Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 80
Filtrar
1.
Sci Rep ; 10(1): 13763, 2020 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-32792680

RESUMO

Mutations in the SNX14 gene cause spinocerebellar ataxia, autosomal recessive 20 (SCAR20) in both humans and dogs. Studies implicating the phenotypic consequences of SNX14 mutations to be consequences of subcellular disruption to autophagy and lipid metabolism have been limited to in vitro investigation of patient-derived dermal fibroblasts, laboratory engineered cell lines and developmental analysis of zebrafish morphants. SNX14 homologues Snz (Drosophila) and Mdm1 (yeast) have also been conducted, demonstrated an important biochemical role during lipid biogenesis. In this study we report the effect of loss of SNX14 in mice, which resulted in embryonic lethality around mid-gestation due to placental pathology that involves severe disruption to syncytiotrophoblast cell differentiation. In contrast to other vertebrates, zebrafish carrying a homozygous, maternal zygotic snx14 genetic loss-of-function mutation were both viable and anatomically normal. Whilst no obvious behavioural effects were observed, elevated levels of neutral lipids and phospholipids resemble previously reported effects on lipid homeostasis in other species. The biochemical role of SNX14 therefore appears largely conserved through evolution while the consequences of loss of function varies between species. Mouse and zebrafish models therefore provide valuable insights into the functional importance of SNX14 with distinct opportunities for investigating its cellular and metabolic function in vivo.

2.
Hum Mol Genet ; 29(11): 1882-1899, 2020 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-31998945

RESUMO

USH2A variants are the most common cause of Usher syndrome type 2, characterized by congenital sensorineural hearing loss and retinitis pigmentosa (RP), and also contribute to autosomal recessive non-syndromic RP. Several treatment strategies are under development; however, sensitive clinical trial endpoint metrics to determine therapeutic efficacy have not been identified. In the present study, we have performed longitudinal retrospective examination of the retinal and auditory symptoms in (i) 56 biallelic molecularly confirmed USH2A patients and (ii) ush2a mutant zebrafish to identify metrics for the evaluation of future clinical trials and rapid preclinical screening studies. The patient cohort showed a statistically significant correlation between age and both rate of constriction for the ellipsoid zone length and hyperautofluorescent outer retinal ring area. Visual acuity and pure tone audiograms are not suitable outcome measures. Retinal examination of the novel ush2au507 zebrafish mutant revealed a slowly progressive degeneration of predominantly rods, accompanied by rhodopsin and blue cone opsin mislocalization from 6 to 12 months of age with lysosome-like structures observed in the photoreceptors. This was further evaluated in the ush2armc zebrafish model, which revealed similar changes in photopigment mislocalization with elevated autophagy levels at 6 days post fertilization, indicating a more severe genotype-phenotype correlation and providing evidence of new insights into the pathophysiology underlying USH2A-retinal disease.

3.
Hum Mol Genet ; 28(22): 3815-3824, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31600780

RESUMO

Wolfram syndrome (WS) is a heterogeneous multisystem neurodegenerative disorder with two allelic variations in addition to a separate subtype known as WS type 2. The wide phenotypic spectrum of WS includes diabetes mellitus and optic atrophy which is often accompanied by diabetes insipidus, deafness, urological and neurological complications in combination or in isolation. To date, the understanding of the genotype-phenotype relationship in this complex syndrome remains poorly understood. In this study, we identified and explored the functionality of rare and novel variants in the two causative WS genes WFS1 and CISD2 by assessing the effects of the mutations on the encoded proteins Wolframin and ERIS, in a cohort of 12 patients with autosomal recessive WS, dominant WS and WS type 2. The identified pathogenic variants included missense changes, frameshift deletions and insertions in WFS1 and an exonic deletion in CISD2 which all altered the respective encoded protein in a manner that did not correlate to the phenome previously described. These observations suggest the lack of genotype-phenotype correlation in this complex syndrome and the need to explore other molecular genetic mechanisms. Additionally, our findings highlight the importance of functionally assessing variants for their pathogenicity to tackle the problem of increasing variants of unknown significance in the public genetic databases.


Assuntos
Proteínas de Membrana/genética , Síndrome de Wolfram/genética , Adolescente , Adulto , Alelos , Éxons , Feminino , Mutação da Fase de Leitura , Estudos de Associação Genética , Humanos , Masculino , Proteínas de Membrana/metabolismo , Mutação , Atrofia Óptica/genética , Linhagem , Fenótipo , Síndrome de Wolfram/fisiopatologia
4.
Hum Mol Genet ; 28(20): 3466-3474, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31504499

RESUMO

Recurrent pregnancy loss (RPL) is defined as two or more consecutive miscarriages and affects an estimated 1.5% of couples trying to conceive. RPL has been attributed to genetic, endocrine, immune and thrombophilic disorders, but many cases remain unexplained. We investigated a Bangladeshi family where the proband experienced 29 consecutive pregnancy losses with no successful pregnancies from three different marriages. Whole exome sequencing identified rare genetic variants in several candidate genes. These were further investigated in Asian and white European RPL cohorts, and in Bangladeshi controls. FKBP4, encoding the immunophilin FK506-binding protein 4, was identified as a plausible candidate, with three further novel variants identified in Asian patients. None were found in European patients or controls. In silico structural studies predicted damaging effects of the variants in the structure-function properties of the FKBP52 protein. These were located within domains reported to be involved in Hsp90 binding and peptidyl-prolyl cis-trans isomerase (PPIase) activity. Profound effects on PPIase activity were demonstrated in transiently transfected HEK293 cells comparing wild-type and mutant FKBP4 constructs. Mice lacking FKBP4 have been previously reported as infertile through implantation failure. This study therefore strongly implicates FKBP4 as associated with fetal losses in humans, particularly in the Asian population.


Assuntos
Aborto Habitual/genética , Proteínas de Ligação a Tacrolimo/genética , Sequenciamento Completo do Exoma/métodos , Exoma/genética , Feminino , Predisposição Genética para Doença , Células HEK293 , Humanos , Mutação de Sentido Incorreto/genética , Linhagem , Gravidez , Estrutura Secundária de Proteína
5.
Genes (Basel) ; 10(7)2019 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-31336982

RESUMO

Labyrinthine aplasia, microtia, and microdontia (LAMM) is an autosomal recessive condition causing profound congenital deafness, complete absence of inner ear structures (usually Michel's aplasia), microtia (usually type 1) and microdontia. To date, several families have been described with this condition and a number of mutations has been reported. We report on eight further cases of LAMM syndrome including three novel mutations, c. 173T>C p.L58P; c. 284G>A p.(Arg95Gln) and c.325_327delinsA p.(Glu109Thrfs*18). Congenital deafness was the primary presenting feature in all affected individuals and consanguinity in all but two families. We compare the features in our patients to those previously reported in LAMM, and describe a milder, asymmetrical phenotype associated with FGF3 mutations.


Assuntos
Microtia Congênita/genética , Microtia Congênita/patologia , Orelha Interna/anormalidades , Fator 3 de Crescimento de Fibroblastos/genética , Perda Auditiva Neurossensorial/genética , Perda Auditiva Neurossensorial/patologia , Anormalidades Dentárias/genética , Anormalidades Dentárias/patologia , Adulto , Pré-Escolar , Consanguinidade , Análise Mutacional de DNA , Surdez/congênito , Orelha Interna/patologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Mutação , Fenótipo
6.
Science ; 364(6442)2019 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-31123110

RESUMO

Approximately 2.4% of the human mitochondrial DNA (mtDNA) genome exhibits common homoplasmic genetic variation. We analyzed 12,975 whole-genome sequences to show that 45.1% of individuals from 1526 mother-offspring pairs harbor a mixed population of mtDNA (heteroplasmy), but the propensity for maternal transmission differs across the mitochondrial genome. Over one generation, we observed selection both for and against variants in specific genomic regions; known variants were more likely to be transmitted than previously unknown variants. However, new heteroplasmies were more likely to match the nuclear genetic ancestry as opposed to the ancestry of the mitochondrial genome on which the mutations occurred, validating our findings in 40,325 individuals. Thus, human mtDNA at the population level is shaped by selective forces within the female germ line under nuclear genetic control, which ensures consistency between the two independent genetic lineages.


Assuntos
DNA Mitocondrial/genética , Genoma Mitocondrial , Herança Materna , Óvulo/crescimento & desenvolvimento , Seleção Genética , Feminino , Variação Genética , Humanos
7.
Ophthalmology ; 126(6): 888-907, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30653986

RESUMO

PURPOSE: To develop a comprehensive next-generation sequencing panel assay that screens genes known to cause developmental eye disorders and inherited eye disease and to evaluate its diagnostic yield in a pediatric cohort with malformations of the globe, anterior segment anomalies, childhood glaucoma, or a combination thereof. DESIGN: Evaluation of diagnostic test. PARTICIPANTS: Two hundred seventy-seven children, 0 to 16 years of age, diagnosed with nonsyndromic or syndromic developmental eye defects without a genetic diagnosis. METHODS: We developed a new oculome panel using a custom-designed Agilent SureSelect QXT target capture method (Agilent Technologies, Santa Clara, CA) to capture and perform parallel high-throughput sequencing analysis of 429 genes associated with eye disorders. Bidirectional Sanger sequencing confirmed suspected pathogenic variants. MAIN OUTCOME MEASURES: Collated clinical details and oculome molecular genetic results. RESULTS: The oculome design covers 429 known eye disease genes; these are subdivided into 5 overlapping virtual subpanels for anterior segment developmental anomalies including glaucoma (ASDA; 59 genes), microphthalmia-anophthalmia-coloboma (MAC; 86 genes), congenital cataracts and lens-associated conditions (70 genes), retinal dystrophies (RET; 235 genes), and albinism (15 genes), as well as additional genes implicated in optic atrophy and complex strabismus (10 genes). Panel development and testing included analyzing 277 clinical samples and 3 positive control samples using Illumina sequencing platforms; more than 30× read depth was achieved for 99.5% of the targeted 1.77-Mb region. Bioinformatics analysis performed using a pipeline based on Freebayes and ExomeDepth to identify coding sequence and copy number variants, respectively, resulted in a definitive diagnosis in 68 of 277 samples, with variability in diagnostic yield between phenotypic subgroups: MAC, 8.2% (8 of 98 cases solved); ASDA, 24.8% (28 of 113 cases solved); other or syndromic, 37.5% (3 of 8 cases solved); RET, 42.8% (21 of 49 cases solved); and congenital cataracts and lens-associated conditions, 88.9% (8 of 9 cases solved). CONCLUSIONS: The oculome test diagnoses a comprehensive range of genetic conditions affecting the development of the eye, potentially replacing protracted and costly multidisciplinary assessments and allowing for faster targeted management. The oculome enabled molecular diagnosis of a significant number of cases in our sample cohort of varied ocular birth defects.


Assuntos
Variações do Número de Cópias de DNA/genética , Anormalidades do Olho/diagnóstico , Anormalidades do Olho/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Técnicas de Diagnóstico Molecular , Mutação/genética , Proteoma/genética , Adolescente , Criança , Pré-Escolar , Feminino , Genoma Humano , Humanos , Lactente , Recém-Nascido , Masculino , Linhagem
8.
Genet Med ; 21(5): 1083-1091, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30270361

RESUMO

PURPOSE: Little is known about how health-care professionals communicate with patients about consenting to genome sequencing. We therefore examined what topics health-care professionals covered and what questions patients asked during consent conversations. METHODS: Twenty-one genome sequencing consent appointments were audio recorded and analyzed. Participants were 35 individuals being invited to participate in the 100,000 Genomes Project (14 participants with rare diseases, 21 relatives), and 10 health-care professionals ("consenters"). RESULTS: Two-thirds of participants' questions were substantive (e.g., genetics and inheritance); one-third administrative (e.g., filling in the consent form). Consenters usually (19/21) emphasized participant choice about secondary findings, but less often (13/21) emphasized the uncertainty about associated disease risks. Consenters primarily used passive statements and closed-ended, rather than open-ended, questions to invite participants' questions and concerns. In two appointments, one parent expressed negative or uncertain views about secondary findings, but after discussion with the other parent opted to receive them. CONCLUSION: Health-care professionals need to be prepared to answer patients' questions about genetics to facilitate genome sequencing consent. Health-care professionals' education also needs to address how to effectively listen and elicit each patient's questions and views, and how to discuss uncertainty around the disease risks associated with secondary findings.


Assuntos
Consentimento Livre e Esclarecido/ética , Sequenciamento Completo do Genoma/ética , Adulto , Idoso , Comunicação , Termos de Consentimento/ética , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Pessoal de Saúde , Humanos , Consentimento Livre e Esclarecido/normas , Masculino , Pessoa de Meia-Idade , Pais , Pacientes , Sequenciamento Completo do Genoma/métodos
9.
J Med Genet ; 55(11): 721-728, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30049826

RESUMO

BACKGROUND: Rare genetic conditions are frequent risk factors for, or direct causes of, paediatric intensive care unit (PICU) admission. Such conditions are frequently suspected but unidentified at PICU admission. Compassionate and effective care is greatly assisted by definitive diagnostic information. There is therefore a need to provide a rapid genetic diagnosis to inform clinical management.To date, whole genome sequencing (WGS) approaches have proved successful in diagnosing a proportion of children with rare diseases, but results may take months to report. Our aim was to develop an end-to-end workflow for the use of rapid WGS for diagnosis in critically ill children in a UK National Health Service (NHS) diagnostic setting. METHODS: We sought to establish a multidisciplinary Rapid Paediatric Sequencing team for case selection, trio WGS, rapid bioinformatics sequence analysis and a phased analysis and reporting system to prioritise genes with a high likelihood of being causal. RESULTS: Trio WGS in 24 critically ill children led to a molecular diagnosis in 10 (42%) through the identification of causative genetic variants. In 3 of these 10 individuals (30%), the diagnostic result had an immediate impact on the individual's clinical management. For the last 14 trios, the shortest time taken to reach a provisional diagnosis was 4 days (median 8.5 days). CONCLUSION: Rapid WGS can be used to diagnose and inform management of critically ill children within the constraints of an NHS clinical diagnostic setting. We provide a robust workflow that will inform and facilitate the rollout of rapid genome sequencing in the NHS and other healthcare systems globally.


Assuntos
Estado Terminal , Doenças Genéticas Inatas/diagnóstico , Doenças Genéticas Inatas/genética , Sequenciamento Completo do Genoma , Criança , Gerenciamento Clínico , Estudo de Associação Genômica Ampla/métodos , Estudo de Associação Genômica Ampla/normas , Humanos , Unidades de Terapia Intensiva Pediátrica , Doenças Raras , Sequenciamento Completo do Genoma/métodos , Fluxo de Trabalho
10.
Am J Hum Genet ; 102(6): 1195-1203, 2018 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-29861108

RESUMO

Next-generation sequencing is a powerful tool for the discovery of genes related to neurodevelopmental disorders (NDDs). Here, we report the identification of a distinct syndrome due to de novo or inherited heterozygous mutations in Tousled-like kinase 2 (TLK2) in 38 unrelated individuals and two affected mothers, using whole-exome and whole-genome sequencing technologies, matchmaker databases, and international collaborations. Affected individuals had a consistent phenotype, characterized by mild-borderline neurodevelopmental delay (86%), behavioral disorders (68%), severe gastro-intestinal problems (63%), and facial dysmorphism including blepharophimosis (82%), telecanthus (74%), prominent nasal bridge (68%), broad nasal tip (66%), thin vermilion of the upper lip (62%), and upslanting palpebral fissures (55%). Analysis of cell lines from three affected individuals showed that mutations act through a loss-of-function mechanism in at least two case subjects. Genotype-phenotype analysis and comparison of computationally modeled faces showed that phenotypes of these and other individuals with loss-of-function variants significantly overlapped with phenotypes of individuals with other variant types (missense and C-terminal truncating). This suggests that haploinsufficiency of TLK2 is the most likely underlying disease mechanism, leading to a consistent neurodevelopmental phenotype. This work illustrates the power of international data sharing, by the identification of 40 individuals from 26 different centers in 7 different countries, allowing the identification, clinical delineation, and genotype-phenotype evaluation of a distinct NDD caused by mutations in TLK2.


Assuntos
Estudos de Associação Genética , Padrões de Herança/genética , Mutação com Perda de Função/genética , Transtornos do Neurodesenvolvimento/genética , Proteínas Quinases/genética , Adolescente , Adulto , Sequência de Bases , Linhagem Celular , Criança , Pré-Escolar , Facies , Feminino , Humanos , Lactente , Masculino , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Translocação Genética , Adulto Jovem
11.
Hum Mol Genet ; 27(11): 1927-1940, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29635513

RESUMO

Mutations in SNX14 cause the autosomal recessive cerebellar ataxia 20 (SCAR20). Mutations generally result in loss of protein although several coding region deletions have also been reported. Patient-derived fibroblasts show disrupted autophagy, but the precise function of SNX14 is unknown. The yeast homolog, Mdm1, functions in endoplasmic reticulum (ER)-lysosome/vacuole inter-organelle tethering, but functional conservation in mammals is still required. Here, we show that loss of SNX14 alters but does not block autophagic flux. In addition, we find that SNX14 is an ER-associated protein that functions in neutral lipid homeostasis and inter-organelle crosstalk. SNX14 requires its N-terminal transmembrane helices for ER localization, while the Phox homology (PX) domain is dispensable for subcellular localization. Both SNX14-mutant fibroblasts and SNX14KO HEK293 cells accumulate aberrant cytoplasmic vacuoles, suggesting defects in endolysosomal homeostasis. However, ER-late endosome/lysosome contact sites are maintained in SNX14KO cells, indicating that it is not a prerequisite for ER-endolysosomal tethering. Further investigation of SNX14- deficiency indicates general defects in neutral lipid metabolism. SNX14KO cells display distinct perinuclear accumulation of filipin in LAMP1-positive lysosomal structures indicating cholesterol accumulation. Consistent with this, SNX14KO cells display a slight but detectable decrease in cholesterol ester levels, which is exacerbated with U18666A. Finally, SNX14 associates with ER-derived lipid droplets (LD) following oleate treatment, indicating a role in ER-LD crosstalk. We therefore identify an important role for SNX14 in neutral lipid homeostasis between the ER, lysosomes and LDs that may provide an early intervention target to alleviate the clinical symptoms of SCAR20.


Assuntos
Retículo Endoplasmático/genética , Metabolismo dos Lipídeos/genética , Nexinas de Classificação/genética , Ataxias Espinocerebelares/genética , Autofagia/genética , Retículo Endoplasmático/metabolismo , Endossomos , Técnicas de Inativação de Genes , Células HEK293 , Homeostase/efeitos dos fármacos , Humanos , Proteínas de Filamentos Intermediários/genética , Gotículas Lipídicas/metabolismo , Lisossomos/efeitos dos fármacos , Lisossomos/genética , Mutação , Ácido Oleico/farmacologia , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Nexinas de Classificação/deficiência , Nexinas de Classificação/metabolismo , Ataxias Espinocerebelares/metabolismo , Ataxias Espinocerebelares/fisiopatologia
13.
Hum Genet ; 137(2): 111-127, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29305691

RESUMO

Cerebellar ataxia, areflexia, pes cavus, optic atrophy and sensorineural hearing impairment (CAPOS) is a rare clinically distinct syndrome caused by a single dominant missense mutation, c.2452G>A, p.Glu818Lys, in ATP1A3, encoding the neuron-specific alpha subunit of the Na+/K+-ATPase α3. Allelic mutations cause the neurological diseases rapid dystonia Parkinsonism and alternating hemiplegia of childhood, disorders which do not encompass hearing or visual impairment. We present detailed clinical phenotypic information in 18 genetically confirmed patients from 11 families (10 previously unreported) from Denmark, Sweden, UK and Germany indicating a specific type of hearing impairment-auditory neuropathy (AN). All patients were clinically suspected of CAPOS and had hearing problems. In this retrospective analysis of audiological data, we show for the first time that cochlear outer hair cell activity was preserved as shown by the presence of otoacoustic emissions and cochlear microphonic potentials, but the auditory brainstem responses were grossly abnormal, likely reflecting neural dyssynchrony. Poor speech perception was observed, especially in noise, which was beyond the hearing level obtained in the pure tone audiograms in several of the patients presented here. Molecular modelling and in vitro electrophysiological studies of the specific CAPOS mutation were performed. Heterologous expression studies of α3 with the p.Glu818Lys mutation affects sodium binding to, and release from, the sodium-specific site in the pump, the third ion-binding site. Molecular dynamics simulations confirm that the structure of the C-terminal region is affected. In conclusion, we demonstrate for the first time evidence for auditory neuropathy in CAPOS syndrome, which may reflect impaired propagation of electrical impulses along the spiral ganglion neurons. This has implications for diagnosis and patient management. Auditory neuropathy is difficult to treat with conventional hearing aids, but preliminary improvement in speech perception in some patients suggests that cochlear implantation may be effective in CAPOS patients.


Assuntos
Ataxia Cerebelar/genética , Deformidades Congênitas do Pé/genética , Perda Auditiva Central/genética , Perda Auditiva Neurossensorial/genética , Atrofia Óptica/genética , Reflexo Anormal/genética , ATPase Trocadora de Sódio-Potássio/genética , Adolescente , Adulto , Ataxia Cerebelar/epidemiologia , Ataxia Cerebelar/fisiopatologia , Criança , Pré-Escolar , Dinamarca/epidemiologia , Feminino , Deformidades Congênitas do Pé/epidemiologia , Deformidades Congênitas do Pé/fisiopatologia , Alemanha/epidemiologia , Perda Auditiva Central/epidemiologia , Perda Auditiva Central/fisiopatologia , Perda Auditiva Neurossensorial/epidemiologia , Perda Auditiva Neurossensorial/fisiopatologia , Humanos , Masculino , Simulação de Dinâmica Molecular , Mutação de Sentido Incorreto/genética , Atrofia Óptica/epidemiologia , Atrofia Óptica/fisiopatologia , Fenótipo , Estudos Retrospectivos , ATPase Trocadora de Sódio-Potássio/química , Suécia/epidemiologia , Adulto Jovem
14.
Orphanet J Rare Dis ; 12(1): 24, 2017 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-28173822

RESUMO

BACKGROUND: We describe molecular diagnosis in a complex consanguineous family: four offspring presented with combinations of three distinctive phenotypes; non-syndromic hearing loss (NSHL), an unusual skeletal phenotype comprising multiple fractures, cranial abnormalities and diaphyseal expansion, and significant developmental delay with microcephaly. We performed Chromosomal Microarray Analysis on the offspring with either the skeletal or developmental delay phenotypes, and linkage analysis and whole exome sequencing (WES) on all four children, parents and maternal aunt. RESULTS: Chromosomal microarray and FISH analysis identified a de novo unbalanced translocation as a cause of the microcephaly and severe developmental delay. WES identified a NSHL-causing splice variant in an autosomal recessive deafness gene PDZD7 which resided in a linkage region and affected three of the children. In the two children diagnosed with an unusual skeletal phenotype, WES eventually disclosed a heterozygous COL1A1 variant which affects C-propetide cleavage site of COL1. The variant was inherited from an apparently unaffected mosaic father in an autosomal dominant fashion. After the discovery of the COL1A1 variant, the skeletal phenotype was diagnosed as a high bone mass form of osteogenesis imperfecta. CONCLUSIONS: Next generation sequencing offers an unbiased approach to molecular genetic diagnosis in highly heterogeneous and poorly characterised disorders and enables early diagnosis as well as detection of mosaicism.


Assuntos
Genômica , Perda Auditiva/genética , Doenças Raras/genética , Pré-Escolar , Consanguinidade , Deficiências do Desenvolvimento , Regulação da Expressão Gênica , Humanos , Mutação , Irmãos , Sequenciamento Completo do Exoma
15.
Am J Hum Genet ; 100(1): 75-90, 2017 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-28041643

RESUMO

Inherited retinal disease is a common cause of visual impairment and represents a highly heterogeneous group of conditions. Here, we present findings from a cohort of 722 individuals with inherited retinal disease, who have had whole-genome sequencing (n = 605), whole-exome sequencing (n = 72), or both (n = 45) performed, as part of the NIHR-BioResource Rare Diseases research study. We identified pathogenic variants (single-nucleotide variants, indels, or structural variants) for 404/722 (56%) individuals. Whole-genome sequencing gives unprecedented power to detect three categories of pathogenic variants in particular: structural variants, variants in GC-rich regions, which have significantly improved coverage compared to whole-exome sequencing, and variants in non-coding regulatory regions. In addition to previously reported pathogenic regulatory variants, we have identified a previously unreported pathogenic intronic variant in CHM in two males with choroideremia. We have also identified 19 genes not previously known to be associated with inherited retinal disease, which harbor biallelic predicted protein-truncating variants in unsolved cases. Whole-genome sequencing is an increasingly important comprehensive method with which to investigate the genetic causes of inherited retinal disease.


Assuntos
Análise Mutacional de DNA , Variação Genética/genética , Genoma Humano/genética , Doenças Retinianas/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Alelos , Sequência de Bases , Coroideremia/genética , Grupos Étnicos/genética , Exoma/genética , Feminino , Genes Recessivos/genética , Humanos , Íntrons/genética , Masculino , Mutação , Doenças Raras/genética
16.
Nat Rev Dis Primers ; 3: 16094, 2017 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-28079113

RESUMO

Congenital hearing loss (hearing loss that is present at birth) is one of the most prevalent chronic conditions in children. In the majority of developed countries, neonatal hearing screening programmes enable early detection; early intervention will prevent delays in speech and language development and has long-lasting beneficial effects on social and emotional development and quality of life. A diagnosis of hearing loss is usually followed by a search for an underlying aetiology. Congenital hearing loss might be attributed to environmental and prenatal factors, which prevail in low-income settings; congenital infections, particularly cytomegalovirus infection, are also a common risk factor for hearing loss. Genetic causes probably account for the majority of cases in developed countries; mutations can affect any component of the hearing pathway, in particular, inner ear homeostasis (endolymph production and maintenance) and mechano-electrical transduction (the conversion of a mechanical stimulus into electrochemical activity). Once the underlying cause of hearing loss is established, it might direct therapeutic decision making and guide prevention and (genetic) counselling. Management options include specific antimicrobial therapies, surgical treatment of craniofacial abnormalities and implantable or non-implantable hearing devices. An improved understanding of the pathophysiology and molecular mechanisms that underlie hearing loss and increased awareness of recent advances in genetic testing will promote the development of new treatment and screening strategies.


Assuntos
Perda Auditiva/congênito , Animais , Perda Auditiva/epidemiologia , Perda Auditiva/fisiopatologia , Perda Auditiva/virologia , Humanos , Recém-Nascido , Fatores de Risco
19.
Hum Mutat ; 37(8): 812-9, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27068579

RESUMO

Although there are nearly 100 different causative genes identified for nonsyndromic hearing loss (NSHL), Sanger sequencing-based DNA diagnostics usually only analyses three, namely, GJB2, SLC26A4, and OTOF. As this is seen as inadequate, there is a need for high-throughput diagnostic methods to detect disease-causing variations, including single-nucleotide variations (SNVs), insertions/deletions (Indels), and copy-number variations (CNVs). In this study, a targeted resequencing panel for hearing loss was developed including 79 genes for NSHL and selected forms of syndromic hearing loss. One-hundred thirty one presumed autosomal-recessive NSHL (arNSHL) patients of Western-European ethnicity were analyzed for SNVs, Indels, and CNVs. In addition, we established a straightforward variant classification system to deal with the large number of variants encountered. We estimate that combining prescreening of GJB2 with our panel leads to a diagnosis in 25%-30% of patients. Our data show that after GJB2, the most commonly mutated genes in a Western-European population are TMC1, MYO15A, and MYO7A (3.1%). CNV analysis resulted in the identification of causative variants in two patients in OTOA and STRC. One of the major challenges for diagnostic gene panels is assigning pathogenicity for variants. A collaborative database collecting all identified variants from multiple centers could be a valuable resource for hearing loss diagnostics.


Assuntos
Predisposição Genética para Doença , Perda Auditiva Neurossensorial/diagnóstico , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Mutação , Análise de Sequência de DNA/métodos , Conexinas/genética , Variações do Número de Cópias de DNA , Exoma , Proteínas Ligadas por GPI/genética , Perda Auditiva Neurossensorial/genética , Humanos , Mutação INDEL , Peptídeos e Proteínas de Sinalização Intercelular , Proteínas de Membrana/genética , Miosina VIIa , Miosinas/genética , Polimorfismo de Nucleotídeo Único
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA