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1.
Am J Hum Genet ; 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38843839

RESUMEN

There is mounting evidence of the value of clinical genome sequencing (cGS) in individuals with suspected rare genetic disease (RGD), but cGS performance and impact on clinical care in a diverse population drawn from both high-income countries (HICs) and low- and middle-income countries (LMICs) has not been investigated. The iHope program, a philanthropic cGS initiative, established a network of 24 clinical sites in eight countries through which it provided cGS to individuals with signs or symptoms of an RGD and constrained access to molecular testing. A total of 1,004 individuals (median age, 6.5 years; 53.5% male) with diverse ancestral backgrounds (51.8% non-majority European) were assessed from June 2016 to September 2021. The diagnostic yield of cGS was 41.4% (416/1,004), with individuals from LMIC sites 1.7 times more likely to receive a positive test result compared to HIC sites (LMIC 56.5% [195/345] vs. HIC 33.5% [221/659], OR 2.6, 95% CI 1.9-3.4, p < 0.0001). A change in diagnostic evaluation occurred in 76.9% (514/668) of individuals. Change of management, inclusive of specialty referrals, imaging and testing, therapeutic interventions, and palliative care, was reported in 41.4% (285/694) of individuals, which increased to 69.2% (480/694) when genetic counseling and avoidance of additional testing were also included. Individuals from LMIC sites were as likely as their HIC counterparts to experience a change in diagnostic evaluation (OR 6.1, 95% CI 1.1-∞, p = 0.05) and change of management (OR 0.9, 95% CI 0.5-1.3, p = 0.49). Increased access to genomic testing may support diagnostic equity and the reduction of global health care disparities.

2.
Nat Microbiol ; 9(5): 1382-1392, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38649410

RESUMEN

RNA viruses, like SARS-CoV-2, depend on their RNA-dependent RNA polymerases (RdRp) for replication, which is error prone. Monitoring replication errors is crucial for understanding the virus's evolution. Current methods lack the precision to detect rare de novo RNA mutations, particularly in low-input samples such as those from patients. Here we introduce a targeted accurate RNA consensus sequencing method (tARC-seq) to accurately determine the mutation frequency and types in SARS-CoV-2, both in cell culture and clinical samples. Our findings show an average of 2.68 × 10-5 de novo errors per cycle with a C > T bias that cannot be solely attributed to APOBEC editing. We identified hotspots and cold spots throughout the genome, correlating with high or low GC content, and pinpointed transcription regulatory sites as regions more susceptible to errors. tARC-seq captured template switching events including insertions, deletions and complex mutations. These insights shed light on the genetic diversity generation and evolutionary dynamics of SARS-CoV-2.


Asunto(s)
COVID-19 , Genoma Viral , Mutación , ARN Viral , SARS-CoV-2 , Replicación Viral , SARS-CoV-2/genética , Humanos , Replicación Viral/genética , COVID-19/virología , Genoma Viral/genética , ARN Viral/genética , Análisis de Secuencia de ARN/métodos , Evolución Molecular , Tasa de Mutación
3.
J Pediatr Genet ; 13(1): 29-34, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38567173

RESUMEN

FOXP1 encodes a transcription factor involved in tissue regulation and cell-type-specific functions. Haploinsufficiency of FOXP1 is associated with a neurodevelopmental disorder: autosomal dominant mental retardation with language impairment with or without autistic features. More recently, heterozygous FOXP1 variants have also been shown to cause a variety of structural birth defects including central nervous system (CNS) anomalies, congenital heart defects, congenital anomalies of the kidney and urinary tract, cryptorchidism, and hypospadias. In this report, we present a previously unpublished case of an individual with congenital diaphragmatic hernia (CDH) who carries an approximately 3.8 Mb deletion. Based on this deletion, and deletions previously reported in two other individuals with CDH, we define a CDH critical region on chromosome 3p13 that includes FOXP1 and four other protein-coding genes. We also provide detailed clinical descriptions of two previously reported individuals with CDH who carry de novo, pathogenic variants in FOXP1 that are predicted to trigger nonsense-mediated mRNA decay. A subset of individuals with putatively deleterious FOXP4 variants has also been shown to develop CDH. Since FOXP proteins function as homo- or heterodimers and the homologs of FOXP1 and FOXP4 are expressed at the same time points in the embryonic mouse diaphragm, they may function together as a dimer, or in parallel as homodimers, to regulate gene expression during diaphragm development. Not all individuals with heterozygous, loss-of-function changes in FOXP1 develop CDH. Hence, we conclude that FOXP1 acts as a susceptibility factor that contributes to the development of CDH in conjunction with other genetic, epigenetic, environmental, and/or stochastic factors.

4.
Invest Ophthalmol Vis Sci ; 65(3): 25, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38502138

RESUMEN

Purpose: A molecular diagnosis is only made in a subset of individuals with nonisolated microphthalmia, anophthalmia, and coloboma (MAC). This may be due to underutilization of clinical (whole) exome sequencing (cES) and an incomplete understanding of the genes that cause MAC. The purpose of this study is to determine the efficacy of cES in cases of nonisolated MAC and to identify new MAC phenotypic expansions. Methods: We determined the efficacy of cES in 189 individuals with nonisolated MAC. We then used cES data, a validated machine learning algorithm, and previously published expression data, case reports, and animal models to determine which candidate genes were most likely to contribute to the development of MAC. Results: We found the efficacy of cES in nonisolated MAC to be between 32.3% (61/189) and 48.1% (91/189). Most genes affected in our cohort were not among genes currently screened in clinically available ophthalmologic gene panels. A subset of the genes implicated in our cohort had not been clearly associated with MAC. Our analyses revealed sufficient evidence to support low-penetrance MAC phenotypic expansions involving nine of these human disease genes. Conclusions: We conclude that cES is an effective means of identifying a molecular diagnosis in individuals with nonisolated MAC and may identify putatively damaging variants that would be missed if only a clinically available ophthalmologic gene panel was obtained. Our data also suggest that deleterious variants in BRCA2, BRIP1, KAT6A, KAT6B, NSF, RAC1, SMARCA4, SMC1A, and TUBA1A can contribute to the development of MAC.


Asunto(s)
Anoftalmos , Coloboma , Microftalmía , Animales , Humanos , Anoftalmos/diagnóstico , Anoftalmos/genética , Coloboma/diagnóstico , Coloboma/genética , Secuenciación del Exoma , Microftalmía/diagnóstico , Microftalmía/genética , Algoritmos , ADN Helicasas , Proteínas Nucleares , Factores de Transcripción/genética , Histona Acetiltransferasas
5.
Eur J Hum Genet ; 31(12): 1430-1439, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37673932

RESUMEN

Anomalous pulmonary venous return (APVR) frequently occurs with other congenital heart defects (CHDs) or extra-cardiac anomalies. While some genetic causes have been identified, the optimal approach to genetic testing in individuals with APVR remains uncertain, and the etiology of most cases of APVR is unclear. Here, we analyzed molecular data from 49 individuals to determine the diagnostic yield of clinical exome sequencing (ES) for non-isolated APVR. A definitive or probable diagnosis was made for 8 of those individuals yielding a diagnostic efficacy rate of 16.3%. We then analyzed molecular data from 62 individuals with APVR accrued from three databases to identify novel APVR genes. Based on data from this analysis, published case reports, mouse models, and/or similarity to known APVR genes as revealed by a machine learning algorithm, we identified 3 genes-EFTUD2, NAA15, and NKX2-1-for which there is sufficient evidence to support phenotypic expansion to include APVR. We also provide evidence that 3 recurrent copy number variants contribute to the development of APVR: proximal 1q21.1 microdeletions involving RBM8A and PDZK1, recurrent BP1-BP2 15q11.2 deletions, and central 22q11.2 deletions involving CRKL. Our results suggest that ES and chromosomal microarray analysis (or genome sequencing) should be considered for individuals with non-isolated APVR for whom a genetic etiology has not been identified, and that genetic testing to identify an independent genetic etiology of APVR is not warranted in individuals with EFTUD2-, NAA15-, and NKX2-1-related disorders.


Asunto(s)
Anomalías Múltiples , Cardiopatías Congénitas , Síndrome de Cimitarra , Animales , Ratones , Síndrome de Cimitarra/genética , Secuenciación del Exoma , Anomalías Múltiples/genética , Deleción Cromosómica , Pruebas Genéticas , Cardiopatías Congénitas/diagnóstico , Cardiopatías Congénitas/genética , Proteínas de Unión al ARN/genética
6.
iScience ; 26(9): 107596, 2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37664586

RESUMEN

Recent studies suggest that infection reprograms hematopoietic stem and progenitor cells (HSPCs) to enhance innate immune responses upon secondary infectious challenge, a process called "trained immunity." However, the specificity and cell types responsible for this response remain poorly defined. We established a model of trained immunity in mice in response to Mycobacterium avium infection. scRNA-seq analysis revealed that HSPCs activate interferon gamma-response genes heterogeneously upon primary challenge, while rare cell populations expand. Macrophages derived from trained HSPCs demonstrated enhanced bacterial killing and metabolism, and a single dose of recombinant interferon gamma exposure was sufficient to induce similar training. Mice transplanted with influenza-trained HSPCs displayed enhanced immunity against M. avium challenge and vice versa, demonstrating cross protection against antigenically distinct pathogens. Together, these results indicate that heterogeneous responses to infection by HSPCs can lead to long-term production of bone marrow derived macrophages with enhanced function and confer cross-protection against alternative pathogens.

7.
EMBO Rep ; 24(10): e55043, 2023 10 09.
Artículo en Inglés | MEDLINE | ID: mdl-37551717

RESUMEN

The cardiac endothelium influences ventricular chamber development by coordinating trabeculation and compaction. However, the endothelial-specific molecular mechanisms mediating this coordination are not fully understood. Here, we identify the Sox7 transcription factor as a critical cue instructing cardiac endothelium identity during ventricular chamber development. Endothelial-specific loss of Sox7 function in mice results in cardiac ventricular defects similar to non-compaction cardiomyopathy, with a change in the proportions of trabecular and compact cardiomyocytes in the mutant hearts. This phenotype is paralleled by abnormal coronary artery formation. Loss of Sox7 function disrupts the transcriptional regulation of the Notch pathway and connexins 37 and 40, which govern coronary arterial specification. Upon Sox7 endothelial-specific deletion, single-nuclei transcriptomics analysis identifies the depletion of a subset of Sox9/Gpc3-positive endocardial progenitor cells and an increase in erythro-myeloid cell lineages. Fate mapping analysis reveals that a subset of Sox7-null endothelial cells transdifferentiate into hematopoietic but not cardiomyocyte lineages. Our findings determine that Sox7 maintains cardiac endothelial cell identity, which is crucial to the cellular cross-talk that drives ventricular compaction and coronary artery development.


Asunto(s)
Vasos Coronarios , Células Endoteliales , Animales , Ratones , Vasos Coronarios/metabolismo , Células Endoteliales/metabolismo , Miocitos Cardíacos/metabolismo , Regulación de la Expresión Génica , Endotelio/metabolismo , Factores de Transcripción SOXF/genética , Factores de Transcripción SOXF/metabolismo
8.
Genet Med ; 25(10): 100916, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37334785

RESUMEN

PURPOSE: Genome sequencing (GS) may shorten the diagnostic odyssey for patients, but clinical experience with this assay in nonresearch settings remains limited. Texas Children's Hospital began offering GS as a clinical test to admitted patients in 2020, providing an opportunity to study GS utilization, possibilities for test optimization, and testing outcomes. METHODS: We retrospectively reviewed GS orders for admitted patients for a nearly 3-year period from March 2020 through December 2022. We gathered anonymized clinical data from the electronic health record to answer the study questions. RESULTS: The diagnostic yield over 97 admitted patients was 35%. The majority of GS clinical indications were neurologic or metabolic (61%) and most patients were in intensive care (58%). Tests were often characterized as candidates for intervention/improvement (56%), frequently because of redundancy with prior testing. Patients receiving GS without prior exome sequencing (ES) had higher diagnostic rates (45%) than the cohort as a whole. In 2 cases, GS revealed a molecular diagnosis that is unlikely to be detected by ES. CONCLUSION: The performance of GS in clinical settings likely justifies its use as a first-line diagnostic test, but the incremental benefit for patients with prior ES may be limited.


Asunto(s)
Pruebas Genéticas , Hospitales , Humanos , Niño , Estudios Retrospectivos , Secuenciación del Exoma , Mapeo Cromosómico
9.
Eur J Hum Genet ; 31(3): 296-303, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36474027

RESUMEN

Evidence suggests that genetic factors contribute to the development of anorectal malformations (ARMs). However, the etiology of the majority of ARMs cases remains unclear. Exome sequencing (ES) may be underutilized in the diagnostic workup of ARMs due to uncertainty regarding its diagnostic yield. In a clinical database of ~17,000 individuals referred for ES, we identified 130 individuals with syndromic ARMs. A definitive or probable diagnosis was made in 45 of these individuals for a diagnostic yield of 34.6% (45/130). The molecular diagnostic yield of individuals who initially met criteria for VACTERL association was lower than those who did not (26.8% vs 44.1%; p = 0.0437), suggesting that non-genetic factors may play an important role in this subset of syndromic ARM cases. Within this cohort, we identified two individuals who carried de novo pathogenic frameshift variants in ADNP, two individuals who were homozygous for pathogenic variants in BBS1, and single individuals who carried pathogenic or likely pathogenic variants in CREBBP, EP300, FANCC, KDM6A, SETD2, and SMARCA4. The association of these genes with ARMs was supported by previously published cases, and their similarity to known ARM genes as demonstrated using a machine learning algorithm. These data suggest that ES should be considered for all individuals with syndromic ARMs in whom a molecular diagnosis has not been made, and that ARMs represent a low penetrance phenotype associated with Helsmoortel-van der Aa syndrome, Bardet-Biedl syndrome 1, Rubinstein-Taybi syndromes 1 and 2, Fanconi anemia group C, Kabuki syndrome 2, SETD2-related disorders, and Coffin-Siris syndrome 4.


Asunto(s)
Malformaciones Anorrectales , Síndrome de Rubinstein-Taybi , Humanos , Malformaciones Anorrectales/diagnóstico , Malformaciones Anorrectales/genética , Patología Molecular , Fenotipo , Mutación del Sistema de Lectura , Síndrome de Rubinstein-Taybi/genética , ADN Helicasas/genética , Proteínas Nucleares/genética , Factores de Transcripción/genética , Proteínas Asociadas a Microtúbulos/genética
10.
Genome Med ; 14(1): 113, 2022 09 30.
Artículo en Inglés | MEDLINE | ID: mdl-36180924

RESUMEN

BACKGROUND: In medical genetics, discovery and characterization of disease trait contributory genes and alleles depends on genetic reasoning, study design, and patient ascertainment; we suggest a segmental haploid genetics approach to enhance gene discovery and molecular diagnostics. METHODS: We constructed a genome-wide map for nonallelic homologous recombination (NAHR)-mediated recurrent genomic deletions and used this map to estimate population frequencies of NAHR deletions based on large-scale population cohorts and region-specific studies. We calculated recessive disease carrier burden using high-quality pathogenic or likely pathogenic variants from ClinVar and gnomAD. We developed a NIRD (NAHR deletion Impact to Recessive Disease) score for recessive disorders by quantifying the contribution of NAHR deletion to the overall allele load that enumerated all pairwise combinations of disease-causing alleles; we used a Punnett square approach based on an assumption of random mating. Literature mining was conducted to identify all reported patients with defects in a gene with a high NIRD score; meta-analysis was performed on these patients to estimate the representation of NAHR deletions in recessive traits from contemporary human genomics studies. Retrospective analyses of extant clinical exome sequencing (cES) were performed for novel rare recessive disease trait gene and allele discovery from individuals with NAHR deletions. RESULTS: We present novel genomic insights regarding the genome-wide impact of NAHR recurrent segmental variants on recessive disease burden; we demonstrate the utility of NAHR recurrent deletions to enhance discovery in the challenging context of autosomal recessive (AR) traits and biallelic variation. Computational results demonstrate new mutations mediated by NAHR, involving recurrent deletions at 30 genomic regions, likely drive recessive disease burden for over 74% of loci within these segmental deletions or at least 2% of loci genome-wide. Meta-analyses on 170 literature-reported patients implicate that NAHR deletions are depleted from the ascertained pool of AR trait alleles. Exome reanalysis of personal genomes from subjects harboring recurrent deletions uncovered new disease-contributing variants in genes including COX10, ERCC6, PRRT2, and OTUD7A. CONCLUSIONS: Our results demonstrate that genomic sequencing of personal genomes with NAHR deletions could dramatically improve allele and gene discovery and enhance clinical molecular diagnosis. Moreover, results suggest NAHR events could potentially enable human haploid genetic screens as an approach to experimental inquiry into disease biology.


Asunto(s)
Genómica , Enfermedades Raras , Secuencia de Bases , Recombinación Homóloga , Humanos , Enfermedades Raras/genética , Estudios Retrospectivos
11.
Am J Med Genet A ; 188(10): 2958-2968, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35904974

RESUMEN

Congenital diaphragmatic hernia (CDH) can occur in isolation or in conjunction with other birth defects (CDH+). A molecular etiology can only be identified in a subset of CDH cases. This is due, in part, to an incomplete understanding of the genes that contribute to diaphragm development. Here, we used clinical and molecular data from 36 individuals with CDH+ who are cataloged in the DECIPHER database to identify genes that may play a role in diaphragm development and to discover new phenotypic expansions. Among this group, we identified individuals who carried putatively deleterious sequence or copy number variants affecting CREBBP, SMARCA4, UBA2, and USP9X. The role of these genes in diaphragm development was supported by their expression in the developing mouse diaphragm, their similarity to known CDH genes using data from a previously published and validated machine learning algorithm, and/or the presence of CDH in other individuals with their associated genetic disorders. Our results demonstrate how data from DECIPHER, and other public databases, can be used to identify new phenotypic expansions and suggest that CREBBP, SMARCA4, UBA2, and USP9X play a role in diaphragm development.


Asunto(s)
Hernias Diafragmáticas Congénitas , Animales , Variaciones en el Número de Copia de ADN , Diafragma , Hernias Diafragmáticas Congénitas/genética , Ratones
12.
Neurol Genet ; 8(4): e200002, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35747619

RESUMEN

Background and Objectives: Genetic variants affect both Parkinson disease (PD) risk and manifestations. Although genetic information is of potential interest to patients and clinicians, genetic testing is rarely performed during routine PD clinical care. The goal of this study was to examine interest in comprehensive genetic testing among patients with PD and document reactions to possible findings from genome sequencing in 2 academic movement disorder clinics. Methods: In 203 subjects with PD (age = 63 years, 67% male), genome sequencing was performed and filtered using a custom panel, including 49 genes associated with PD, parkinsonism, or related disorders, as well as a 90-variant PD genetic risk score. Based on the results, 231 patients (age = 67 years, 63% male) were surveyed on interest in genetic testing and responses to vignettes covering (1) familial risk of PD (LRRK2); (2) risk of PD dementia (GBA); (3) PD genetic risk score; and (4) secondary, medically actionable variants (BRCA1). Results: Genome sequencing revealed a LRRK2 variant in 3% and a GBA risk variant in 10% of our clinical sample. The genetic risk score was normally distributed, identifying 41 subjects with a high risk of PD. Medically actionable findings were discovered in 2 subjects (1%). In our survey, the majority (82%) responded that they would share a LRRK2 variant with relatives. Most registered unchanged or increased interest in testing when confronted with a potential risk for dementia or medically actionable findings, and most (75%) expressed interest in learning their PD genetic risk score. Discussion: Our results highlight broad interest in comprehensive genetic testing among patients with PD and may facilitate integration of genome sequencing in clinical practice.

13.
J Med Genet ; 59(3): 270-278, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-33461977

RESUMEN

BACKGROUND: Congenital diaphragmatic hernia (CDH) is a life-threatening birth defect that often co-occurs with non-hernia-related anomalies (CDH+). While copy number variant (CNV) analysis is often employed as a diagnostic test for CDH+, clinical exome sequencing (ES) has not been universally adopted. METHODS: We analysed a clinical database of ~12 000 test results to determine the diagnostic yields of ES in CDH+ and to identify new phenotypic expansions. RESULTS: Among the 76 cases with an indication of CDH+, a molecular diagnosis was made in 28 cases for a diagnostic yield of 37% (28/76). A provisional diagnosis was made in seven other cases (9%; 7/76). Four individuals had a diagnosis of Kabuki syndrome caused by frameshift variants in KMT2D. Putatively deleterious variants in ALG12 and EP300 were each found in two individuals, supporting their role in CDH development. We also identified individuals with de novo pathogenic variants in FOXP1 and SMARCA4, and compound heterozygous pathogenic variants in BRCA2. The role of these genes in CDH development is supported by the expression of their mouse homologs in the developing diaphragm, their high CDH-specific pathogenicity scores generated using a previously validated algorithm for genome-scale knowledge synthesis and previously published case reports. CONCLUSION: We conclude that ES should be ordered in cases of CDH+ when a specific diagnosis is not suspected and CNV analyses are negative. Our results also provide evidence in favour of phenotypic expansions involving CDH for genes associated with ALG12-congenital disorder of glycosylation, Rubinstein-Taybi syndrome, Fanconi anaemia, Coffin-Siris syndrome and FOXP1-related disorders.


Asunto(s)
Hernias Diafragmáticas Congénitas , Animales , Variaciones en el Número de Copia de ADN/genética , ADN Helicasas/genética , Exoma/genética , Factores de Transcripción Forkhead/genética , Mutación del Sistema de Lectura , Hernias Diafragmáticas Congénitas/diagnóstico , Hernias Diafragmáticas Congénitas/genética , Humanos , Ratones , Proteínas Nucleares/genética , Proteínas Represoras/genética , Factores de Transcripción/genética , Secuenciación del Exoma
14.
Cancer Genet ; 258-259: 80-84, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34592632

RESUMEN

Escape from nonsense mediated mRNA decay (NMD-) can produce activated or inactivated gene products, and bias in rates of escape can identify functionally important genes in germline disease. We hypothesized that the same would be true of cancer genes, and tested for NMD- bias within The Cancer Genome Atlas pan-cancer somatic mutation dataset. We identify 29 genes that show significantly elevated or suppressed rates of NMD-. This novel approach to cancer gene discovery reveals genes not previously cataloged as potentially tumorigenic, and identifies many potential driver mutations in known cancer genes for functional characterization.


Asunto(s)
Biomarcadores de Tumor/genética , Codón sin Sentido , Genoma Humano , Neoplasias/patología , Degradación de ARNm Mediada por Codón sin Sentido , Fenotipo , Humanos , Neoplasias/genética , Pronóstico
15.
PLoS Comput Biol ; 16(12): e1008473, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33315858

RESUMEN

Changes in the composition of the microbiome over time are associated with myriad human illnesses. Unfortunately, the lack of analytic techniques has hindered researchers' ability to quantify the association between longitudinal microbial composition and time-to-event outcomes. Prior methodological work developed the joint model for longitudinal and time-to-event data to incorporate time-dependent biomarker covariates into the hazard regression approach to disease outcomes. The original implementation of this joint modeling approach employed a linear mixed effects model to represent the time-dependent covariates. However, when the distribution of the time-dependent covariate is non-Gaussian, as is the case with microbial abundances, researchers require different statistical methodology. We present a joint modeling framework that uses a negative binomial mixed effects model to determine longitudinal taxon abundances. We incorporate these modeled microbial abundances into a hazard function with a parameterization that not only accounts for the proportional nature of microbiome data, but also generates biologically interpretable results. Herein we demonstrate the performance improvements of our approach over existing alternatives via simulation as well as a previously published longitudinal dataset studying the microbiome during pregnancy. The results demonstrate that our joint modeling framework for longitudinal microbiome count data provides a powerful methodology to uncover associations between changes in microbial abundances over time and the onset of disease. This method offers the potential to equip researchers with a deeper understanding of the associations between longitudinal microbial composition changes and disease outcomes. This new approach could potentially lead to new diagnostic biomarkers or inform clinical interventions to help prevent or treat disease.


Asunto(s)
Enfermedad , Microbiota , Modelos Estadísticos , Modelos Teóricos , Biomarcadores/análisis , Femenino , Humanos , Estudios Longitudinales , Preeclampsia/microbiología , Embarazo , Prevotella/aislamiento & purificación , Prevotella/patogenicidad , Modelos de Riesgos Proporcionales , Programas Informáticos
16.
Neurol Genet ; 6(5): e498, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32802956

RESUMEN

OBJECTIVE: To determine how single nucleotide variants (SNVs) and copy number variants (CNVs) contribute to molecular diagnosis in familial Parkinson disease (PD), we integrated exome sequencing (ES) and genome-wide array-based comparative genomic hybridization (aCGH) and further probed CNV structure to reveal mutational mechanisms. METHODS: We performed ES on 110 subjects with PD and a positive family history; 99 subjects were also evaluated using genome-wide aCGH. We interrogated ES and aCGH data for pathogenic SNVs and CNVs at Mendelian PD gene loci. We confirmed SNVs via Sanger sequencing and further characterized CNVs with custom-designed high-density aCGH, droplet digital PCR, and breakpoint sequencing. RESULTS: Using ES, we discovered individuals with known pathogenic SNVs in GBA (p.Glu365Lys, p.Thr408Met, p.Asn409Ser, and p.Leu483Pro) and LRRK2 (p.Arg1441Gly and p.Gly2019Ser). Two subjects were each double heterozygotes for variants in GBA and LRRK2. Based on aCGH, we additionally discovered cases with an SNCA duplication and heterozygous intragenic GBA deletion. Five additional subjects harbored both SNVs (p.Asn52Metfs*29, p.Thr240Met, p.Pro437Leu, and p.Trp453*) and likely disrupting CNVs at the PRKN locus, consistent with compound heterozygosity. In nearly all cases, breakpoint sequencing revealed microhomology, a mutational signature consistent with CNV formation due to DNA replication errors. CONCLUSIONS: Integrated ES and aCGH yielded a genetic diagnosis in 19.3% of our familial PD cohort. Our analyses highlight potential mechanisms for SNCA and PRKN CNV formation, uncover multilocus pathogenic variation, and identify novel SNVs and CNVs for further investigation as potential PD risk alleles.

17.
Genet Med ; 22(11): 1768-1776, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32655138

RESUMEN

PURPOSE: The goal of this study was to assess the scale of low-level parental mosaicism in exome sequencing (ES) databases. METHODS: We analyzed approximately 2000 family trio ES data sets from the Baylor-Hopkins Center for Mendelian Genomics (BHCMG) and Baylor Genetics (BG). Among apparent de novo single-nucleotide variants identified in the affected probands, we selected rare unique variants with variant allele fraction (VAF) between 30% and 70% in the probands and lower than 10% in one of the parents. RESULTS: Of 102 candidate mosaic variants validated using amplicon-based next-generation sequencing, droplet digital polymerase chain reaction, or blocker displacement amplification, 27 (26.4%) were confirmed to be low- (VAF between 1% and 10%) or very low (VAF <1%) level mosaic. Detection precision in parental samples with two or more alternate reads was 63.6% (BHCMG) and 43.6% (BG). In nine investigated individuals, we observed variability of mosaic ratios among blood, saliva, fibroblast, buccal, hair, and urine samples. CONCLUSION: Our computational pipeline enables robust discrimination between true and false positive candidate mosaic variants and efficient detection of low-level mosaicism in ES samples. We confirm that the presence of two or more alternate reads in the parental sample is a reliable predictor of low-level parental somatic mosaicism.


Asunto(s)
Exoma , Mosaicismo , Exoma/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Padres , Secuenciación del Exoma
18.
PLoS Comput Biol ; 16(7): e1007504, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32692749

RESUMEN

NGS studies have uncovered an ever-growing catalog of human variation while leaving an enormous gap between observed variation and experimental characterization of variant function. High-throughput screens powered by NGS have greatly increased the rate of variant functionalization, but the development of comprehensive statistical methods to analyze screen data has lagged. In the massively parallel reporter assay (MPRA), short barcodes are counted by sequencing DNA libraries transfected into cells and the cell's output RNA in order to simultaneously measure the shifts in transcription induced by thousands of genetic variants. These counts present many statistical challenges, including overdispersion, depth dependence, and uncertain DNA concentrations. So far, the statistical methods used have been rudimentary, employing transformations on count level data and disregarding experimental and technical structure while failing to quantify uncertainty in the statistical model. We have developed an extensive framework for the analysis of NGS functionalization screens available as an R package called malacoda (available from github.com/andrewGhazi/malacoda). Our software implements a probabilistic, fully Bayesian model of screen data. The model uses the negative binomial distribution with gamma priors to model sequencing counts while accounting for effects from input library preparation and sequencing depth. The method leverages the high-throughput nature of the assay to estimate the priors empirically. External annotations such as ENCODE data or DeepSea predictions can also be incorporated to obtain more informative priors-a transformative capability for data integration. The package also includes quality control and utility functions, including automated barcode counting and visualization methods. To validate our method, we analyzed several datasets using malacoda and alternative MPRA analysis methods. These data include experiments from the literature, simulated assays, and primary MPRA data. We also used luciferase assays to experimentally validate several hits from our primary data, as well as variants for which the various methods disagree and variants detectable only with the aid of external annotations.


Asunto(s)
Biología Computacional/métodos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Modelos Estadísticos , Análisis de Secuencia de ADN/métodos , Programas Informáticos , Teorema de Bayes , Variación Genética/genética , Humanos
19.
Genet Med ; 22(10): 1633-1641, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32576985

RESUMEN

PURPOSE: Improved resolution of molecular diagnostic technologies enabled detection of smaller sized exonic level copy-number variants (CNVs). The contribution of CNVs to autosomal recessive (AR) conditions may be better recognized using a large clinical cohort. METHODS: We retrospectively investigated the CNVs' contribution to AR conditions in cases subjected to chromosomal microarray analysis (CMA, N = ~70,000) and/or clinical exome sequencing (ES, N = ~12,000) at Baylor Genetics; most had pediatric onset neurodevelopmental disorders. RESULTS: CNVs contributed to biallelic variations in 87 cases, including 81 singletons and three affected sibling pairs. Seventy cases had CNVs affecting both alleles, and 17 had a CNV and a single-nucleotide variant (SNV)/indel in trans. In total, 94.3% of AR-CNVs affected one gene; among these 41.4% were single-exon and 35.0% were multiexon partial-gene events. Sixty-nine percent of homozygous AR-CNVs were embedded in homozygous genomic intervals. Five cases had large deletions unmasking an SNV/indel on the intact allele for a recessive condition, resulting in multiple molecular diagnoses. CONCLUSIONS: AR-CNVs are often smaller in size, transmitted through generations, and underrecognized due to limitations in clinical CNV detection methods. Our findings from a large clinical cohort emphasized integrated CNV and SNV/indel analyses for precise clinical and molecular diagnosis especially in the context of genomic disorders.


Asunto(s)
Variaciones en el Número de Copia de ADN , Mutación INDEL , Niño , Variaciones en el Número de Copia de ADN/genética , Exones , Humanos , Estudios Retrospectivos , Secuenciación del Exoma
20.
J Allergy Clin Immunol ; 145(2): 518-527.e8, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31738994

RESUMEN

BACKGROUND: The role of the airway microbiome in the development of recurrent wheezing and asthma remains uncertain, particularly in the high-risk group of infants hospitalized for bronchiolitis. OBJECTIVE: We sought to examine the relation of the nasal microbiota at bronchiolitis-related hospitalization and 3 later points to the risk of recurrent wheezing by age 3 years. METHODS: In 17 US centers researchers collected clinical data and nasal swabs from infants hospitalized for bronchiolitis. Trained parents collected nasal swabs 3 weeks after hospitalization and, when healthy, during the summer and 1 year after hospitalization. We applied 16S rRNA gene sequencing to all nasal swabs. We used joint modeling to examine the relation of longitudinal nasal microbiota abundances to the risk of recurrent wheezing. RESULTS: Among 842 infants hospitalized for bronchiolitis, there was 88% follow-up at 3 years, and 31% had recurrent wheezing. The median age at enrollment was 3.2 months (interquartile range, 1.7-5.8 months). In joint modeling analyses adjusting for 16 covariates, including viral cause, a 10% increase in relative abundance of Moraxella or Streptococcus species 3 weeks after day 1 of hospitalization was associated with an increased risk of recurrent wheezing (hazard ratio [HR] of 1.38 and 95% high-density interval [HDI] of 1.11-1.85 and HR of 1.76 and 95% HDI of 1.13-3.19, respectively). Increased Streptococcus species abundance the summer after hospitalization was also associated with a greater risk of recurrent wheezing (HR, 1.76; 95% HDI, 1.15-3.27). CONCLUSIONS: Enrichment of Moraxella or Streptococcus species after bronchiolitis hospitalization was associated with recurrent wheezing by age 3 years, possibly providing new avenues to ameliorate the long-term respiratory outcomes of infants with severe bronchiolitis.


Asunto(s)
Bronquiolitis/complicaciones , Moraxella , Mucosa Nasal/microbiología , Ruidos Respiratorios , Streptococcus , Bronquiolitis/microbiología , Preescolar , Femenino , Humanos , Lactante , Estudios Longitudinales , Masculino , Ruidos Respiratorios/etiología
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