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1.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 37(11): 1213-1216, 2020 Nov 10.
Artigo em Chinês | MEDLINE | ID: mdl-33179223

RESUMO

OBJECTIVE: To detect additional variants for newborn carriers of single heterozygous variants of the GJB2 or SLC26A4 gene by genechip analysis in Changsha area, and explore the variation spectrum of deafness-related genes in this region. METHODS: For 462 newborns carrying single heterozygous variants of the GJB2 or SLC26A4 gene, all exons of the genes were subjected to Sanger sequencing. The pathogenicity of the variants was analyzed by database and literature search. RESULTS: For 305 newborns carrying a heterozygous GJB2 variant, 143 (46.49%) were found to carry additional variants, including 29 (9.51%) with c.109G>A likely pathogenic variant, and 1 (6.48%) with c.551G>A pathogenic variant. Among 153 newborns carrying single heterozygous variant of the SLC26A4 gene, 2 (1.31%) were found with a c.281C>T variant, and 1 (0.65%) with a c.1547_1548ins pathogenic variant. Among 4 newborns simultaneously carrying GJB2 and SLC26A4 variants, two were found to carry c.109G>A and c.844T>C variants (clinical significance unknown), respectively. CONCLUSION: For newborns carrying single heterozygous variants of the GJB2 or SLC26A4 gene by genechip analysis, the detection rate for other variants is quite high. Sanger sequencing can significantly improve the detection rate of high-risk newborns and enrich the variant spectrum of deafness genes.


Assuntos
Conexinas/genética , Triagem de Portadores Genéticos , Transportadores de Sulfato/genética , Análise Mutacional de DNA , Surdez/diagnóstico , Surdez/genética , Heterozigoto , Humanos , Recém-Nascido , Mutação , Análise de Sequência com Séries de Oligonucleotídeos
2.
Artigo em Chinês | MEDLINE | ID: mdl-33040498

RESUMO

Objective:To explore the genetic cause of a Chinese autosomal dominant nonsyndromic hearing loss family and investigate the clinical features and molecular genetic characteristics of this family. Method:Detailed medical history and systematic audiology tests were carried out in the family members, and they were subjected to comprehensive genetic analyses using massively parallel sequencing, which targeted 139 known deafness genes and 6 mitochondrial DNA mutations associated with hearing loss. Result:This family's hearing loss was consistent with autosomal dominant nonsyndromic hearing loss. The affected family members appeared to have developed a high-frequency hearing loss with the onset of twenties. We identified a heterozygous missense mutation, c.418A>G/p. Thr140Ala in the CEACAM16 gene, segregating with the deafness in this family. Conclusion:In this study, we identified a new mutation of CEACAM16 gene, which was the second mutation identified in Chinese hearing loss population. It has enriched the mutation spectrum of this gene.


Assuntos
Artrogripose , Surdez , Moléculas de Adesão Celular , Surdez/genética , Humanos , Mutação , Linhagem
3.
Nucleic Acids Res ; 48(19): 11113-11129, 2020 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-33045734

RESUMO

In this report, we investigated the molecular mechanism underlying a deafness-associated m.7516delA mutation affecting the 5' end processing sites of mitochondrial tRNAAsp and tRNASer(UCN). An in vitro processing experiment demonstrated that m.7516delA mutation caused the aberrant 5' end processing of tRNASer(UCN) and tRNAAsp precursors, catalyzed by RNase P. Using cytoplasmic hybrids (cybrids) derived from one hearing-impaired Chinese family bearing the m.7516delA mutation and control, we demonstrated the asymmetrical effects of m.7516delA mutation on the processing of tRNAs in the heavy (H)-strand and light (L)-strand polycistronic transcripts. Specially, the m.7516delA mutation caused the decreased levels of tRNASer(UCN) and downstream five tRNAs, including tRNATyr from the L-strand transcripts and tRNAAsp from the H-strand transcripts. Strikingly, mutant cybrids exhibited the lower level of COX2 mRNA and accumulation of longer and uncleaved precursors of COX2 from the H-strand transcripts. Aberrant RNA metabolisms yielded variable reductions in the mitochondrial proteins, especially marked reductions in the levels of ND4, ND5, CO1, CO2 and CO3. The impairment of mitochondrial translation caused the proteostasis stress and respiratory deficiency, diminished ATP production and membrane potential, increased production of reactive oxygen species and promoted apoptosis. Our findings provide new insights into the pathophysiology of deafness arising from mitochondrial tRNA processing defects.


Assuntos
DNA Mitocondrial/genética , Surdez/genética , RNA Mensageiro/metabolismo , RNA de Transferência de Ácido Aspártico/metabolismo , RNA de Transferência de Serina/metabolismo , Apoptose , Linhagem Celular , Respiração Celular , Humanos , Potencial da Membrana Mitocondrial , Proteínas Mitocondriais/metabolismo , Mutação , Processamento Pós-Transcricional do RNA , Espécies Reativas de Oxigênio/metabolismo
4.
Yi Chuan ; 42(8): 713-724, 2020 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-32952108

RESUMO

G protein-coupled receptors (GPCRs), the largest family of membrane protein receptors, can be activated by a variety of ligands and participate in signaling transduction, and they are essential in the physiologic process in vivo. GPCR-associated sorting proteins (GASPs) play an important role in the post-endocytic sorting of GPCRs. They mediate the degradation or recycling pathway, and regulate cell signaling transduction and other biological processes. The functional defects of GASPs have been reported to be implicated in pathogenesis of some neurological diseases, tumors and deafness and so on. In this review, we summarize the GASPs' function, GPCR-GASP interactions, GPCR sorting pathway and GASP-related signaling pathways implicated in the transcriptional regulation. It could help to understand the potential linkage between GASPs' dysfunction and diseases, and provide a new approach and strategy for the treatment of GASP-related diseases.


Assuntos
Surdez , Neoplasias , Doenças do Sistema Nervoso , Receptores Acoplados a Proteínas-G , Surdez/genética , Humanos , Ligantes , Neoplasias/genética , Doenças do Sistema Nervoso/genética , Transporte Proteico/genética , Receptores Acoplados a Proteínas-G/genética , Receptores Acoplados a Proteínas-G/metabolismo , Transdução de Sinais/genética
5.
Gene ; 761: 144996, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32738421

RESUMO

Sensorineural deafness in mammals is most commonly caused by damage to inner ear sensory epithelia, or hair cells, and can be attributed to genetic and environmental causes. After undergoing trauma, many non-mammalian organisms, including reptiles, birds, and zebrafish, are capable of regenerating damaged hair cells. Mammals, however, are not capable of regenerating damaged inner ear sensory epithelia, so that hair cell damage is permanent and can lead to hearing loss. The field of epigenetics, which is the study of various phenotypic changes caused by modification of genetic expression rather than alteration of DNA sequence, has seen numerous developments in uncovering biological mechanisms of gene expression and creating various medical treatments. However, there is a lack of information on the precise contribution of epigenetic modifications in the auditory system, specifically regarding their correlation with development of inner ear (cochlea) and consequent hearing impairment. Current studies have suggested that epigenetic modifications influence differentiation, development, and protection of auditory hair cells in cochlea, and can lead to hair cell degeneration. The objective of this article is to review the existing literature and discuss the advancements made in understanding epigenetic modifications of inner ear sensory epithelial cells. The analysis of the emerging epigenetic mechanisms related to inner ear sensory epithelial cells development, differentiation, protection, and regeneration will pave the way to develop novel therapeutic strategies for hearing loss.


Assuntos
Células Ciliadas Auditivas/citologia , Células Ciliadas Auditivas/fisiologia , Perda Auditiva Neurossensorial/genética , Animais , Diferenciação Celular/genética , Surdez/genética , Orelha Interna/crescimento & desenvolvimento , Epigênese Genética , Células Ciliadas Auditivas Internas/citologia , Células Ciliadas Auditivas Internas/fisiologia , Perda Auditiva/genética , Humanos , Regeneração/genética
6.
PLoS One ; 15(7): e0233582, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32735620

RESUMO

The craniofacial developmental disorder Burn-McKeown Syndrome (BMKS) is caused by biallelic variants in the pre-messenger RNA splicing factor gene TXNL4A/DIB1. The majority of affected individuals with BMKS have a 34 base pair deletion in the promoter region of one allele of TXNL4A combined with a loss-of-function variant on the other allele, resulting in reduced TXNL4A expression. However, it is unclear how reduced expression of this ubiquitously expressed spliceosome protein results in craniofacial defects during development. Here we reprogrammed peripheral mononuclear blood cells from a BMKS patient and her unaffected mother into induced pluripotent stem cells (iPSCs) and differentiated the iPSCs into induced neural crest cells (iNCCs), the key cell type required for correct craniofacial development. BMKS patient-derived iPSCs proliferated more slowly than both mother- and unrelated control-derived iPSCs, and RNA-Seq analysis revealed significant differences in gene expression and alternative splicing. Patient iPSCs displayed defective differentiation into iNCCs compared to maternal and unrelated control iPSCs, in particular a delay in undergoing an epithelial-to-mesenchymal transition (EMT). RNA-Seq analysis of differentiated iNCCs revealed widespread gene expression changes and mis-splicing in genes relevant to craniofacial and embryonic development that highlight a dampened response to WNT signalling, the key pathway activated during iNCC differentiation. Furthermore, we identified the mis-splicing of TCF7L2 exon 4, a key gene in the WNT pathway, as a potential cause of the downregulated WNT response in patient cells. Additionally, mis-spliced genes shared common sequence properties such as length, branch point to 3' splice site (BPS-3'SS) distance and splice site strengths, suggesting that splicing of particular subsets of genes is particularly sensitive to changes in TXNL4A expression. Together, these data provide the first insight into how reduced TXNL4A expression in BMKS patients might compromise splicing and NCC function, resulting in defective craniofacial development in the embryo.


Assuntos
Processamento Alternativo , Atresia das Cóanas/patologia , Surdez/congênito , Regulação da Expressão Gênica no Desenvolvimento , Cardiopatias Congênitas/patologia , Células-Tronco Pluripotentes Induzidas/citologia , Modelos Biológicos , Ribonucleoproteína Nuclear Pequena U5/deficiência , Spliceossomos/fisiologia , Apoptose , Diferenciação Celular , Técnicas de Reprogramação Celular , Atresia das Cóanas/genética , Células Clonais , Surdez/genética , Surdez/patologia , Transição Epitelial-Mesenquimal , Éxons/genética , Face/embriologia , Facies , Feminino , Cabeça/embriologia , Cardiopatias Congênitas/genética , Humanos , Crista Neural/citologia , Regiões Promotoras Genéticas/genética , Sítios de Splice de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ribonucleoproteína Nuclear Pequena U5/genética , Deleção de Sequência , Proteína 2 Semelhante ao Fator 7 de Transcrição/genética , Via de Sinalização Wnt
7.
Artigo em Chinês | MEDLINE | ID: mdl-32842192

RESUMO

To study the clinical features and causes of congenital Usher hearing loss in one child. Clinical examination, audiological tests, visual acuity examination were conducted in the proband and its family members, and second-generation sequencing technology for deafness gene detection was employed. The proband exhibited profound sensorineural deafness(hearing threshold>90 dB nHL). There was no visual loss after follow-up. Other family members had no history of hearing loss. The gene test indicated that the proband had a frameshift mutation for the thymine(T) deletion at the 1527 site of the Usher1C gene. The mutation was a homozygous mutation, and was from the father and the mother, respectively, which caused the truncation of the encoded protein. Normal function, Usher syndrome or non-syndromic deafness DFNB18 can occur. This is the first case in China demonstrating congenital deafness due to homozygous mutation of Usher1C gene c. 1527delT. This study enriches the gene spectrum of deafness in China.


Assuntos
Surdez/genética , Perda Auditiva Neurossensorial/genética , Síndromes de Usher , Criança , China , Testes Genéticos , Humanos , Mutação , Linhagem
8.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 37(9): 958-961, 2020 Sep 10.
Artigo em Chinês | MEDLINE | ID: mdl-32820507

RESUMO

OBJECTIVE: To determine the carrier rate of deafness-related genetic variants among 53 873 newborns from Zhengzhou. METHODS: Heel blood samples of the newborns were collected with informed consent from the parents, and 15 loci of 4 genes related to congenital deafness were detected by microarray. RESULTS: In total 2770 newborns were found to carry deafness-related variants, with a carrier rate of 5.142%. 1325 newborns (2.459%) were found to carry heterozygous variants of the GJB2 gene, 1071 (1.988%) were found with SLC26A4 gene variants, 205 were found with GJB3 gene variants (0.381%), and 120 were found with 12S rRNA variants (0.223%). Five newborns have carried homozygous GJB2 variants, two have carried homozygous SLC26A4 variants, five have carried compound heterozygous GJB2 variants, and four have carried compound heterozygous SLC26A4 variants. 33 neonates have carried heterozygous variants of two genes at the same time. CONCLUSION: The carrier rate of deafness-related variants in Zhengzhou, in a declining order, is for GJB2, SLC26A4, GJB3 and 12S rRNA. The common variants included GJB2 235delC and SLC26A4 IVS7-2A>G, which are similar to other regions in China. To carry out genetic screening of neonatal deafness can help to identify congenital, delayed and drug-induced deafness, and initiate treatment and follow-up as early as possible.


Assuntos
Coloboma/genética , Conexinas , Heterozigoto , Diagnóstico Pré-Natal , Insuficiência Renal/genética , Refluxo Vesicoureteral/genética , China , Coloboma/diagnóstico , Conexinas/genética , Análise Mutacional de DNA , Surdez/genética , Feminino , Feto , Homozigoto , Humanos , Recém-Nascido , Mutação , Fenótipo , Gravidez , Insuficiência Renal/diagnóstico , Transportadores de Sulfato/genética , Refluxo Vesicoureteral/diagnóstico
9.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 37(9): 962-967, 2020 Sep 10.
Artigo em Chinês | MEDLINE | ID: mdl-32820508

RESUMO

OBJECTIVE: To determine the types and frequency of deafness-related variants among 7875 newborns from Dongying area of Shandong Province. METHODS: One hundred loci of 18 common deafness genes were subjected to semiconductor sequencing. Variant site, frequency and distribution of the variants were analyzed. RESULTS: In total 552 deafness gene variants were detected among the 7875 newborns, which yielded a detection rate of 7.01%. Among these, common variant sites for GJB2, SLC26A4 and GJB3 genes were c.235delC, IVS7-2A>G and c.538C>T, respectively. The variant frequencies of matrilinear inheritance deafness genes MT-CO1, MT-RNR1, MT-TL1 and MT-TS1 were 0.38%, 0.25%, 0.1% and 0.01%, respectively. Four newborns were diagnosed with deafness, among which one had unilateral hearing loss. Analysis of the proportions of neonatal deafness-related variants in five counties of Dongying showed that the highest variant rate for the SLC26A4 gene compared with GJB2 was in Lijin county (51.76% vs. 40%), while the lowest was in Hekou county (30.77% vs. 56.41%). CONCLUSION: The carrier rate of deafness-related variants in Dongying area is higher than other regions of China, which may be attributed to the increased types and variant sites covered by the semiconductor sequencing method compared with the chip method and time-of-flight mass spectrometry. Due to geographical and population aggregation factors, the proportion of deafness variants in the five counties of Dongying differed significantly. Above results may provide a guide for the prevention of congenital deafness in Dongying area.


Assuntos
Conexinas , Surdez , Triagem Neonatal , China , Conexinas/genética , Análise Mutacional de DNA , Surdez/diagnóstico , Surdez/genética , Humanos , Recém-Nascido , Mutação , RNA Ribossômico , Transportadores de Sulfato/genética
10.
PLoS Genet ; 16(8): e1008953, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32776944

RESUMO

Apoptosis of cochlear hair cells is a key step towards age-related hearing loss. Although numerous genes have been implicated in the genetic causes of late-onset, progressive hearing loss, few show direct links to the proapoptotic process. By genome-wide linkage analysis and whole exome sequencing, we identified a heterozygous p.L183V variant in THOC1 as the probable cause of the late-onset, progressive, non-syndromic hearing loss in a large family with autosomal dominant inheritance. Thoc1, a member of the conserved multisubunit THO/TREX ribonucleoprotein complex, is highly expressed in mouse and zebrafish hair cells. The thoc1 knockout (thoc1 mutant) zebrafish generated by gRNA-Cas9 system lacks the C-startle response, indicative of the hearing dysfunction. Both Thoc1 mutant and knockdown zebrafish have greatly reduced hair cell numbers, while the latter can be rescued by embryonic microinjection of human wild-type THOC1 mRNA but to significantly lesser degree by the c.547C>G mutant mRNA. The Thoc1 deficiency resulted in marked apoptosis in zebrafish hair cells. Consistently, transcriptome sequencing of the mutants showed significantly increased gene expression in the p53-associated signaling pathway. Depletion of p53 or applying the p53 inhibitor Pifithrin-α significantly rescued the hair cell loss in the Thoc1 knockdown zebrafish. Our results suggested that THOC1 deficiency lead to late-onset, progressive hearing loss through p53-mediated hair cell apoptosis. This is to our knowledge the first human disease associated with THOC1 mutations and may shed light on the molecular mechanism underlying the age-related hearing loss.


Assuntos
Proteínas de Ligação a DNA/genética , Surdez/genética , Células Ciliadas Auditivas Internas/metabolismo , Proteínas de Ligação a RNA/genética , Proteína Supressora de Tumor p53/genética , Animais , Apoptose/genética , Benzotiazóis/farmacologia , Proteína 9 Associada à CRISPR/genética , Proteínas de Ligação a DNA/deficiência , Surdez/patologia , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Técnicas de Inativação de Genes , Células Ciliadas Auditivas/metabolismo , Células Ciliadas Auditivas/patologia , Células Ciliadas Auditivas Internas/patologia , Humanos , Camundongos , Mutação , RNA Guia/genética , Transdução de Sinais/efeitos dos fármacos , Tolueno/análogos & derivados , Tolueno/farmacologia , Proteína Supressora de Tumor p53/antagonistas & inibidores , Sequenciamento Completo do Exoma , Peixe-Zebra/genética
11.
Hum Genet ; 139(12): 1565-1574, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32562050

RESUMO

COCH is the most abundantly expressed gene in the cochlea. Unsurprisingly, mutations in COCH underly hearing loss in mice and humans. Two forms of hearing loss are linked to mutations in COCH, the well-established autosomal dominant nonsyndromic hearing loss, with or without vestibular dysfunction (DFNA9) via a gain-of-function/dominant-negative mechanism, and more recently autosomal recessive nonsyndromic hearing loss (DFNB110) via nonsense variants. Using a combination of targeted gene panels, exome sequencing, and functional studies, we identified four novel pathogenic variants (two nonsense variants, one missense, and one inframe deletion) in COCH as the cause of autosomal recessive hearing loss in a multi-ethnic cohort. To investigate whether the non-truncating variants exert their effect via a loss-of-function mechanism, we used minigene splicing assays. Our data showed both the missense and inframe deletion variants altered RNA splicing by creating an exon splicing silencer and abolishing an exon splicing enhancer, respectively. Both variants create frameshifts and are predicted to result in a null allele. This study confirms the involvement of loss-of-function mutations in COCH in autosomal recessive nonsyndromic hearing loss, expands the mutational landscape of DFNB110 to include coding variants that alter RNA splicing, and highlights the need to investigate the effect of coding variants on RNA splicing.


Assuntos
Surdez/genética , Proteínas da Matriz Extracelular/genética , Genes Recessivos/genética , Mutação com Perda de Função/genética , Adolescente , Adulto , Criança , Pré-Escolar , Cóclea/metabolismo , Cóclea/patologia , Códon sem Sentido/genética , Surdez/patologia , Éxons/genética , Feminino , Mutação da Fase de Leitura/genética , Humanos , Masculino , Linhagem
12.
PLoS One ; 15(5): e0232900, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32413090

RESUMO

Congenital deafness in the domestic dog is usually related to the presence of white pigmentation, which is controlled primarily by the piebald locus on chromosome 20 and also by merle on chromosome 10. Pigment-associated deafness is also seen in other species, including cats, mice, sheep, alpacas, horses, cows, pigs, and humans, but the genetic factors determining why some piebald or merle dogs develop deafness while others do not have yet to be determined. Here we perform a genome-wide association study (GWAS) to identify regions of the canine genome significantly associated with deafness in three dog breeds carrying piebald: Dalmatian, Australian cattle dog, and English setter. We include bilaterally deaf, unilaterally deaf, and matched control dogs from the same litter, phenotyped using the brainstem auditory evoked response (BAER) hearing test. Principal component analysis showed that we have different distributions of cases and controls in genetically distinct Dalmatian populations, therefore GWAS was performed separately for North American and UK samples. We identified one genome-wide significant association and 14 suggestive (chromosome-wide) associations using the GWAS design of bilaterally deaf vs. control Australian cattle dogs. However, these associations were not located on the same chromosome as the piebald locus, indicating the complexity of the genetics underlying this disease in the domestic dog. Because of this apparent complex genetic architecture, larger sample sizes may be needed to detect the genetic loci modulating risk in piebald dogs.


Assuntos
Surdez/veterinária , Doenças do Cão/genética , Animais , Estudos de Casos e Controles , Surdez/congênito , Surdez/genética , Cães , Potenciais Evocados Auditivos , Loci Gênicos , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Testes Auditivos , Polimorfismo de Nucleotídeo Único , Seleção Artificial , Pigmentação da Pele/genética
13.
Ann Endocrinol (Paris) ; 81(2-3): 68-77, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32409007

RESUMO

OBJECTIVE: While the most frequent mutation responsible for mitochondrial diabetes is the point mutation m.3243 A>G of mitochondrial DNA (mtDNA), few data are available about the role of rare mtDNA mutations in the pathophysiology of diabetes. The main objective of our study was to describe the phenotypic characteristics of patients suffering from diabetes linked to rare mtDNA mutations. RESEARCH DESIGN AND METHODS: We performed a post-hoc analysis of a prospective multicenter cohort of 743 patients with mitochondrial disorder (previously published by the French Network of Mitochondrial Diseases), associated to a literature review of the PubMed database from 1992 to May 2016. We extracted all reported patients with diabetes and identified rare mtDNA mutations and described their clinical and metabolic phenotypes. RESULTS: The 50 identified patients (10 from the princeps study; 40 from the review of the literature) showed a heterogeneous metabolic phenotype in terms of age, symptoms prior to diagnosis, treatments, and associated clinical and biological signs. However, neurological symptoms were more frequent in case of rare mtDNA mutations compared to the classical m.3243 A>G mutation (P=0.024). In contrast, deafness (65% vs. 95%, P=3.7E-5), macular pattern dystrophy (20% vs. 86%, P=1.6E-10) and nephropathy (8% vs. 28%, P=0.018) were significantly less frequent than in case of the classical m.3243 A>G mutation. CONCLUSION: Although no specific metabolic phenotype could be identified suggesting or eliminating implication of rare mtDNA mutations in diabetes, clinical phenotypes featured more frequent neurological signs.


Assuntos
DNA Mitocondrial/genética , Diabetes Mellitus/genética , Doenças Mitocondriais/genética , Mutação , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Estudos de Coortes , Análise Mutacional de DNA , DNA Mitocondrial/análise , Surdez/epidemiologia , Surdez/genética , Diabetes Mellitus/epidemiologia , Diabetes Mellitus/etiologia , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/genética , Feminino , França/epidemiologia , Frequência do Gene , Estudos de Associação Genética , Humanos , Lactente , Recém-Nascido , Síndrome MERRF/epidemiologia , Síndrome MERRF/genética , Masculino , Pessoa de Meia-Idade , Doenças Mitocondriais/complicações , Doenças Mitocondriais/epidemiologia , Fenótipo , Estudos Prospectivos
14.
Adv Exp Med Biol ; 1239: 317-330, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32451864

RESUMO

Hearing loss is both genetically and clinically heterogeneous, and pathogenic variants of over a hundred different genes are associated with this common neurosensory disorder. A relatively large number of these "deafness genes" encode myosin super family members. The evidence that pathogenic variants of human MYO3A, MYO6, MYO7A, MYO15A, MYH14 and MYH9 are associated with deafness ranges from moderate to definitive. Additional evidence for the involvement of these six myosins for normal hearing also comes from animal models, usually mouse or zebra fish, where mutations of these genes cause hearing loss and from biochemical, physiological and cell biological studies of their roles in the inner ear. This chapter focuses on these six genes for which evidence of a causative role in deafness is substantial.


Assuntos
Surdez , Audição , Miosinas , Animais , Surdez/genética , Audição/genética , Humanos , Mutação , Miosinas/genética
15.
Medicine (Baltimore) ; 99(17): e19774, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32332618

RESUMO

INTRODUCTION: There are many studies on the relationship between serum levels of hyperbilirubinemia and hearing impairment. However, the mechanism of hyperbilirubinemia on auditory impairment is not clear. METHODS AND ANALYSIS: A total of 1000 children with hyperbilirubinemia who are mainly indirectly elevated bilirubin in the full-term neonatal ward of Xiamen Children's Hospital from March 2020 to September 2020 will be enrolled. Using second-generation high-throughput sequencing technology, 127 deaf-related genes were sequenced from the collected samples. At the same time, physical audiometry was performed on the selected persons and audiometry data were recorded. DISCUSSION: In this study, we will combine gene sequencing with clinical indications of hyperbilirubinemia to find the loci suitable for high-frequency pathogenic deafness related to hyperbilirubinemia, so as to provide early guidance for deafness gene screening in children with hyperbilirubinemia. TRIAL REGISTRATION: Chinese Clinical trial registry: ChiCTR2000030075.


Assuntos
Protocolos Clínicos , Surdez/genética , Hiperbilirrubinemia Neonatal/genética , Distribuição de Qui-Quadrado , Correlação de Dados , Feminino , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Recém-Nascido , Masculino , Estudos Prospectivos
16.
Int J Pediatr Otorhinolaryngol ; 134: 110043, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32305661

RESUMO

INTRODUCTION: Congenital sensorineural hearing loss is a heterogeneous disorder; its etiological profile varies between populations. Pathogenic variants of GJB2 gene are the major cause of non-syndromic hearing loss. Congenital cytomegalovirus infection (cCMV) is the most important prenatal etiological factor causing hearing loss and other disorders. Perinatal events, syndromes, postnatal infections or traumas are less common. Causes of the remaining one third of hearing loss cases are unknown. OBJECTIVES: To determine the etiological profile of hearing loss in pediatric cochlear implant users in Lithuanian population. METHODS: The data of 122 children (70 male/52 female; aged 7.6 ± 3.3 years) cochlear implant users were analysed. Medical records of all children recruited in Santaros Clinics (Vilnius, Lithuania) were analysed to identify prenatal, perinatal, or postnatal risk factors based on the adapted list proposed by the Joint Committee of Infant Hearing. Genetic counselling and testing according to the scheme were performed to 101 children. DNA of 117 children was extracted from the DBS on Guthrie cards and CMV DNA detected using real time PCR. RESULTS: Non-syndromic hearing loss was diagnosed in 65 cases (53.3%), 58 of which were GJB2 gene-associated; syndromic hearing loss was diagnosed to 8 children (6.6%). Perinatal (prematurity, low birth weight, hypoxia, hyperbilirubinemia, sepsis, ototoxicity, and meningitis) and postnatal (meningitis) risk factors were associated with hearing loss in 16 (13.1%) and 4 (3.3%) study participants respectively. CMV DNA was detected in 12 samples (9.8%). The cause of hearing loss remained unknown only for 17 (13.9%) children. CONCLUSIONS: The major cause of HL in the current study was GJB2 gene alterations. Only 14% of the cohort had congenital hearing loss of unknown origin.


Assuntos
Implante Coclear , Conexinas/genética , Infecções por Citomegalovirus/complicações , Surdez/etiologia , Perda Auditiva Neurossensorial/etiologia , Adolescente , Criança , Pré-Escolar , Implantes Cocleares , Estudos de Coortes , Infecções por Citomegalovirus/congênito , Surdez/genética , Surdez/reabilitação , Feminino , Perda Auditiva Neurossensorial/genética , Perda Auditiva Neurossensorial/reabilitação , Humanos , Hiperbilirrubinemia Neonatal/complicações , Hipóxia/complicações , Lactente , Recém-Nascido de Baixo Peso , Recém-Nascido Prematuro , Lituânia , Masculino , Meningite/complicações , Sepse Neonatal/complicações
17.
Hum Genet ; 139(10): 1247-1259, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32306098

RESUMO

Congenital diarrheal disorders (CDD) comprise > 50 monogenic entities featuring chronic diarrhea of early-onset, including defects in nutrient and electrolyte absorption, enterocyte polarization, enteroendocrine cell differentiation, and epithelial integrity. Diarrhea is also a predominant symptom in many immunodeficiencies, congenital disorders of glycosylation, and in some defects of the vesicular sorting and transporting machinery. We set out to identify the etiology of an intractable diarrhea in 2 consanguineous families by whole-exome sequencing, and identified two novel AP1S1 mutations, c.269T>C (p.Leu90Pro) and c.346G>A (p.Glu116Lys). AP1S1 encodes the small subunit of the adaptor protein 1 complex (AP-1), which plays roles in clathrin coat-assembly and trafficking between trans-Golgi network, endosomes and the plasma membrane. An AP1S1 knock-out (KO) of a CaCo2 intestinal cell line was generated to characterize intestinal AP1S1 deficiency as well as identified mutations by stable expression in KO background. Morphology and prototype transporter protein distribution were comparable between parental and KO cells. We observed altered localization of tight-junction proteins ZO-1 and claudin 3, decreased transepithelial electrical resistance and an increased dextran permeability of the CaCo2-AP1S1-KO monolayer. In addition, lumen formation in 3D cultures of these cells was abnormal. Re-expression of wild-type AP1S1 in CaCo2-AP1S1-KO cells reverted these abnormalities, while expression of AP1S1 containing either missense mutation did not. Our data indicate that loss of AP1S1 function causes an intestinal epithelial barrier defect, and that AP1S1 mutations can cause a non-syndromic form of congenital diarrhea, whereas 2 reported truncating AP1S1 mutations caused MEDNIK syndrome, characterized by mental retardation, enteropathy, deafness, neuropathy, ichthyosis, and keratodermia.


Assuntos
Complexo 1 de Proteínas Adaptadoras/genética , Subunidades sigma do Complexo de Proteínas Adaptadoras/genética , Surdez/genética , Diarreia/genética , Ictiose/genética , Deficiência Intelectual/genética , Ceratodermia Palmar e Plantar/genética , Mutação de Sentido Incorreto , Complexo 1 de Proteínas Adaptadoras/deficiência , Subunidades sigma do Complexo de Proteínas Adaptadoras/deficiência , Sequência de Bases , Células CACO-2 , Claudina-3/genética , Claudina-3/metabolismo , Consanguinidade , Surdez/diagnóstico , Surdez/metabolismo , Surdez/patologia , Diarreia/diagnóstico , Diarreia/metabolismo , Diarreia/patologia , Feminino , Expressão Gênica , Técnicas de Inativação de Genes , Teste de Complementação Genética , Humanos , Ictiose/diagnóstico , Ictiose/metabolismo , Ictiose/patologia , Lactente , Recém-Nascido , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/metabolismo , Deficiência Intelectual/patologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Ceratodermia Palmar e Plantar/diagnóstico , Ceratodermia Palmar e Plantar/metabolismo , Ceratodermia Palmar e Plantar/patologia , Linhagem , Permeabilidade , Sequenciamento Completo do Exoma , Proteína da Zônula de Oclusão-1/genética , Proteína da Zônula de Oclusão-1/metabolismo
18.
Artigo em Chinês | MEDLINE | ID: mdl-32306631

RESUMO

Objective: To detect potential mutations in two Chinese families affected with deafness, so as provide prenatal diagnosis for them. Methods: Two Chinese families affected with deafness were identified at the genetic and prenatal diagnosis center of the First Affiliated Hospital of Zhengzhou University from March 2018 to December 2018.Mutation analyses were carried out by next generation sequencing (NGS),suspected mutations were verified by Sanger sequencing in the probands, unaffected relatives. Prenatal diagnosis for high-risk fetus were carried out through Sanger sequencing. Results: The proband of family 1 carried a c.432delA and a c.617-2_617-1insTC mutation of the TMPRSS3 gene, the proband of family 2 carried a c.271C>T(p.R91X) and a c.147dupTmutation ofthe TMPRSS3 gene, both parents of the two probands were carriers of heterozygous variants. Conclusions: Mutations in the TMPRSS3 gene are the suspected cause of deafness in two families. Application of next generation sequencing technologies make gene diagnosis of deafness efficiently and accurately and the molecular findings increase our understanding of the function of TMPRSS3 gene and enrich the human gene mutation database. It is helpful for recurrent genetic counseling and prenatal diagnosis for these families.


Assuntos
Surdez/diagnóstico , Surdez/genética , Proteínas de Membrana/genética , Proteínas de Neoplasias/genética , Diagnóstico Pré-Natal , Serina Endopeptidases/genética , Análise Mutacional de DNA , Feminino , Heterozigoto , Humanos , Mutação , Linhagem , Gravidez
19.
PLoS Genet ; 16(4): e1008643, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32294086

RESUMO

Hereditary hearing loss is challenging to diagnose because of the heterogeneity of the causative genes. Further, some genes involved in hereditary hearing loss have yet to be identified. Using whole-exome analysis of three families with congenital, severe-to-profound hearing loss, we identified a missense variant of SLC12A2 in five affected members of one family showing a dominant inheritance mode, along with de novo splice-site and missense variants of SLC12A2 in two sporadic cases, as promising candidates associated with hearing loss. Furthermore, we detected another de novo missense variant of SLC12A2 in a sporadic case. SLC12A2 encodes Na+, K+, 2Cl- cotransporter (NKCC) 1 and plays critical roles in the homeostasis of K+-enriched endolymph. Slc12a2-deficient mice have congenital, profound deafness; however, no human variant of SLC12A2 has been reported as associated with hearing loss. All identified SLC12A2 variants mapped to exon 21 or its 3'-splice site. In vitro analysis indicated that the splice-site variant generates an exon 21-skipped SLC12A2 mRNA transcript expressed at much lower levels than the exon 21-included transcript in the cochlea, suggesting a tissue-specific role for the exon 21-encoded region in the carboy-terminal domain. In vitro functional analysis demonstrated that Cl- influx was significantly decreased in all SLC12A2 variants studied. Immunohistochemistry revealed that SLC12A2 is located on the plasma membrane of several types of cells in the cochlea, including the strial marginal cells, which are critical for endolymph homeostasis. Overall, this study suggests that variants affecting exon 21 of the SLC12A2 transcript are responsible for hereditary hearing loss in humans.


Assuntos
Perda Auditiva Neurossensorial/congênito , Perda Auditiva Neurossensorial/genética , Mutação , Domínios Proteicos/genética , Membro 2 da Família 12 de Carreador de Soluto/química , Membro 2 da Família 12 de Carreador de Soluto/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Cloretos/metabolismo , Cóclea/metabolismo , Cóclea/patologia , Surdez/congênito , Surdez/genética , Éxons/genética , Feminino , Expressão Gênica , Células HEK293 , Humanos , Lactente , Macaca fascicularis , Masculino , Linhagem , Processamento de RNA , RNA Mensageiro/análise , RNA Mensageiro/genética , Membro 2 da Família 12 de Carreador de Soluto/metabolismo
20.
Nucleic Acids Res ; 48(9): 5065-5080, 2020 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-32249312

RESUMO

Disabling hearing loss impacts ∼466 million individuals worldwide with 34 million children affected. Gene and pharmacotherapeutic strategies to rescue auditory function in mouse models of human deafness are most effective when administered before hearing onset, after which therapeutic efficacy is significantly diminished or lost. We hypothesize that preemptive correction of a mutation in the fetal inner ear prior to maturation of the sensory epithelium will optimally restore sensory function. We previously demonstrated that transuterine microinjection of a splice-switching antisense oligonucleotide (ASO) into the amniotic cavity immediately surrounding the embryo on embryonic day 13-13.5 (E13-13.5) corrected pre-mRNA splicing in the juvenile Usher syndrome type 1c (Ush1c) mouse mutant. Here, we show that this strategy only marginally rescues hearing and partially rescues vestibular function. To improve therapeutic outcomes, we microinjected ASO directly into the E12.5 inner ear. A single intra-otic dose of ASO corrects harmonin RNA splicing, restores harmonin protein expression in sensory hair cell bundles, prevents hair cell loss, improves hearing sensitivity, and ameliorates vestibular dysfunction. Improvements in auditory and vestibular function were sustained well into adulthood. Our results demonstrate that an ASO pharmacotherapeutic administered to a developing organ system in utero preemptively corrects pre-mRNA splicing to abrogate the disease phenotype.


Assuntos
Proteínas de Ciclo Celular/genética , Proteínas do Citoesqueleto/genética , Surdez/congênito , Surdez/tratamento farmacológico , Oligonucleotídeos Antissenso/uso terapêutico , Vestíbulo do Labirinto/fisiopatologia , Âmnio , Animais , Limiar Auditivo/efeitos dos fármacos , Proteínas de Ciclo Celular/metabolismo , Proteínas do Citoesqueleto/metabolismo , Surdez/genética , Surdez/fisiopatologia , Orelha Interna/efeitos dos fármacos , Orelha Interna/metabolismo , Feto , Células Ciliadas Auditivas/efeitos dos fármacos , Células Ciliadas Auditivas/metabolismo , Células Ciliadas Auditivas/ultraestrutura , Camundongos , Microinjeções , Mutação , Oligonucleotídeos Antissenso/administração & dosagem , Processamento de RNA/efeitos dos fármacos , Vestíbulo do Labirinto/efeitos dos fármacos
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