations, branchial arch remnants, and renal anomalies is now recognized as one of the more common forms of autosomal dominant syndromic hearing impairment. Three loci known to be associated with the BOR phenotype have been identified and two genes that act in a regulatory network have been cloned, EYA1 and SIX1. EYA1 and SIX1 are homologous to genes involved in Drosophila eye development, eyes absent gene (eya), and sine oculis (so), respectively. EYA1, a transcriptional co-activator has a conserved, 271-amino acid, C-terminal known as the Eya Domain (ED). SIX1 has two highly conserved domains; a homeodomain (HD) and a specific Six-domain (SD) whose products function as transcription factors with specific DNA-binding activity that are crucial for protein-protein interaction. To determine the molecular basis for the organ defects that occur in BOR syndrome, many studies have focused on the effects of mutations to EYA and effects of mutations of the EYA-SIX regulatory system. However, over 60% of BOR syndrome patients do not have known mutations in EYA1 and relatively little is known about mutations to SIX1. Further evaluation of SIX1 and its related target genes may provide a better understanding of the pathophysiology of BOR syndrome and offer greater clues to the disease mechanisms.
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Affiliation(s)
- Amit Kochhar
- Molecular Otolaryngology Research Laboratories, University of Iowa, Iowa City, Iowa 52242, USA
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20
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Okada M, Fujimaru R, Morimoto N, Satomura K, Kaku Y, Tsuzuki K, Nozu K, Okuyama T, Iijima K. EYA1 and SIX1 gene mutations in Japanese patients with branchio-oto-renal (BOR) syndrome and related conditions. Pediatr Nephrol 2006; 21:475-81. [PMID: 16491411 DOI: 10.1007/s00467-006-0041-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2005] [Revised: 10/09/2005] [Accepted: 11/08/2005] [Indexed: 10/25/2022]
Abstract
We isolated genomic DNA from 15 patients with branchio-oto-renal (BOR) syndrome or BOR-related conditions. Seven patients had BOR syndrome (two familial and five sporadic), and eight had deafness and renal malformations without branchial fistula (BOR-related conditions). We analyzed all exons and exon-intron boundaries of EYA1 and SIX1 using the polymerase chain reaction (PCR) direct sequencing, and characterized their mutations. In some patients, analysis of mRNA by reverse transcription (RT)-PCR was performed to examine whether the mutation affects the mRNA splicing. We identified five novel disease-causing heterozygous EYA1 mutations in five patients with BOR syndrome (two familial and three sporadic, 5/7=71%), but EYA1 and SIX1 mutations were not detected in the other two patients with BOR syndrome or any of the patients with BOR-related conditions. The detected EYA1 mutations were two nonsense mutations, two splicing acceptor-site mutations, and a point mutation (G>T) of the first base of exon 10. Analysis of mRNA by RT-PCR direct sequencing revealed that the latter point mutation led to the skipping of exon 10. In conclusion, (1) EYA1 mutations are a major cause of BOR syndrome in Japanese, (2) EYA1 and SIX1 mutations were not a major cause of BOR-related conditions, (3) we demonstrated for the first time that the point mutation (G>T) of the first base of the exon in EYA1 gene induced exon skipping.
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Affiliation(s)
- Michiyo Okada
- Department of Clinical Genetics and Molecular Medicine, National Center for Child Health and Development, Tokyo, Japan
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21
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Brugmann SA, Moody SA. Induction and specification of the vertebrate ectodermal placodes: precursors of the cranial sensory organs. Biol Cell 2005; 97:303-19. [PMID: 15836430 DOI: 10.1042/bc20040515] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The sensory organs of the vertebrate head derive from two embryological structures, the neural crest and the ectodermal placodes. Although quite a lot is known about the secreted and transcription factors that regulate neural crest development, until recently little was known about the molecular pathways that regulate placode development. Herein we review recent findings on the induction and specification of the pre-placodal ectoderm, and the transcription factors that are involved in regulating placode fate and initial differentiation.
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Affiliation(s)
- Samantha A Brugmann
- Department of Anatomy and Cell Biology, Genetics Program, The George Washington University, Washington, DC, USA
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22
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Kim SH, Shin JH, Yeo CK, Chang SH, Park SY, Cho EH, Ki CS, Kim JW. Identification of a novel mutation in the EYA1 gene in a Korean family with branchio-oto-renal (BOR) syndrome. Int J Pediatr Otorhinolaryngol 2005; 69:1123-8. [PMID: 16005355 DOI: 10.1016/j.ijporl.2005.03.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2004] [Accepted: 03/01/2005] [Indexed: 11/28/2022]
Abstract
The branchio-oto-renal (BOR) syndrome is an autosomal dominant disorder characterized by the association of branchial cysts or fistulae, external ear malformation and/or preauricular pits, hearing loss, and renal anomalies. Mutations in the EYA1 gene on the chromosome band 8q13.3, the human homologue of the Drosophila eyes absent (eya) gene, have been identified to be the underlying genetic defects of the syndrome. We found a Korean family with BOR syndrome and identified a novel insertion mutation (c.1474_1475insC; R492PfsX40) in the EYA1 gene. To the best of our knowledge, this is the first report of genetically confirmed case of BOR syndrome in Korea.
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Affiliation(s)
- Sung Hee Kim
- Department of Otolaryngology, Daegu Fatima Hospital, Daegu, Republic of Korea
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23
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Chang EH, Menezes M, Meyer NC, Cucci RA, Vervoort VS, Schwartz CE, Smith RJH. Branchio-oto-renal syndrome: the mutation spectrum in EYA1 and its phenotypic consequences. Hum Mutat 2004; 23:582-9. [PMID: 15146463 DOI: 10.1002/humu.20048] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
EYA1 mutations cause branchio-oto-renal (BOR) syndrome. These mutations include single nucleotide transitions and transversions, small duplications and deletions, and complex genomic rearrangements. The last cannot be detected by coding sequence analysis of EYA1. We sought to refine the clinical diagnosis of BOR syndrome by analyzing phenotypic data from families segregating EYA1 disease-causing mutations. Based on genotype-phenotype analyses, we propose new criteria for the clinical diagnosis of BOR syndrome. We found that in approximately 40% of persons meeting our criteria, EYA1 mutations were identified. Of these mutations, 80% were coding sequence variants identified by SSCP, and 20% were complex genomic rearrangements identified by a semiquantitative PCR-based screen. We conclude that genetic testing of EYA1 should include analysis of the coding sequence and a screen for complex rearrangements.
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Affiliation(s)
- Eugene H Chang
- Molecular Otolaryngology Research Labs, University of Iowa, Iowa City, Iowa 52242, USA
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24
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Migliosi V, Flex E, Guida V, Martini A, Giarbini N, Markova T, Torrente I, Dallapiccola B. Letters to the Editor. Clin Genet 2004; 66:478-80. [PMID: 15479196 DOI: 10.1111/j.1399-0004.2004.00318.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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25
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Abstract
Congenital abnormalities of the kidney and urinary tract, CAKUT are common in humans, occurring at a frequency of approximately 1 in 500 fetal ultrasound examinations. CAKUT are major causes of chronic renal failure in infants and young children, but little is known about the molecular pathogenesis of these disorders. To date, several gene mutations have been identified as a cause of human CAKUT: these include PAX2, KAL, EYA1, AGTR2 and HNF-1beta. At present, there is only limited information regarding how mutations alter gene expression during development to cause some CAKUT. The most convincing information comes from the multiorgan malformation syndromes with specific gene mutations. However, these syndromes are relatively rare, and most CAKUT appear to occur in isolation. The goal of this review is to provide an overview of these genetic disorders for CAKUT. An understanding of the genetic aspects of human CAKUT will help to unravel the pathogenesis of these disorders and may facilitate the design of genetic screening tests for early diagnosis and appropriate genetic counseling. Moreover, a deeper insight into the relationship between abnormal genes and the pathogenesis of abnormalities of CAKUT will provide an etiological classification of CAKUT. In addition, the importance of developing a registry of patients with various forms of CAKUT is discussed. This information will allow us to combine molecular biology and classical epidemiologic methods, and to continue expanding our knowledge regarding CAKUT.
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Affiliation(s)
- Koichi Nakanishi
- Department of Pediatrics, Wakayama Medical University, Wakayama, Japan.
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26
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Abstract
Inner ear induction, like induction of other tissues examined in recent years, is likely to be comprised of several stages. The process begins during gastrulation when the ectoderm is competent to respond to induction. It appears that a signal from the endomesoderm underlying the otic area during gastrulation initiates induction complemented by a signal from presumptive neural tissue. By the neural plate stage, a region of ectoderm outside the neural plate is "biased" toward ear formation; this process may be part of a more general "placodal" bias shared by several sensory tissues. Induction continues during neurulation when a signal from neural tissue (possibly augmented by mesoderm underlying the otic area) results in ectoderm committed to otic vesicle formation at the time of neural tube closure. Studies on several gene families implicate them in the ear determination process. Fibroblast Growth Factor (FGF) family members are clearly involved in induction: FGFs are appropriately expressed for such a role, and have been shown to be essential for inner ear development. FGFs also have inductive activity, although it is not clear if they are sufficient for ear induction. Activation of transcription factors in the otic ectoderm, for example, by Pax gene family members, provides evidence for important changes in the responding ectoderm beginning during gastrulation and continuing through specification at the end of neurulation, although few functional tests have defined the role of these genes in determination. The challenge remains to merge embryologic data with gene function studies to develop a clear model for the molecular basis of inner ear induction.
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Affiliation(s)
- Selina Noramly
- Department of Biology, University of Virginia, Gilmer Hall, Charlottesville, Virginia 22904, USA
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27
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Vervoort VS, Smith RJH, O'Brien J, Schroer R, Abbott A, Stevenson RE, Schwartz CE. Genomic rearrangements of EYA1 account for a large fraction of families with BOR syndrome. Eur J Hum Genet 2002; 10:757-66. [PMID: 12404110 DOI: 10.1038/sj.ejhg.5200877] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2002] [Revised: 07/05/2002] [Accepted: 07/11/2002] [Indexed: 11/09/2022] Open
Abstract
Branchio-Oto-Renal (BOR) syndrome is transmitted as an autosomal dominant disorder, affects an estimated 2% of profoundly deaf children, and is caused by mutations in the human EYA1 gene. However, in up to half of the reported cases, EYA1 mutation screening is negative. This finding has been taken as evidence of genetic heterogeneity. Mutation screening of the coding region of EYA1 in a panel of families linked to chromosome 8 was conducted using SSCP and direct sequencing. Only one point mutation in five probands was detected. However, complex rearrangements, such as inversions or large deletions, were discovered in the other four patients using Southern blot analysis. These data suggest that more complex rearrangements may remain undetected in EYA1 since SSCP and sequencing were commonly used to detect mutations in this gene.
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Affiliation(s)
- Virginie S Vervoort
- Department of Genetics and Biochemistry, Clemson University, Clemson, SC 29654, USA
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28
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Fukuda S, Kuroda T, Chida E, Shimizu R, Usami S, Koda E, Abe S, Namba A, Kitamura K, Inuyama Y. A family affected by branchio-oto syndrome with EYA1 mutations. Auris Nasus Larynx 2001; 28 Suppl:S7-11. [PMID: 11683347 DOI: 10.1016/s0385-8146(01)00082-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Branchio-oto (BO) syndrome is complicated with congenital preauricular fistulae, branchial fistulae (cysts), and hearing loss (sensorineural, conductive or mixed). As well as branchio-oto-renal (BOR) syndrome. it is known to be an autosomal dominant hereditary disorder. Since mutations in the EYA1 gene have been identified in both BO and BOR syndromes, mutation screening of this gene has been drawing attention as a genetic test to diagnose BOR/BO syndromes. In this study, we genetically investigated the presence of EYA1 mutations in a BO syndrome family in which we observed congenital preauricular fistulae, branchial fistulae (cysts) and hearing loss in four generations. Whereas there was a variety of phenotype expressions in this family, all subjects tested had a nonsense mutation (R264X) in exon 8 of the EYA1 gene. The present report adds further examples to support the usefulness of molecular genetic testing for the diagnosis of patients with BO syndrome.
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Affiliation(s)
- S Fukuda
- Department of Otolaryngology, Hokkaido University School of Medicine, Sapporo, Japan.
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29
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Bellini C, Piaggio G, Massocco D, Perfumo F, Bertini I, Gusmano R, Serra G. Branchio-oto-renal syndrome: A report on nine family groups. Am J Kidney Dis 2001. [DOI: 10.1053/ajkd.2001.22074] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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30
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Kumar S, Deffenbacher K, Marres HA, Cremers CW, Kimberling WJ. Genomewide search and genetic localization of a second gene associated with autosomal dominant branchio-oto-renal syndrome: clinical and genetic implications. Am J Hum Genet 2000; 66:1715-20. [PMID: 10762556 PMCID: PMC1378029 DOI: 10.1086/302890] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/1999] [Accepted: 02/21/2000] [Indexed: 11/04/2022] Open
Abstract
Branchio-oto-renal (BOR) syndrome is characterized by ear malformations, cervical fistulas, hearing loss, and renal anomalies. It is an autosomal dominant disorder with variable clinical manifestations. The most common features of BOR syndrome are branchial, hearing, and renal anomalies. However, many affected subjects have been observed with branchial-cleft anomalies and hearing loss but without renal anomalies, a condition called "branchio-otic" (BO) syndrome. It is logical to question whether the BOR and BO syndromes are allelic or whether they represent distinct genetic entities. We identified a very large extended family whose members had branchial and hearing anomalies associated with commissural lip pits that segregated in an autosomal dominant fashion. Using a genomewide search strategy, we identified genetic linkage, with a maximum LOD score of 4.81 at recombination fraction 0, between the BO phenotype and polymorphic marker D1S2757 in the genetic region of chromosome 1q31. This is the first report of linkage for a second gene associated with BOR syndrome. The findings have important clinical implications and will provide insight into the genetic basis of BOR syndrome.
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Affiliation(s)
- S Kumar
- Department of Genetics, Center for Hereditary and Communication Disorders, Boys Town National Research Hospital, Omaha, NE 68131, USA.
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31
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Kumar S, Kimberling WJ, Marres HA, Cremers CW. Genetic heterogeneity associated with branchio-oto-renal syndrome. AMERICAN JOURNAL OF MEDICAL GENETICS 1999; 83:207-8. [PMID: 10096598 DOI: 10.1002/(sici)1096-8628(19990319)83:3<207::aid-ajmg12>3.0.co;2-a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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