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1.
Sci Rep ; 14(1): 22539, 2024 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-39341923

RESUMO

Cerebral vasospasm (CVS) is an important contributor to delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage (aSAH), leading to high morbidity and long-term disability. While several microRNAs (miRNAs) have been implicated in vasospasm, the underlying mechanisms for CVS remain poorly understood. Our study aims to identify miRNAs that may contribute to the development of CVS. Whole-blood samples were obtained during or outside of vasospasm from aSAH patients whose maximal vasospasm was moderate or severe. MiRNAs were isolated from serial whole-blood samples, and miRNA sequencing was performed. Differentially expressed miRNAs were identified and the expression levels in patients' samples were verified using real-time qPCR. The biological functions of identified miRNA were evaluated in human brain endothelial cells (HBECs). MiRNA profiling revealed significant upregulation of miR-148b-3p in patients during CVS. We demonstrated that miR-148b-3p directly targeted and decreased the expression of ROCK1, affecting cell proliferation, migration, and invasion of HBECs through the ROCK-LIMK-Cofilin pathway. We propose that the upregulation of miRNA-148b-3p plays a role in the development of CVS by regulating actin cytoskeletal dynamics in HBECs, which is crucial for vascular function. Our study highlights miR-148b-3p as a potential diagnostic marker as well as therapeutic target for CVS following aSAH.


Assuntos
Células Endoteliais , Perfilação da Expressão Gênica , MicroRNAs , Hemorragia Subaracnóidea , Vasoespasmo Intracraniano , Quinases Associadas a rho , MicroRNAs/genética , MicroRNAs/metabolismo , Humanos , Hemorragia Subaracnóidea/genética , Hemorragia Subaracnóidea/complicações , Hemorragia Subaracnóidea/metabolismo , Vasoespasmo Intracraniano/genética , Vasoespasmo Intracraniano/metabolismo , Vasoespasmo Intracraniano/etiologia , Pessoa de Meia-Idade , Feminino , Masculino , Quinases Associadas a rho/metabolismo , Quinases Associadas a rho/genética , Células Endoteliais/metabolismo , Proliferação de Células , Movimento Celular/genética , Idoso , Adulto , Regulação da Expressão Gênica
2.
medRxiv ; 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38946951

RESUMO

In recent years, there has been increased focus on exploring the role the non-protein-coding genome plays in Mendelian disorders. One class of particular interest is long non-coding RNAs (lncRNAs), which has recently been implicated in the regulation of diverse molecular processes. However, because lncRNAs do not encode protein, there is uncertainty regarding what constitutes a pathogenic lncRNA variant, and thus annotating such elements is challenging. The Developmental Genome Anatomy Project (DGAP) and similar projects recruit individuals with apparently balanced chromosomal abnormalities (BCAs) that disrupt or dysregulate genes in order to annotate the human genome. We hypothesized that rearrangements disrupting lncRNAs could be the underlying genetic etiology for the phenotypes of a subset of these individuals. Thus, we assessed 279 cases with BCAs and selected 191 cases with simple BCAs (breakpoints at only two genomic locations) for further analysis of lncRNA disruptions. From these, we identified 66 cases in which the chromosomal rearrangements directly disrupt lncRNAs. Strikingly, the lncRNAs MEF2C-AS1 and ENSG00000257522 are each disrupted in two unrelated cases. Furthermore, in 30 cases, no genes of any other class aside from lncRNAs are directly disrupted, consistent with the hypothesis that lncRNA disruptions could underly the phenotypes of these individuals. To showcase the power of this genomic approach for annotating lncRNAs, here we focus on clinical reports and genetic analysis of two individuals with BCAs and additionally highlight six individuals with likely developmental etiologies due to lncRNA disruptions.

3.
Hum Genet ; 143(7): 921-938, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39060644

RESUMO

In recent years, there has been increased focus on exploring the role the non-protein-coding genome plays in Mendelian disorders. One class of particular interest is long non-coding RNAs (lncRNAs), which has recently been implicated in the regulation of diverse molecular processes. However, because lncRNAs do not encode protein, there is uncertainty regarding what constitutes a pathogenic lncRNA variant, and thus annotating such elements is challenging. The Developmental Genome Anatomy Project (DGAP) and similar projects recruit individuals with apparently balanced chromosomal abnormalities (BCAs) that disrupt or dysregulate genes in order to annotate the human genome. We hypothesized that rearrangements disrupting lncRNAs could be the underlying genetic etiology for the phenotypes of a subset of these individuals. Thus, we assessed 279 cases with BCAs and selected 191 cases with simple BCAs (breakpoints at only two genomic locations) for further analysis of lncRNA disruptions. From these, we identified 66 cases in which the chromosomal rearrangements directly disrupt lncRNAs. In 30 cases, no genes of any other class aside from lncRNAs are directly disrupted, consistent with the hypothesis that lncRNA disruptions could underly the phenotypes of these individuals. Strikingly, the lncRNAs MEF2C-AS1 and ENSG00000257522 are each disrupted in two unrelated cases. Furthermore, we experimentally tested the lncRNAs TBX2-AS1 and MEF2C-AS1 and found that knockdown of these lncRNAs resulted in decreased expression of the neighboring transcription factors TBX2 and MEF2C, respectively. To showcase the power of this genomic approach for annotating lncRNAs, here we focus on clinical reports and genetic analysis of seven individuals with likely developmental etiologies due to lncRNA disruptions.


Assuntos
Fatores de Transcrição MEF2 , RNA Longo não Codificante , Humanos , RNA Longo não Codificante/genética , Fatores de Transcrição MEF2/genética , Feminino , Aberrações Cromossômicas , Masculino , Genoma Humano , Fenótipo , Mutação em Linhagem Germinativa
4.
JAMA Cardiol ; 9(3): 263-271, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38294787

RESUMO

Importance: Familial hypercholesterolemia (FH) is a genetic disorder that often results in severely high low-density lipoprotein cholesterol (LDL-C) and high risk of premature coronary heart disease (CHD). However, the impact of FH variants on CHD risk among individuals with moderately elevated LDL-C is not well quantified. Objective: To assess CHD risk associated with FH variants among individuals with moderately (130-189 mg/dL) and severely (≥190 mg/dL) elevated LDL-C and to quantify excess CHD deaths attributable to FH variants in US adults. Design, Setting, and Participants: A total of 21 426 individuals without preexisting CHD from 6 US cohort studies (Atherosclerosis Risk in Communities study, Coronary Artery Risk Development in Young Adults study, Cardiovascular Health Study, Framingham Heart Study Offspring cohort, Jackson Heart Study, and Multi-Ethnic Study of Atherosclerosis) were included, 63 of whom had an FH variant. Data were collected from 1971 to 2018, and the median (IQR) follow-up was 18 (13-28) years. Data were analyzed from March to May 2023. Exposures: LDL-C, cumulative past LDL-C, FH variant status. Main Outcomes and Measures: Cox proportional hazards models estimated associations between FH variants and incident CHD. The Cardiovascular Disease Policy Model projected excess CHD deaths associated with FH variants in US adults. Results: Of the 21 426 individuals without preexisting CHD (mean [SD] age 52.1 [15.5] years; 12 041 [56.2%] female), an FH variant was found in 22 individuals with moderately elevated LDL-C (0.3%) and in 33 individuals with severely elevated LDL-C (2.5%). The adjusted hazard ratios for incident CHD comparing those with and without FH variants were 2.9 (95% CI, 1.4-6.0) and 2.6 (95% CI, 1.4-4.9) among individuals with moderately and severely elevated LDL-C, respectively. The association between FH variants and CHD was slightly attenuated when further adjusting for baseline LDL-C level, whereas the association was no longer statistically significant after adjusting for cumulative past LDL-C exposure. Among US adults 20 years and older with no history of CHD and LDL-C 130 mg/dL or higher, more than 417 000 carry an FH variant and were projected to experience more than 12 000 excess CHD deaths in those with moderately elevated LDL-C and 15 000 in those with severely elevated LDL-C compared with individuals without an FH variant. Conclusions and Relevance: In this pooled cohort study, the presence of FH variants was associated with a 2-fold higher CHD risk, even when LDL-C was only moderately elevated. The increased CHD risk appeared to be largely explained by the higher cumulative LDL-C exposure in individuals with an FH variant compared to those without. Further research is needed to assess the value of adding genetic testing to traditional phenotypic FH screening.


Assuntos
Aterosclerose , Doenças Cardiovasculares , Doença da Artéria Coronariana , Hipercolesterolemia , Hiperlipoproteinemia Tipo II , Adulto Jovem , Humanos , Feminino , Pessoa de Meia-Idade , Masculino , Hipercolesterolemia/complicações , LDL-Colesterol/genética , Doenças Cardiovasculares/prevenção & controle , Estudos de Coortes , Fatores de Risco , Hiperlipoproteinemia Tipo II/diagnóstico , Doença da Artéria Coronariana/complicações , Aterosclerose/complicações , Fatores de Risco de Doenças Cardíacas
6.
Hum Mutat ; 43(12): 1837-1843, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35870179

RESUMO

Synonymous variants have been shown to alter the correct splicing of pre-mRNAs and generate disease-causing transcripts. These variants are not an uncommon etiology of genetic disease; however, they are frequently overlooked during genetic testing in the absence of functional and clinical data. Here, we describe the occurrence of a synonymous variant [NM_005422.4 (TECTA):c.327C>T, p.(Gly109=)] in seven individuals with hearing loss from six unrelated families. The variant is not located near exonic/intronic boundaries but is predicted to impact splicing by activating a cryptic splicing donor site in exon 4 of TECTA. In vitro minigene assays show that the variant disrupts the reading frame of the canonical transcript, which is predicted to cause a premature termination codon 48 amino acids downstream of the variant, leading to nonsense-mediated decay. The variant is present in population databases, predominantly in Latinos of African ancestry, but is rare in other ethnic groups. Our findings suggest that this synonymous variant is likely pathogenic for TECTA-associated autosomal recessive hearing loss and seems to have arisen as a founder variant in this specific Latino subpopulation. This study demonstrates that synonymous variants need careful splicing assessment and support from additional testing methodologies to determine their clinical impact.


Assuntos
Surdez , Perda Auditiva , Humanos , Sítios de Splice de RNA , Splicing de RNA/genética , Perda Auditiva/genética , Surdez/genética , Éxons/genética , Proteínas da Matriz Extracelular/genética , Proteínas Ligadas por GPI/genética
7.
Int J Neonatal Screen ; 8(2)2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35735787

RESUMO

Recent advances in genomic sequencing technologies have expanded practitioners' utilization of genetic information in a timely and efficient manner for an accurate diagnosis. With an ever-increasing resource of genomic data from progress in the interpretation of genome sequences, clinicians face decisions about how and when genomic information should be presented to families, and at what potential expense. Presently, there is limited knowledge or experience in establishing the value of implementing genome sequencing into newborn screening. Herein we provide insight into the complexities and the burden and benefits of knowledge resulting from genome sequencing of newborns.

8.
J Mol Diagn ; 24(3): 205-218, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35041930

RESUMO

Clinical laboratories offering genome sequencing have the opportunity to return pharmacogenomic findings to patients, providing the added benefit of preemptive testing that could help inform medication selection or dosing throughout the lifespan. Implementation of pharmacogenomic reporting must address several challenges, including inherent limitations in short-read genome sequencing methods, gene and variant selection, standardization of genotype and phenotype nomenclature, and choice of guidelines and drugs to report. An automated pipeline, lmPGX, was developed as an end-to-end solution that produces two versions of a pharmacogenomic report, presenting either Clinical Pharmacogenetics Implementation Consortium or US Food and Drug Administration guidelines for 12 genes. The pipeline was validated for performance using reference samples and pharmacogenetic data from the Genetic Testing Reference Materials Coordination Program. To determine performance and limitations, lmPGX was compared with three additional publicly available pharmacogenomic pipelines. The lmPGX pipeline offers clinical laboratories an opportunity for seamless integration of pharmacogenomic results with genome reporting.


Assuntos
Farmacogenética , Testes Farmacogenômicos , Testes Genéticos , Genótipo , Humanos , Farmacogenética/métodos , Testes Farmacogenômicos/métodos , Fenótipo
9.
Thorax ; 77(5): 452-460, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34580195

RESUMO

INTRODUCTION: Asthma is a complex disease with heterogeneous expression/severity. There is growing interest in defining asthma endotypes consistently associated with different responses to therapy, focusing on type 2 inflammation (Th2) as a key pathological mechanism. Current asthma endotypes are defined primarily by clinical/laboratory criteria. Each endotype is likely characterised by distinct molecular mechanisms that identify optimal therapies. METHODS: We applied unsupervised (without a priori clinical criteria) principal component analysis on sputum airway cells RNA-sequencing transcriptomic data from 19 asthmatics from the Severe Asthma Research Program at baseline and 6-8 weeks follow-up after a 40 mg dose of intramuscular corticosteroids. We investigated principal components PC1, PC3 for association with 55 clinical variables. RESULTS: PC3 was associated with baseline Th2 clinical features including blood (rank-sum p=0.0082) and airway (rank-sum p=0.0024) eosinophilia, FEV1 change (Kendall tau-b R=-0.333 (-0.592 to -0.012)) and follow-up FEV1 albuterol response (Kendall tau-b R=0.392 (0.079 to 0.634)). PC1 with blood basophlia (rank-sum p=0.0191). The top 5% genes contributing to PC1, PC3 were enriched for distinct immune system/inflammation ontologies suggesting distinct subject-specific clusters of transcriptomic response to corticosteroids. PC3 association with FEV1 change was reproduced in silico in a comparable independent 14-subject (baseline, 8 weeks after daily inhaled corticosteroids (ICS)) airway epithelial cells microRNAome dataset. CONCLUSIONS: Transcriptomic PCs from this unsupervised methodology define molecular pharmacogenomic endotypes that may yield novel biology underlying different subject-specific responses to corticosteroid therapy in asthma, and optimal personalised asthma care. Top contributing genes to these PCs may suggest new therapeutic targets.


Assuntos
Asma , Eosinófilos , Corticosteroides/uso terapêutico , Asma/tratamento farmacológico , Asma/genética , Basófilos/patologia , Eosinófilos/patologia , Humanos , Inflamação , Pulmão , Escarro , Esteroides/uso terapêutico
10.
Genet Med ; 23(11): 2208-2212, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34230634

RESUMO

PURPOSE: The ClinGen Variant Curation Expert Panels (VCEPs) provide disease-specific rules for accurate variant interpretation. Using the hearing loss-specific American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) guidelines, the Hearing Loss VCEP (HL VCEP) illustrates the utility of expert specifications in variant interpretation. METHODS: A total of 157 variants across nine HL genes, previously submitted to ClinVar, were curated by the HL VCEP. The curation process involved collecting published and unpublished data for each variant by biocurators, followed by bimonthly meetings of an expert curation subgroup that reviewed all evidence and applied the HL-specific ACMG/AMP guidelines to reach a final classification. RESULTS: Before expert curation, 75% (117/157) of variants had single or multiple variants of uncertain significance (VUS) submissions (17/157) or had conflicting interpretations in ClinVar (100/157). After applying the HL-specific ACMG/AMP guidelines, 24% (4/17) of VUS and 69% (69/100) of discordant variants were resolved into benign (B), likely benign (LB), likely pathogenic (LP), or pathogenic (P). Overall, 70% (109/157) variants had unambiguous classifications (B, LB, LP, P). We quantify the contribution of the HL-specified ACMG/AMP codes to variant classification. CONCLUSION: Expert specification and application of the HL-specific ACMG/AMP guidelines effectively resolved discordant interpretations in ClinVar. This study highlights the utility of ClinGen VCEPs in supporting more consistent clinical variant interpretation.


Assuntos
Genoma Humano , Perda Auditiva , Humanos , Testes Genéticos , Variação Genética/genética , Perda Auditiva/diagnóstico , Perda Auditiva/genética
11.
Nat Genet ; 53(6): 787-793, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33958783

RESUMO

A key driver of patients' well-being and clinical trials for Parkinson's disease (PD) is the course that the disease takes over time (progression and prognosis). To assess how genetic variation influences the progression of PD over time to dementia, a major determinant for quality of life, we performed a longitudinal genome-wide survival study of 11.2 million variants in 3,821 patients with PD over 31,053 visits. We discover RIMS2 as a progression locus and confirm this in a replicate population (hazard ratio (HR) = 4.77, P = 2.78 × 10-11), identify suggestive evidence for TMEM108 (HR = 2.86, P = 2.09 × 10-8) and WWOX (HR = 2.12, P = 2.37 × 10-8) as progression loci, and confirm associations for GBA (HR = 1.93, P = 0.0002) and APOE (HR = 1.48, P = 0.001). Polygenic progression scores exhibit a substantial aggregate association with dementia risk, while polygenic susceptibility scores are not predictive. This study identifies a novel synaptic locus and polygenic score for cognitive disease progression in PD and proposes diverging genetic architectures of progression and susceptibility.


Assuntos
Cognição , Progressão da Doença , Loci Gênicos , Estudo de Associação Genômica Ampla , Herança Multifatorial/genética , Doença de Parkinson/genética , Doença de Parkinson/patologia , Sinapses/genética , Apolipoproteína E4/genética , Transtornos Cognitivos/genética , Predisposição Genética para Doença , Glucosilceramidase/genética , Humanos , Estudos Longitudinais , Mutação/genética , Doença de Parkinson/fisiopatologia , Modelos de Riscos Proporcionais , Fatores de Risco , Análise de Sobrevida
12.
Genes (Basel) ; 12(4)2021 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-33921607

RESUMO

Whole Exome Sequencing (WES) is a powerful approach for detecting sequence variations in the human genome. The aim of this study was to investigate the genetic defects in Jordanian patients with inherited retinal dystrophies (IRDs) using WES. WES was performed on proband patients' DNA samples from 55 Jordanian families. Sanger sequencing was used for validation and segregation analysis of the detected, potential disease-causing variants (DCVs). Thirty-five putatively causative variants (6 novel and 29 known) in 21 IRD-associated genes were identified in 71% of probands (39 of the 55 families). Three families showed phenotypes different from the typically reported clinical findings associated with the causative genes. To our knowledge, this is the largest genetic analysis of IRDs in the Jordanian population to date. Our study also confirms that WES is a powerful tool for the molecular diagnosis of IRDs in large patient cohorts.


Assuntos
Exoma , Marcadores Genéticos , Predisposição Genética para Doença , Mutação , Distrofias Retinianas/genética , Distrofias Retinianas/patologia , Adolescente , Adulto , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Estudos de Associação Genética , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Sequenciamento do Exoma , Adulto Jovem
13.
J Neurosci ; 41(20): 4378-4391, 2021 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-33824189

RESUMO

Transmembrane channel-like protein isoform 1 (TMC1) is a major component of the mechano-electrical transducer (MET) channel in cochlear hair cells and is subject to numerous mutations causing deafness. We report a new dominant human deafness mutation, TMC1 p.T422K, and have characterized the homologous mouse mutant, Tmc1 p.T416K, which caused deafness and outer hair cell (OHC) loss by the fourth postnatal week. MET channels showed decreased Ca2+ permeability and resting open probability, but no change in single-channel conductance or expression. Three adjacent deafness mutations are TMC1 p.L416R, p.G417R, and p.M418K, the last homologous to the mouse Beethoven that exhibits similar channel effects. All substitute a positive for a neutral residue, which could produce charge screening in the channel pore or influence binding of an accessory subunit. Channel properties were compared in mice of both sexes between dominant (Tmc1 p.T416K, Tmc1 p.D569N) and recessive (Tmc1 p.W554L, Tmc1 p.D528N) mutations of residues near the putative pore of the channel. Tmc1 p.W554L and p.D569N exhibit reduced maximum current with no effect on single-channel conductance, implying a smaller number of channels transported to the stereociliary tips; this may stem from impaired TMC1 binding to LHFPL5. Tmc1 p.D528N, located in the pore's narrowest region, uniquely caused large reductions in MET channel conductance and block by dihydrostreptomycin (DHS). For Tmc1 p.T416K and Tmc1 p.D528N, transduction loss occurred between P15 and P20. We propose two mechanisms linking channel mutations and deafness: decreased Ca2+ permeability, common to all mutants, and decreased resting open probability in low Ca2+, confined to dominant mutations.SIGNIFICANCE STATEMENT Transmembrane channel-like protein isoform 1 (TMC1) is thought to be a major component of the mechanotransducer channel in auditory hair cells, but the protein organization and channel structure are still uncertain. We made four mouse lines harboring Tmc1 point mutations that alter channel properties, causing hair cell degeneration and deafness. These include a mouse homolog of a new human deafness mutation pT416K that decreased channel Ca2+ permeability by introducing a positively-charged amino acid in the putative pore. All mutations are consistent with the channel structure predicted from modeling, but only one, p.D528N near the external face of the pore, substantially reduced channel conductance and Ca2+ permeability and virtually abolished block by dihydrostreptomycin (DHS), strongly endorsing its siting within the pore.


Assuntos
Surdez/genética , Surdez/metabolismo , Células Ciliadas Auditivas/metabolismo , Mecanotransdução Celular/genética , Proteínas de Membrana/genética , Adolescente , Adulto , Animais , Criança , Surdez/patologia , Feminino , Células Ciliadas Auditivas/patologia , Humanos , Masculino , Camundongos , Camundongos Mutantes , Pessoa de Meia-Idade , Linhagem , Mutação Puntual
14.
J Mol Diagn ; 23(6): 671-682, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33872788

RESUMO

When sequencing small RNA libraries derived from whole blood, the most abundant microRNAs (miRs) detected are often miR-486-5p, miR-451a, and miR-92a-3p. These highly expressed erythropoietic miRs are released into the sample from red blood cell hemolysis. Next-generation sequencing of these unwanted miRs leads to a waste in sequencing cost and diminished detection of lowly expressed miRNAs, including many potential miRNA biomarkers. Previous work has developed a method to reduce targeted miRNAs using oligonucleotides that bind their target miRNA and prevent its ligation during library construction, although the extent to which oligonucleotides can be multiplexed and their effect on larger cohorts has not been thoroughly explored. We present a method for suppressing detection of three highly abundant heme miRs in a single multiplexed blocking oligonucleotide reaction. In a small paired-sample pilot (n = 8) and a large cohort of samples (n = 901), multiplexed oligos reduced detection of their target miRNAs by approximately 70%, allowing for an approximately 10-fold increase in reads mapping to nonheme miRs and increased detection of very lowly expressed miRs, with minimal off-target effects. By removing all three highly expressed erythropoietic miRNAs from next-generational sequencing libraries, this commercially available multiplexed blocking oligonucleotide method allows for greater detection of lowly expressed biomarkers, improving the efficacy, cost-efficiency, and sensitivity of biomarker studies and diagnostic tests.


Assuntos
Hemólise/genética , MicroRNAs/genética , Oligonucleotídeos/farmacologia , RNA/sangue , Adulto , Estudos de Coortes , Humanos
15.
Hum Mutat ; 42(4): 373-377, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33492714

RESUMO

Bi-allelic loss-of-function variants of OTOA are a well-known cause of moderate-to-severe hearing loss. Whereas non-allelic homologous recombination-mediated deletions of the gene are well known, gene conversions to pseudogene OTOAP1 have been reported in the literature but never fully described nor their pathogenicity assessed. Here, we report two unrelated patients with moderate hearing-loss, who were compound heterozygotes for a converted allele and a deletion of OTOA. The conversions were initially detected through sequencing depths anomalies at the OTOA locus after exome sequencing, then confirmed with long range polymerase chain reactions. Both conversions lead to loss-of-function by introducing a premature stop codon in exon 22 (p.Glu787*). Using genomic alignments and long read nanopore sequencing, we found that the two probands carry stretches of converted DNA of widely different lengths (at least 9 kbp and around 900 bp, respectively).


Assuntos
Surdez , Proteínas Ligadas por GPI , Perda Auditiva , Alelos , Surdez/genética , Proteínas Ligadas por GPI/genética , Conversão Gênica , Perda Auditiva/genética , Humanos , Linhagem , Sequenciamento do Exoma
16.
Eur J Hum Genet ; 29(6): 988-997, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33398081

RESUMO

Nonsyndromic hearing loss is genetically heterogeneous. Despite comprehensive genetic testing, many cases remain unsolved because the clinical significance of identified variants is uncertain or because biallelic pathogenic variants are not identified for presumed autosomal recessive cases. Common synonymous variants are often disregarded. Determining the pathogenicity of synonymous variants may improve genetic diagnosis. We report a synonymous variant c.9861 C > T/p.(Gly3287=) in MYO15A in homozygosity or compound heterozygosity with another pathogenic or likely pathogenic MYO15A variant in 10 unrelated families with nonsyndromic sensorineural hearing loss. Biallelic variants in MYO15A were identified in 21 affected and were absent in 22 unaffected siblings. A mini-gene assay confirms that the synonymous variant leads to abnormal splicing. The variant is enriched in the Ashkenazi Jewish population. Individuals carrying biallelic variants involving c.9861 C > T often exhibit progressive post-lingual hearing loss distinct from the congenital profound deafness typically associated with biallelic loss-of-function MYO15A variants. This study establishes the pathogenicity of the c.9861 C > T variant in MYO15A and expands the phenotypic spectrum of MYO15A-related hearing loss. Our work also highlights the importance of multicenter collaboration and data sharing to establish the pathogenicity of a relatively common synonymous variant for improved diagnosis and management of hearing loss.


Assuntos
Frequência do Gene , Perda Auditiva/genética , Miosinas/genética , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Genes Recessivos , Perda Auditiva/etnologia , Perda Auditiva/patologia , Humanos , Lactente , Judeus/genética , Masculino , Mutação , Linhagem , Splicing de RNA
17.
Front Cell Neurosci ; 14: 585669, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33281559

RESUMO

Background: Hereditary hearing loss is a disorder with high genetic and allelic heterogeneity. Diagnostic screening of candidate genes commonly yields novel variants of unknown clinical significance. TBC1D24 is a pleiotropic gene associated with recessive DOORS syndrome, epileptic encephalopathy, myoclonic epilepsy, and both recessive and dominant hearing impairment. Genotype-phenotype correlations have not been established to date but could facilitate diagnostic variant assessment and elucidation of pathomechanisms. Methods and Results: Whole-exome and gene panel screening identified a novel (c.919A>C; p.Asn307His) causative variant in TBC1D24 in two unrelated Caucasian families with Autosomal dominant (AD) nonsyndromic late-onset hearing loss. Protein modeling on the Drosophila TBC1D24 ortholog Skywalker crystal structure showed close interhelix proximity (6.8Å) between the highly conserved residue p.Asn307 in α18 and the position of the single known pathogenic dominant variation (p.Ser178Leu) in α11 that causes a form of deafness with similar clinical characteristics. Conclusion: Genetic variants affecting two polar hydrophilic residues in neighboring helices of TBC1D24 cause AD nonsyndromic late-onset hearing loss. The spatial proximity of the affected residues suggests the first genotype-phenotype association in TBC1D24-related disorders. Three conserved residues in α18 contribute to the formation of a functionally relevant cationic phosphoinositide binding pocket that regulates synaptic vesicle trafficking which may be involved in the molecular mechanism of disease.

18.
Mol Vis ; 26: 445-458, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32587456

RESUMO

Purpose: The aim of this study is to identify disease-causing variants in five consanguineous Jordanian families with a history of autosomal recessive retinitis pigmentosa (RP), and to investigate the clinical variability across the affected individuals. Methods: Exome sequencing (ES) and ophthalmic examinations were performed to classify the underlying RP-causative variants and their pathogenic consequences. The candidate variants in the affected and unaffected family members underwent segregation analyses with Sanger sequencing. Results: We described four variants in the RP1 and RLBP1 genes as disease-causing across the five families, including novel (c.398delC; p.Pro133GlnfsTer126) and recurrent (c.79delA; p.Thr27ProfsTer26) variants in RLBP1 and two previously reported variants in RP1 ((c.1126C>T; p.Arg376Ter) and (c.607G>A; p.Gly203Arg)). The consequent clinical manifestations were thoroughly investigated using a battery of ophthalmic tests, including electroretinography (ERG), optical coherence tomography (OCT), visual acuity (VA), and fundus examination. The phenotypes indicated clinical heterogeneity, typical RP for variants in RP1, and retinitis punctata albescens (RPA) for variants in RLBP1. Conclusions: This study extends the pathogenic variant spectrum for the RP1 and RLBP1 genes. The study also revealed the consequent clinical progression, severity, and presentation of RP. Furthermore, we confirm that ES is an efficient molecular diagnostic approach for RP.


Assuntos
Proteínas de Transporte/genética , Proteínas Associadas aos Microtúbulos/genética , Retinose Pigmentar/diagnóstico , Retinose Pigmentar/genética , Adulto , Consanguinidade , Análise Mutacional de DNA , Eletrorretinografia , Família , Feminino , Fundo de Olho , Predisposição Genética para Doença , Genótipo , Humanos , Jordânia , Masculino , Pessoa de Meia-Idade , Mutação , Linhagem , Fenótipo , Retinose Pigmentar/diagnóstico por imagem , Retinose Pigmentar/fisiopatologia , Tomografia de Coerência Óptica , Acuidade Visual , Sequenciamento do Exoma
19.
JAMA Netw Open ; 3(4): e203959, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32347951

RESUMO

Importance: Pathogenic DNA variants associated with familial hypercholesterolemia, hereditary breast and ovarian cancer syndrome, and Lynch syndrome are widely recognized as clinically important and actionable when identified, leading some clinicians to recommend population-wide genomic screening. Objectives: To assess the prevalence and clinical importance of pathogenic or likely pathogenic variants associated with each of 3 genomic conditions (familial hypercholesterolemia, hereditary breast and ovarian cancer syndrome, and Lynch syndrome) within the context of contemporary clinical care. Design, Setting, and Participants: This cohort study used gene-sequencing data from 49 738 participants in the UK Biobank who were recruited from 22 sites across the UK between March 21, 2006, and October 1, 2010. Inpatient hospital data date back to 1977; cancer registry data, to 1957; and death registry data, to 2006. Statistical analysis was performed from July 22, 2019, to November 15, 2019. Exposures: Pathogenic or likely pathogenic DNA variants classified by a clinical laboratory geneticist. Main Outcomes and Measures: Composite end point specific to each genomic condition based on atherosclerotic cardiovascular disease events for familial hypercholesterolemia, breast or ovarian cancer for hereditary breast and ovarian cancer syndrome, and colorectal or uterine cancer for Lynch syndrome. Results: Among 49 738 participants (mean [SD] age, 57 [8] years; 27 144 female [55%]), 441 (0.9%) harbored a pathogenic or likely pathogenic variant associated with any of 3 genomic conditions, including 131 (0.3%) for familial hypercholesterolemia, 235 (0.5%) for hereditary breast and ovarian cancer syndrome, and 76 (0.2%) for Lynch syndrome. Presence of these variants was associated with increased risk of disease: for familial hypercholesterolemia, 28 of 131 carriers (21.4%) vs 4663 of 49 607 noncarriers (9.4%) developed atherosclerotic cardiovascular disease; for hereditary breast and ovarian cancer syndrome, 32 of 116 female carriers (27.6%) vs 2080 of 27 028 female noncarriers (7.7%) developed associated cancers; and for Lynch syndrome, 17 of 76 carriers (22.4%) vs 929 of 49 662 noncarriers (1.9%) developed colorectal or uterine cancer. The predicted probability of disease at age 75 years despite contemporary clinical care was 45.3% for carriers of familial hypercholesterolemia, 41.1% for hereditary breast and ovarian cancer syndrome, and 38.3% for Lynch syndrome. Across the 3 conditions, 39.7% (175 of 441) of the carriers reported a family history of disease vs 23.2% (34 517 of 148 772) of noncarriers. Conclusions and Relevance: The findings suggest that approximately 1% of the middle-aged adult population in the UK Biobank harbored a pathogenic variant associated with any of 3 genomic conditions. These variants were associated with an increased risk of disease despite contemporary clinical care and were not reliably detected by family history.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/genética , Predisposição Genética para Doença/epidemiologia , Síndrome Hereditária de Câncer de Mama e Ovário/genética , Hiperlipoproteinemia Tipo II/genética , Idoso , Estudos de Coortes , Feminino , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Modelos de Riscos Proporcionais , Reino Unido/epidemiologia , Sequenciamento do Exoma
20.
Sci Rep ; 10(1): 4552, 2020 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-32165660

RESUMO

Small RNA-Seq is a common means to interrogate the small RNA'ome or the full spectrum of small RNAs (<200 nucleotide length) of a biological system. A pivotal problem in NGS based small RNA analysis is identifying and quantifying the small RNA'ome constituent components. For example, small RNAs in the circulatory system (circulating RNAs) are potential disease biomarkers and their function is being actively investigated. Most existing NGS data analysis tools focus on the microRNA component and a few other small RNA types like piRNA, snRNA and snoRNA. A comprehensive platform is needed to interrogate the full small RNA'ome, a prerequisite for down-stream data analysis. We present COMPSRA, a comprehensive modular stand-alone platform for identifying and quantifying small RNAs from small RNA sequencing data. COMPSRA contains prebuilt customizable standard RNA databases and sequence processing tools to enable turnkey basic small RNA analysis. We evaluated COMPSRA against comparable existing tools on small RNA sequencing data set from serum samples of 12 healthy human controls, and COMPSRA identified a greater diversity and abundance of small RNA molecules. COMPSRA is modular, stand-alone and integrates multiple customizable RNA databases and sequence processing tool and is distributed under the GNU General Public License free to non-commercial registered users at https://github.com/cougarlj/COMPSRA.


Assuntos
Biologia Computacional/métodos , Pequeno RNA não Traduzido/sangue , Análise de Sequência de RNA/métodos , Voluntários Saudáveis , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Internet , Software
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