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1.
J Am Soc Nephrol ; 2020 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-31919107

RESUMO

BACKGROUND: Primary membranoproliferative GN, including complement 3 (C3) glomerulopathy, is a rare, untreatable kidney disease characterized by glomerular complement deposition. Complement gene mutations can cause familial C3 glomerulopathy, and studies have reported rare variants in complement genes in nonfamilial primary membranoproliferative GN. METHODS: We analyzed whole-genome sequence data from 165 primary membranoproliferative GN cases and 10,250 individuals without the condition (controls) as part of the National Institutes of Health Research BioResource-Rare Diseases Study. We examined copy number, rare, and common variants. RESULTS: Our analysis included 146 primary membranoproliferative GN cases and 6442 controls who were unrelated and of European ancestry. We observed no significant enrichment of rare variants in candidate genes (genes encoding components of the complement alternative pathway and other genes associated with the related disease atypical hemolytic uremic syndrome; 6.8% in cases versus 5.9% in controls) or exome-wide. However, a significant common variant locus was identified at 6p21.32 (rs35406322) (P=3.29×10-8; odds ratio [OR], 1.93; 95% confidence interval [95% CI], 1.53 to 2.44), overlapping the HLA locus. Imputation of HLA types mapped this signal to a haplotype incorporating DQA1*05:01, DQB1*02:01, and DRB1*03:01 (P=1.21×10-8; OR, 2.19; 95% CI, 1.66 to 2.89). This finding was replicated by analysis of HLA serotypes in 338 individuals with membranoproliferative GN and 15,614 individuals with nonimmune renal failure. CONCLUSIONS: We found that HLA type, but not rare complement gene variation, is associated with primary membranoproliferative GN. These findings challenge the paradigm of complement gene mutations typically causing primary membranoproliferative GN and implicate an underlying autoimmune mechanism in most cases.

2.
Hum Mutat ; 2019 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-31562665

RESUMO

The heterogeneous manifestations of MYH9-related disorder (MYH9-RD), characterized by macrothrombocytopenia, Döhle-like inclusion bodies in leukocytes, bleeding of variable severity with, in some cases, ear, eye, kidney, and liver involvement, make the diagnosis for these patients still challenging in clinical practice. We collected phenotypic data and analyzed the genetic variants in more than 3,000 patients with a bleeding or platelet disorder. Patients were enrolled in the BRIDGE-BPD and ThromboGenomics Projects and their samples processed by high throughput sequencing (HTS). We identified 50 patients with a rare variant in MYH9. All patients had macrothrombocytes and all except two had thrombocytopenia. Some degree of bleeding diathesis was reported in 41 of the 50 patients. Eleven patients presented hearing impairment, three renal failure and two elevated liver enzymes. Among the 28 rare variants identified in MYH9, 12 were novel. HTS was instrumental in diagnosing 23 patients (46%). Our results confirm the clinical heterogeneity of MYH9-RD and show that, in the presence of an unclassified platelet disorder with macrothrombocytes, MYH9-RD should always be considered. A HTS-based strategy is a reliable method to reach a conclusive diagnosis of MYH9-RD in clinical practice.

3.
Blood ; 134(23): 2070-2081, 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31217188

RESUMO

To identify novel causes of hereditary thrombocytopenia, we performed a genetic association analysis of whole-genome sequencing data from 13 037 individuals enrolled in the National Institute for Health Research (NIHR) BioResource, including 233 cases with isolated thrombocytopenia. We found an association between rare variants in the transcription factor-encoding gene IKZF5 and thrombocytopenia. We report 5 causal missense variants in or near IKZF5 zinc fingers, of which 2 occurred de novo and 3 co-segregated in 3 pedigrees. A canonical DNA-zinc finger binding model predicts that 3 of the variants alter DNA recognition. Expression studies showed that chromatin binding was disrupted in mutant compared with wild-type IKZF5, and electron microscopy revealed a reduced quantity of α granules in normally sized platelets. Proplatelet formation was reduced in megakaryocytes from 7 cases relative to 6 controls. Comparison of RNA-sequencing data from platelets, monocytes, neutrophils, and CD4+ T cells from 3 cases and 14 healthy controls showed 1194 differentially expressed genes in platelets but only 4 differentially expressed genes in each of the other blood cell types. In conclusion, IKZF5 is a novel transcriptional regulator of megakaryopoiesis and the eighth transcription factor associated with dominant thrombocytopenia in humans.

4.
JIMD Rep ; 47(1): 9-16, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31240161

RESUMO

Background: Brain monoamine vesicular transport disease is an infantile onset neurodevelopmental disorder caused by variants in SLC18A2, which codes for the vesicular monoamine transporter 2 (VMAT2) protein, involved in the transport of monoamines into synaptic vesicles and of serotonin into platelet dense granules. Case presentation: The presented case is of a child, born of healthy consanguineous parents, who exhibited hypotonia, mental disability, epilepsy, uncontrolled movements, and gastrointestinal problems. A trial treatment with L-DOPA proved unsuccessful and the exact neurological involvement could not be discerned due to normal metabolic and brain magnetic resonance imaging results.Platelet studies and whole genome sequencing were performed. At age 4, the child's platelets showed a mild aggregation and adenosine triphosphate secretion defect that could be explained by dysmorphic dense granules observed by electron microscopy. Interestingly, the dense granules were almost completely depleted of serotonin. A novel homozygous p.P316A missense variant in VMAT2 was detected in the patient and the consanguineous parents were found to be heterozygous for this variant. Although the presence of VMAT2 on platelet dense granules has been demonstrated before, this is the first report of defective platelet dense granule function related to absent serotonin storage in a patient with VMAT2 deficiency but without obvious clinical bleeding problems. Conclusions: This study illustrates the homology between serotonin metabolism in brain and platelets, suggesting that these blood cells can be model cells for some pathways relevant for neurological diseases. The literature on VMAT2 deficiency is reviewed.

5.
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.

6.
Genome Med ; 10(1): 95, 2018 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-30526634

RESUMO

BACKGROUND: Studies have shown that complex structural variants (cxSVs) contribute to human genomic variation and can cause Mendelian disease. We aimed to identify cxSVs relevant to Mendelian disease using short-read whole-genome sequencing (WGS), resolve the precise variant configuration and investigate possible mechanisms of cxSV formation. METHODS: We performed short-read WGS and analysis of breakpoint junctions to identify cxSVs in a cohort of 1324 undiagnosed rare disease patients. Long-read WGS and gene expression analysis were used to resolve one case. RESULTS: We identified three pathogenic cxSVs: a de novo duplication-inversion-inversion-deletion affecting ARID1B, a de novo deletion-inversion-duplication affecting HNRNPU and a homozygous deletion-inversion-deletion affecting CEP78. Additionally, a de novo duplication-inversion-duplication overlapping CDKL5 was resolved by long-read WGS demonstrating the presence of both a disrupted and an intact copy of CDKL5 on the same allele, and gene expression analysis showed both parental alleles of CDKL5 were expressed. Breakpoint analysis in all the cxSVs revealed both microhomology and longer repetitive elements. CONCLUSIONS: Our results corroborate that cxSVs cause Mendelian disease, and we recommend their consideration during clinical investigations. We show that resolution of breakpoints can be critical to interpret pathogenicity and present evidence of replication-based mechanisms in cxSV formation.


Assuntos
Genoma Humano , Variação Estrutural do Genoma , Proteínas de Ciclo Celular/genética , Proteínas de Ligação a DNA/genética , Feminino , Predisposição Genética para Doença , Ribonucleoproteínas Nucleares Heterogêneas Grupo U/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Mutação , Proteínas Serina-Treonina Quinases/genética , Análise de Sequência de DNA , Fatores de Transcrição/genética
7.
Am J Hum Genet ; 103(1): 3-18, 2018 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-29909963

RESUMO

Multiple primary tumors (MPTs) affect a substantial proportion of cancer survivors and can result from various causes, including inherited predisposition. Currently, germline genetic testing of MPT-affected individuals for variants in cancer-predisposition genes (CPGs) is mostly targeted by tumor type. We ascertained pre-assessed MPT individuals (with at least two primary tumors by age 60 years or at least three by 70 years) from genetics centers and performed whole-genome sequencing (WGS) on 460 individuals from 440 families. Despite previous negative genetic assessment and molecular investigations, pathogenic variants in moderate- and high-risk CPGs were detected in 67/440 (15.2%) probands. WGS detected variants that would not be (or were not) detected by targeted resequencing strategies, including low-frequency structural variants (6/440 [1.4%] probands). In most individuals with a germline variant assessed as pathogenic or likely pathogenic (P/LP), at least one of their tumor types was characteristic of variants in the relevant CPG. However, in 29 probands (42.2% of those with a P/LP variant), the tumor phenotype appeared discordant. The frequency of individuals with truncating or splice-site CPG variants and at least one discordant tumor type was significantly higher than in a control population (χ2 = 43.642; p ≤ 0.0001). 2/67 (3%) probands with P/LP variants had evidence of multiple inherited neoplasia allele syndrome (MINAS) with deleterious variants in two CPGs. Together with variant detection rates from a previous series of similarly ascertained MPT-affected individuals, the present results suggest that first-line comprehensive CPG analysis in an MPT cohort referred to clinical genetics services would detect a deleterious variant in about a third of individuals.


Assuntos
Predisposição Genética para Doença/genética , Variação Genética/genética , Neoplasias Primárias Múltiplas/genética , Adulto , Idoso , Biomarcadores Tumorais/genética , Feminino , Testes Genéticos/métodos , Mutação em Linhagem Germinativa/genética , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo
8.
J Allergy Clin Immunol ; 142(2): 630-646, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29391254

RESUMO

BACKGROUND: Roifman syndrome is a rare inherited disorder characterized by spondyloepiphyseal dysplasia, growth retardation, cognitive delay, hypogammaglobulinemia, and, in some patients, thrombocytopenia. Compound heterozygous variants in the small nuclear RNA gene RNU4ATAC, which is necessary for U12-type intron splicing, were identified recently as driving Roifman syndrome. OBJECTIVE: We studied 3 patients from 2 unrelated kindreds harboring compound heterozygous or homozygous stem II variants in RNU4ATAC to gain insight into the mechanisms behind this disorder. METHODS: We systematically profiled the immunologic and hematologic compartments of the 3 patients with Roifman syndrome and performed RNA sequencing to unravel important splicing defects in both cell lineages. RESULTS: The patients exhibited a dramatic reduction in B-cell numbers, with differentiation halted at the transitional B-cell stage. Despite abundant B-cell activating factor availability, development past this B-cell activating factor-dependent stage was crippled, with disturbed minor splicing of the critical mitogen-activated protein kinase 1 signaling component. In the hematologic compartment patients with Roifman syndrome demonstrated defects in megakaryocyte differentiation, with inadequate generation of proplatelets. Platelets from patients with Roifman syndrome were rounder, with increased tubulin and actin levels, and contained increased α-granule and dense granule markers. Significant minor intron retention in 354 megakaryocyte genes was observed, including DIAPH1 and HPS1, genes known to regulate platelet and dense granule formation, respectively. CONCLUSION: Together, our results provide novel molecular and cellular data toward understanding the immunologic and hematologic features of Roifman syndrome.


Assuntos
Linfócitos B/fisiologia , Plaquetas/fisiologia , Cardiomiopatias/genética , Síndromes de Imunodeficiência/genética , Megacariócitos/fisiologia , Retardo Mental Ligado ao Cromossomo X/genética , Proteína Quinase 1 Ativada por Mitógeno/genética , Osteocondrodisplasias/genética , Células Precursoras de Linfócitos B/fisiologia , RNA Nuclear Pequeno/genética , Doenças Retinianas/genética , Adolescente , Diferenciação Celular , Linhagem da Célula , Proliferação de Células , Células Cultivadas , Criança , Pré-Escolar , Humanos , Lactente , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Linhagem , Processamento de Proteína/genética , Transdução de Sinais/genética , Sequenciamento Completo do Exoma
10.
J Am Coll Cardiol ; 69(7): 823-836, 2017 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-28209224

RESUMO

BACKGROUND: Genome-wide association studies have so far identified 56 loci associated with risk of coronary artery disease (CAD). Many CAD loci show pleiotropy; that is, they are also associated with other diseases or traits. OBJECTIVES: This study sought to systematically test if genetic variants identified for non-CAD diseases/traits also associate with CAD and to undertake a comprehensive analysis of the extent of pleiotropy of all CAD loci. METHODS: In discovery analyses involving 42,335 CAD cases and 78,240 control subjects we tested the association of 29,383 common (minor allele frequency >5%) single nucleotide polymorphisms available on the exome array, which included a substantial proportion of known or suspected single nucleotide polymorphisms associated with common diseases or traits as of 2011. Suggestive association signals were replicated in an additional 30,533 cases and 42,530 control subjects. To evaluate pleiotropy, we tested CAD loci for association with cardiovascular risk factors (lipid traits, blood pressure phenotypes, body mass index, diabetes, and smoking behavior), as well as with other diseases/traits through interrogation of currently available genome-wide association study catalogs. RESULTS: We identified 6 new loci associated with CAD at genome-wide significance: on 2q37 (KCNJ13-GIGYF2), 6p21 (C2), 11p15 (MRVI1-CTR9), 12q13 (LRP1), 12q24 (SCARB1), and 16q13 (CETP). Risk allele frequencies ranged from 0.15 to 0.86, and odds ratio per copy of the risk allele ranged from 1.04 to 1.09. Of 62 new and known CAD loci, 24 (38.7%) showed statistical association with a traditional cardiovascular risk factor, with some showing multiple associations, and 29 (47%) showed associations at p < 1 × 10-4 with a range of other diseases/traits. CONCLUSIONS: We identified 6 loci associated with CAD at genome-wide significance. Several CAD loci show substantial pleiotropy, which may help us understand the mechanisms by which these loci affect CAD risk.


Assuntos
Doença da Artéria Coronariana/genética , Loci Gênicos , Pleiotropia Genética , Estudos de Casos e Controles , Doença da Artéria Coronariana/epidemiologia , Feminino , Frequência do Gene , Estudo de Associação Genômica Ampla , Humanos , Masculino , Razão de Chances , Polimorfismo de Nucleotídeo Único
11.
Nature ; 542(7640): 186-190, 2017 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-28146470

RESUMO

Height is a highly heritable, classic polygenic trait with approximately 700 common associated variants identified through genome-wide association studies so far. Here, we report 83 height-associated coding variants with lower minor-allele frequencies (in the range of 0.1-4.8%) and effects of up to 2 centimetres per allele (such as those in IHH, STC2, AR and CRISPLD2), greater than ten times the average effect of common variants. In functional follow-up studies, rare height-increasing alleles of STC2 (giving an increase of 1-2 centimetres per allele) compromised proteolytic inhibition of PAPP-A and increased cleavage of IGFBP-4 in vitro, resulting in higher bioavailability of insulin-like growth factors. These 83 height-associated variants overlap genes that are mutated in monogenic growth disorders and highlight new biological candidates (such as ADAMTS3, IL11RA and NOX4) and pathways (such as proteoglycan and glycosaminoglycan synthesis) involved in growth. Our results demonstrate that sufficiently large sample sizes can uncover rare and low-frequency variants of moderate-to-large effect associated with polygenic human phenotypes, and that these variants implicate relevant genes and pathways.


Assuntos
Estatura/genética , Frequência do Gene/genética , Variação Genética/genética , Proteínas ADAMTS/genética , Adulto , Alelos , Moléculas de Adesão Celular/genética , Feminino , Genoma Humano/genética , Glicoproteínas/genética , Glicoproteínas/metabolismo , Glicosaminoglicanos/biossíntese , Proteínas Hedgehog/genética , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Fatores Reguladores de Interferon/genética , Subunidade alfa de Receptor de Interleucina-11/genética , Masculino , Herança Multifatorial/genética , NADPH Oxidase 4 , NADPH Oxidases/genética , Fenótipo , Proteína Plasmática A Associada à Gravidez/metabolismo , Pró-Colágeno N-Endopeptidase/genética , Proteoglicanas/biossíntese , Proteólise , Receptores Androgênicos/genética , Somatomedinas/metabolismo
12.
Blood ; 129(4): 520-524, 2017 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-28064200

RESUMO

The von Willebrand receptor complex, which is composed of the glycoproteins Ibα, Ibß, GPV, and GPIX, plays an essential role in the earliest steps in hemostasis. During the last 4 decades, it has become apparent that loss of function of any 1 of 3 of the genes encoding these glycoproteins (namely, GP1BA, GP1BB, and GP9) leads to autosomal recessive macrothrombocytopenia complicated by bleeding. A small number of variants in GP1BA have been reported to cause a milder and dominant form of macrothrombocytopenia, but only 2 tentative reports exist of such a variant in GP1BB By analyzing data from a collection of more than 1000 genome-sequenced patients with a rare bleeding and/or platelet disorder, we have identified a significant association between rare monoallelic variants in GP1BB and macrothrombocytopenia. To strengthen our findings, we sought further cases in 2 additional collections in the United Kingdom and Japan. Across 18 families exhibiting phenotypes consistent with autosomal dominant inheritance of macrothrombocytopenia, we report on 27 affected cases carrying 1 of 9 rare variants in GP1BB.


Assuntos
Plaquetas/metabolismo , Hemorragia/genética , Mutação , Complexo Glicoproteico GPIb-IX de Plaquetas/genética , Trombocitopenia/genética , Alelos , Plaquetas/patologia , Estudos de Casos e Controles , Feminino , Expressão Gênica , Genes Dominantes , Genoma Humano , Hemorragia/diagnóstico , Hemorragia/metabolismo , Hemorragia/patologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Linhagem , Contagem de Plaquetas , Trombocitopenia/diagnóstico , Trombocitopenia/metabolismo , Trombocitopenia/patologia
13.
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
14.
Nat Genet ; 48(10): 1151-1161, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27618447

RESUMO

High blood pressure is a major risk factor for cardiovascular disease and premature death. However, there is limited knowledge on specific causal genes and pathways. To better understand the genetics of blood pressure, we genotyped 242,296 rare, low-frequency and common genetic variants in up to 192,763 individuals and used ∼155,063 samples for independent replication. We identified 30 new blood pressure- or hypertension-associated genetic regions in the general population, including 3 rare missense variants in RBM47, COL21A1 and RRAS with larger effects (>1.5 mm Hg/allele) than common variants. Multiple rare nonsense and missense variant associations were found in A2ML1, and a low-frequency nonsense variant in ENPEP was identified. Our data extend the spectrum of allelic variation underlying blood pressure traits and hypertension, provide new insights into the pathophysiology of hypertension and indicate new targets for clinical intervention.


Assuntos
Pressão Sanguínea/genética , Variação Genética , Hipertensão/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Genótipo , Humanos
15.
Hum Mol Genet ; 25(18): 4094-4106, 2016 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-27466198

RESUMO

It has been hypothesized that low frequency (1-5% minor allele frequency (MAF)) and rare (<1% MAF) variants with large effect sizes may contribute to the missing heritability in complex traits. Here, we report an association analysis of lipid traits (total cholesterol, LDL-cholesterol, HDL-cholesterol triglycerides) in up to 27 312 individuals with a comprehensive set of low frequency coding variants (ExomeChip), combined with conditional analysis in the known lipid loci. No new locus reached genome-wide significance. However, we found a new lead variant in 26 known lipid association regions of which 16 were >1000-fold more significant than the previous sentinel variant and not in close LD (six had MAF <5%). Furthermore, conditional analysis revealed multiple independent signals (ranging from 1 to 5) in a third of the 98 lipid loci tested, including rare variants. Addition of our novel associations resulted in between 1.5- and 2.5-fold increase in the proportion of heritability explained for the different lipid traits. Our findings suggest that rare coding variants contribute to the genetic architecture of lipid traits.


Assuntos
HDL-Colesterol/genética , LDL-Colesterol/genética , Metabolismo dos Lipídeos/genética , Lipídeos/genética , Adolescente , Adulto , Idoso , Criança , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Grupo com Ancestrais do Continente Europeu , Exoma/genética , Frequência do Gene , Estudo de Associação Genômica Ampla , Humanos , Lipídeos/sangue , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Triglicerídeos/sangue , Triglicerídeos/genética
16.
Blood ; 128(14): 1879-1883, 2016 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-27436851

RESUMO

Thrombomodulin-associated coagulopathy (TM-AC) is a newly recognized dominant bleeding disorder in which a p.Cys537Stop variant in the thrombomodulin (TM) gene THBD, results in high plasma TM levels and protein C-mediated suppression of thrombin generation. Thrombin in complex with TM also activates thrombin-activatable fibrinolysis inhibitor (TAFI). However, the effect of the high plasma TM on fibrinolysis in TM-AC is unknown. Plasma from TM-AC cases and high-TM model control samples spiked with recombinant soluble TM showed reduced tissue factor-induced thrombin generation. Lysis of plasma clots from TM-AC cases was significantly delayed compared with controls but was completely restored when TM/thrombin-mediated TAFI activation was inhibited. Clots formed in blood from TM-AC cases had the same viscoelastic strength as controls but also showed a TAFI-dependent delay in fibrinolysis. Delayed fibrinolysis was reproduced in high-TM model plasma and blood samples. Partial restoration of thrombin generation with recombinant activated factor VII or activated prothrombin complex concentrate did not alter the delayed fibrinolysis in high-TM model blood. Our finding of a previously unrecognized fibrinolytic phenotype indicates that bleeding in TM-AC has a complex pathogenesis and highlights the pivotal role of TM as a regulator of hemostasis.


Assuntos
Transtornos da Coagulação Sanguínea/metabolismo , Fibrinólise , Trombomodulina/metabolismo , Adulto , Fator VIIa/farmacologia , Feminino , Fibrinólise/efeitos dos fármacos , Genes Dominantes , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Fenótipo , Protrombina/farmacologia , Proteínas Recombinantes/farmacologia , Trombina/metabolismo
17.
Sci Transl Med ; 8(328): 328ra30, 2016 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-26936507

RESUMO

The Src family kinase (SFK) member SRC is a major target in drug development because it is activated in many human cancers, yet deleterious SRC germline mutations have not been reported. We used genome sequencing and Human Phenotype Ontology patient coding to identify a gain-of-function mutation in SRC causing thrombocytopenia, myelofibrosis, bleeding, and bone pathologies in nine cases. Modeling of the E527K substitution predicts loss of SRC's self-inhibitory capacity, which we confirmed with in vitro studies showing increased SRC kinase activity and enhanced Tyr(419) phosphorylation in COS-7 cells overexpressing E527K SRC. The active form of SRC predominates in patients' platelets, resulting in enhanced overall tyrosine phosphorylation. Patients with myelofibrosis have hypercellular bone marrow with trilineage dysplasia, and their stem cells grown in vitro form more myeloid and megakaryocyte (MK) colonies than control cells. These MKs generate platelets that are dysmorphic, low in number, highly variable in size, and have a paucity of α-granules. Overactive SRC in patient-derived MKs causes a reduction in proplatelet formation, which can be rescued by SRC kinase inhibition. Stem cells transduced with lentiviral E527K SRC form MKs with a similar defect and enhanced tyrosine phosphorylation levels. Patient-derived and E527K-transduced MKs show Y419 SRC-positive stained podosomes that induce altered actin organization. Expression of mutated src in zebrafish recapitulates patients' blood and bone phenotypes. Similar studies of platelets and MKs may reveal the mechanism underlying the severe bleeding frequently observed in cancer patients treated with next-generation SFK inhibitors.


Assuntos
Osso e Ossos/patologia , Hemorragia/genética , Mutação/genética , Mielofibrose Primária/genética , Trombocitopenia/genética , Quinases da Família src/genética , Animais , Plaquetas/patologia , Células COS , Feminino , Hematopoese , Hemorragia/complicações , Humanos , Masculino , Linhagem , Fenótipo , Mielofibrose Primária/complicações , Trombocitopenia/complicações , Transfecção , Peixe-Zebra
18.
N Engl J Med ; 374(12): 1134-44, 2016 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-26934567

RESUMO

BACKGROUND: The discovery of low-frequency coding variants affecting the risk of coronary artery disease has facilitated the identification of therapeutic targets. METHODS: Through DNA genotyping, we tested 54,003 coding-sequence variants covering 13,715 human genes in up to 72,868 patients with coronary artery disease and 120,770 controls who did not have coronary artery disease. Through DNA sequencing, we studied the effects of loss-of-function mutations in selected genes. RESULTS: We confirmed previously observed significant associations between coronary artery disease and low-frequency missense variants in the genes LPA and PCSK9. We also found significant associations between coronary artery disease and low-frequency missense variants in the genes SVEP1 (p.D2702G; minor-allele frequency, 3.60%; odds ratio for disease, 1.14; P=4.2×10(-10)) and ANGPTL4 (p.E40K; minor-allele frequency, 2.01%; odds ratio, 0.86; P=4.0×10(-8)), which encodes angiopoietin-like 4. Through sequencing of ANGPTL4, we identified 9 carriers of loss-of-function mutations among 6924 patients with myocardial infarction, as compared with 19 carriers among 6834 controls (odds ratio, 0.47; P=0.04); carriers of ANGPTL4 loss-of-function alleles had triglyceride levels that were 35% lower than the levels among persons who did not carry a loss-of-function allele (P=0.003). ANGPTL4 inhibits lipoprotein lipase; we therefore searched for mutations in LPL and identified a loss-of-function variant that was associated with an increased risk of coronary artery disease (p.D36N; minor-allele frequency, 1.9%; odds ratio, 1.13; P=2.0×10(-4)) and a gain-of-function variant that was associated with protection from coronary artery disease (p.S447*; minor-allele frequency, 9.9%; odds ratio, 0.94; P=2.5×10(-7)). CONCLUSIONS: We found that carriers of loss-of-function mutations in ANGPTL4 had triglyceride levels that were lower than those among noncarriers; these mutations were also associated with protection from coronary artery disease. (Funded by the National Institutes of Health and others.).


Assuntos
Angiopoietinas/genética , Moléculas de Adesão Celular/genética , Doença da Artéria Coronariana/genética , Lipase Lipoproteica/genética , Mutação , Triglicerídeos/sangue , Idoso , Proteína 4 Semelhante a Angiopoietina , Feminino , Técnicas de Genotipagem , Humanos , Lipase Lipoproteica/antagonistas & inibidores , Lipase Lipoproteica/metabolismo , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Fatores de Risco , Análise de Sequência de DNA , Triglicerídeos/genética
19.
Thorax ; 71(6): 501-9, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26917578

RESUMO

BACKGROUND: Several regions of the genome have shown to be associated with COPD in genome-wide association studies of common variants. OBJECTIVE: To determine rare and potentially functional single nucleotide polymorphisms (SNPs) associated with the risk of COPD and severity of airflow limitation. METHODS: 3226 current or former smokers of European ancestry with lung function measures indicative of Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2 COPD or worse were genotyped using an exome array. An analysis of risk of COPD was carried out using ever smoking controls (n=4784). Associations with %predicted FEV1 were tested in cases. We followed-up signals of interest (p<10(-5)) in independent samples from a subset of the UK Biobank population and also undertook a more powerful discovery study by meta-analysing the exome array data and UK Biobank data for variants represented on both arrays. RESULTS: Among the associated variants were two in regions previously unreported for COPD; a low frequency non-synonymous SNP in MOCS3 (rs7269297, pdiscovery=3.08×10(-6), preplication=0.019) and a rare SNP in IFIT3, which emerged in the meta-analysis (rs140549288, pmeta=8.56×10(-6)). In the meta-analysis of % predicted FEV1 in cases, the strongest association was shown for a splice variant in a previously unreported region, SERPINA12 (rs140198372, pmeta=5.72×10(-6)). We also confirmed previously reported associations with COPD risk at MMP12, HHIP, GPR126 and CHRNA5. No associations in novel regions reached a stringent exome-wide significance threshold (p<3.7×10(-7)). CONCLUSIONS: This study identified several associations with the risk of COPD and severity of airflow limitation, including novel regions MOCS3, IFIT3 and SERPINA12, which warrant further study.


Assuntos
Obstrução das Vias Respiratórias/genética , Obstrução das Vias Respiratórias/fisiopatologia , Peptídeos e Proteínas de Sinalização Intracelular/genética , Nucleotidiltransferases/genética , Polimorfismo de Nucleotídeo Único , Doença Pulmonar Obstrutiva Crônica/genética , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Serpinas/genética , Sulfurtransferases/genética , Idoso , Exoma , Feminino , Volume Expiratório Forçado/genética , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Medição de Risco , Fumar/epidemiologia
20.
Blood ; 127(23): 2903-14, 2016 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-26912466

RESUMO

Macrothrombocytopenia (MTP) is a heterogeneous group of disorders characterized by enlarged and reduced numbers of circulating platelets, sometimes resulting in abnormal bleeding. In most MTP, this phenotype arises because of altered regulation of platelet formation from megakaryocytes (MKs). We report the identification of DIAPH1, which encodes the Rho-effector diaphanous-related formin 1 (DIAPH1), as a candidate gene for MTP using exome sequencing, ontological phenotyping, and similarity regression. We describe 2 unrelated pedigrees with MTP and sensorineural hearing loss that segregate with a DIAPH1 R1213* variant predicting partial truncation of the DIAPH1 diaphanous autoregulatory domain. The R1213* variant was linked to reduced proplatelet formation from cultured MKs, cell clustering, and abnormal cortical filamentous actin. Similarly, in platelets, there was increased filamentous actin and stable microtubules, indicating constitutive activation of DIAPH1. Overexpression of DIAPH1 R1213* in cells reproduced the cytoskeletal alterations found in platelets. Our description of a novel disorder of platelet formation and hearing loss extends the repertoire of DIAPH1-related disease and provides new insight into the autoregulation of DIAPH1 activity.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Perda Auditiva/genética , Mutação , Trombocitopenia/genética , Células A549 , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Células Cultivadas , Criança , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Células HEK293 , Perda Auditiva/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Polimorfismo de Nucleotídeo Único , Síndrome , Trombocitopenia/complicações , Adulto Jovem
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