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1.
Eur Respir J ; 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31744833

RESUMO

Pulmonary arterial hypertension (PAH) is a rare disease that leads to premature death from right heart failure. It is strongly associated with elevated red cell distribution width (RDW), a correlate of several iron status biomarkers. High RDW values can signal early stage iron deficiency or iron deficiency anaemia. This study investigated if elevated RDW is causally associated with PAH.A two-sample Mendelian randomisation (MR) approach was applied to investigate whether genetic predisposition to higher levels of RDW increases the odds of developing PAH. Primary and secondary MR analyses were performed using all available genome-wide significant RDW variants (n=179) and five genome-wide significant RDW variants that act via systemic iron status, respectively.We confirmed the observed association between RDW and PAH (OR=1.90, 95% CI=1.80-2.01) in a multi-centre case-control study (N cases=642, N disease controls=15 889). The primary MR analysis was adequately powered to detect a causal effect (OR) from between 1.25 and 1.52 or greater based on estimates reported in the RDW GWAS or from our own data. There was no evidence for a causal association between RDW and PAH in either the primary (ORcausal=1.07, 95% CI=0.92-1.24) or the secondary (ORcausal=1.09, 95% CI=0.77-1.54) MR analysis.The results suggest that at least some of the observed association of RDW with PAH is secondary to disease progression. Results of iron therapeutic trials in PAH should be interpreted with caution as any improvements observed may not be mechanistically linked to the development of PAH.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31661308

RESUMO

OBJECTIVES: Recently, rare heterozygous mutations in GDF2 were identified in patients with pulmonary arterial hypertension (PAH). GDF2 encodes the circulating bone morphogenetic protein, BMP9, which is a ligand for the BMP type 2 receptor (BMPR2). Here we determine the functional impact of GDF2 mutations and characterised plasma BMP9 and BMP10 levels in patients with idiopathic PAH. METHODS: Missense BMP9 mutant proteins were expressed in vitro and the impact on BMP9 protein processing and secretion, endothelial signalling and functional activity was assessed. Plasma BMP9 and BMP10 levels and activity were assayed in PAH patients with GDF2 mutations, and controls. Levels were also measured in a larger cohort of controls (n=120) and idiopathic PAH patients (n=260). MAIN RESULTS: We identified novel rare variation at the GDF2 and BMP10 loci, including copy number variation. In vitro, BMP9 missense proteins demonstrated impaired cellular processing and secretion. PAH patients carrying these mutations exhibited reduced plasma levels of BMP9 and reduced BMP activity. Unexpectedly, plasma BMP10 levels were also markedly reduced in these individuals. Although overall BMP9 and BMP10 levels did not differ between PAH patients and controls, BMP10 levels were lower in PAH females. A subset of PAH patients had markedly reduced plasma levels of BMP9 and BMP10 in the absence of GDF2 mutations. CONCLUSIONS: Our findings demonstrate that GDF2 mutations result in BMP9 loss-of-function and are likely causal. These mutations lead to reduced circulating levels of both BMP9 and BMP10. These findings support therapeutic strategies to enhance BMP9 or BMP10 signalling in PAH.

3.
Nat Rev Cardiol ; 2019 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-31406341

RESUMO

Pulmonary arterial hypertension (PAH) is a rare, progressive disorder typified by occlusion of the pulmonary arterioles owing to endothelial dysfunction and uncontrolled proliferation of pulmonary artery smooth muscle cells and fibroblasts. Vascular occlusion can lead to increased pressure in the pulmonary arteries, often resulting in right ventricular failure with shortness of breath and syncope. Since the identification of BMPR2, which encodes a receptor in the transforming growth factor-ß superfamily, the development of high-throughput sequencing approaches to identify novel causal genes has substantially advanced our understanding of the molecular genetics of PAH. In the past 6 years, additional pathways involved in PAH susceptibility have been described through the identification of deleterious genetic variants in potassium channels (KCNK3 and ABCC8) and transcription factors (TBX4 and SOX17), among others. Although familial PAH most often has an autosomal-dominant pattern of inheritance, cases of incomplete penetrance and evidence of genetic heterogeneity support a model of PAH as a Mendelian disorder with complex disease features. In this Review, we outline the latest advances in the detection of rare and common genetic variants underlying PAH susceptibility and disease progression. These findings have clinical implications for lung vascular function and can help to identify mechanistic pathways amenable to pharmacological intervention.

4.
Lancet Respir Med ; 7(3): 227-238, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30527956

RESUMO

BACKGROUND: Rare genetic variants cause pulmonary arterial hypertension, but the contribution of common genetic variation to disease risk and natural history is poorly characterised. We tested for genome-wide association for pulmonary arterial hypertension in large international cohorts and assessed the contribution of associated regions to outcomes. METHODS: We did two separate genome-wide association studies (GWAS) and a meta-analysis of pulmonary arterial hypertension. These GWAS used data from four international case-control studies across 11 744 individuals with European ancestry (including 2085 patients). One GWAS used genotypes from 5895 whole-genome sequences and the other GWAS used genotyping array data from an additional 5849 individuals. Cross-validation of loci reaching genome-wide significance was sought by meta-analysis. Conditional analysis corrected for the most significant variants at each locus was used to resolve signals for multiple associations. We functionally annotated associated variants and tested associations with duration of survival. All-cause mortality was the primary endpoint in survival analyses. FINDINGS: A locus near SOX17 (rs10103692, odds ratio 1·80 [95% CI 1·55-2·08], p=5·13 × 10-15) and a second locus in HLA-DPA1 and HLA-DPB1 (collectively referred to as HLA-DPA1/DPB1 here; rs2856830, 1·56 [1·42-1·71], p=7·65 × 10-20) within the class II MHC region were associated with pulmonary arterial hypertension. The SOX17 locus had two independent signals associated with pulmonary arterial hypertension (rs13266183, 1·36 [1·25-1·48], p=1·69 × 10-12; and rs10103692). Functional and epigenomic data indicate that the risk variants near SOX17 alter gene regulation via an enhancer active in endothelial cells. Pulmonary arterial hypertension risk variants determined haplotype-specific enhancer activity, and CRISPR-mediated inhibition of the enhancer reduced SOX17 expression. The HLA-DPA1/DPB1 rs2856830 genotype was strongly associated with survival. Median survival from diagnosis in patients with pulmonary arterial hypertension with the C/C homozygous genotype was double (13·50 years [95% CI 12·07 to >13·50]) that of those with the T/T genotype (6·97 years [6·02-8·05]), despite similar baseline disease severity. INTERPRETATION: This is the first study to report that common genetic variation at loci in an enhancer near SOX17 and in HLA-DPA1/DPB1 is associated with pulmonary arterial hypertension. Impairment of SOX17 function might be more common in pulmonary arterial hypertension than suggested by rare mutations in SOX17. Further studies are needed to confirm the association between HLA typing or rs2856830 genotyping and survival, and to determine whether HLA typing or rs2856830 genotyping improves risk stratification in clinical practice or trials. FUNDING: UK NIHR, BHF, UK MRC, Dinosaur Trust, NIH/NHLBI, ERS, EMBO, Wellcome Trust, EU, AHA, ACClinPharm, Netherlands CVRI, Dutch Heart Foundation, Dutch Federation of UMC, Netherlands OHRD and RNAS, German DFG, German BMBF, APH Paris, INSERM, Université Paris-Sud, and French ANR.

5.
Hum Mutat ; 39(9): 1246-1261, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29924900

RESUMO

Adams-Oliver syndrome (AOS) is a rare developmental disorder, characterized by scalp aplasia cutis congenita (ACC) and transverse terminal limb defects (TTLD). Autosomal dominant forms of AOS are linked to mutations in ARHGAP31, DLL4, NOTCH1 or RBPJ, while DOCK6 and EOGT underlie autosomal recessive inheritance. Data on the frequency and distribution of mutations in large cohorts are currently limited. The purpose of this study was therefore to comprehensively examine the genetic architecture of AOS in an extensive cohort. Molecular diagnostic screening of 194 AOS/ACC/TTLD probands/families was conducted using next-generation and/or capillary sequencing analyses. In total, we identified 63 (likely) pathogenic mutations, comprising 56 distinct and 22 novel mutations, providing a molecular diagnosis in 30% of patients. Taken together with previous reports, these findings bring the total number of reported disease variants to 63, with a diagnostic yield of 36% in familial cases. NOTCH1 is the major contributor, underlying 10% of AOS/ACC/TTLD cases, with DLL4 (6%), DOCK6 (6%), ARHGAP31 (3%), EOGT (3%), and RBPJ (2%) representing additional causality in this cohort. We confirm the relevance of genetic screening across the AOS/ACC/TTLD spectrum, highlighting preliminary but important genotype-phenotype correlations. This cohort offers potential for further gene identification to address missing heritability.

6.
Nat Commun ; 9(1): 1416, 2018 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-29650961

RESUMO

Pulmonary arterial hypertension (PAH) is a rare disorder with a poor prognosis. Deleterious variation within components of the transforming growth factor-ß pathway, particularly the bone morphogenetic protein type 2 receptor (BMPR2), underlies most heritable forms of PAH. To identify the missing heritability we perform whole-genome sequencing in 1038 PAH index cases and 6385 PAH-negative control subjects. Case-control analyses reveal significant overrepresentation of rare variants in ATP13A3, AQP1 and SOX17, and provide independent validation of a critical role for GDF2 in PAH. We demonstrate familial segregation of mutations in SOX17 and AQP1 with PAH. Mutations in GDF2, encoding a BMPR2 ligand, lead to reduced secretion from transfected cells. In addition, we identify pathogenic mutations in the majority of previously reported PAH genes, and provide evidence for further putative genes. Taken together these findings contribute new insights into the molecular basis of PAH and indicate unexplored pathways for therapeutic intervention.


Assuntos
Adenosina Trifosfatases/química , Aquaporina 1/química , Hipertensão Pulmonar Primária Familiar/genética , Fatores de Diferenciação de Crescimento/química , Proteínas de Membrana Transportadoras/química , Mutação , Fatores de Transcrição SOXF/química , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Adulto , Aquaporina 1/genética , Aquaporina 1/metabolismo , Sequência de Bases , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/genética , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/metabolismo , Estudos de Casos e Controles , Hipertensão Pulmonar Primária Familiar/diagnóstico , Hipertensão Pulmonar Primária Familiar/metabolismo , Hipertensão Pulmonar Primária Familiar/patologia , Feminino , Regulação da Expressão Gênica , Predisposição Genética para Doença , Fatores de Diferenciação de Crescimento/genética , Fatores de Diferenciação de Crescimento/metabolismo , Células HEK293 , Humanos , Masculino , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Modelos Moleculares , Prognóstico , Fatores de Transcrição SOXF/genética , Fatores de Transcrição SOXF/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Sequenciamento Completo do Genoma
7.
Circulation ; 136(21): 2022-2033, 2017 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-28972005

RESUMO

BACKGROUND: Pulmonary arterial hypertension (PAH) is a rare disease with an emerging genetic basis. Heterozygous mutations in the gene encoding the bone morphogenetic protein receptor type 2 (BMPR2) are the commonest genetic cause of PAH, whereas biallelic mutations in the eukaryotic translation initiation factor 2 alpha kinase 4 gene (EIF2AK4) are described in pulmonary veno-occlusive disease/pulmonary capillary hemangiomatosis. Here, we determine the frequency of these mutations and define the genotype-phenotype characteristics in a large cohort of patients diagnosed clinically with PAH. METHODS: Whole-genome sequencing was performed on DNA from patients with idiopathic and heritable PAH and with pulmonary veno-occlusive disease/pulmonary capillary hemangiomatosis recruited to the National Institute of Health Research BioResource-Rare Diseases study. Heterozygous variants in BMPR2 and biallelic EIF2AK4 variants with a minor allele frequency of <1:10 000 in control data sets and predicted to be deleterious (by combined annotation-dependent depletion, PolyPhen-2, and sorting intolerant from tolerant predictions) were identified as potentially causal. Phenotype data from the time of diagnosis were also captured. RESULTS: Eight hundred sixty-four patients with idiopathic or heritable PAH and 16 with pulmonary veno-occlusive disease/pulmonary capillary hemangiomatosis were recruited. Mutations in BMPR2 were identified in 130 patients (14.8%). Biallelic mutations in EIF2AK4 were identified in 5 patients with a clinical diagnosis of pulmonary veno-occlusive disease/pulmonary capillary hemangiomatosis. Furthermore, 9 patients with a clinical diagnosis of PAH carried biallelic EIF2AK4 mutations. These patients had a reduced transfer coefficient for carbon monoxide (Kco; 33% [interquartile range, 30%-35%] predicted) and younger age at diagnosis (29 years; interquartile range, 23-38 years) and more interlobular septal thickening and mediastinal lymphadenopathy on computed tomography of the chest compared with patients with PAH without EIF2AK4 mutations. However, radiological assessment alone could not accurately identify biallelic EIF2AK4 mutation carriers. Patients with PAH with biallelic EIF2AK4 mutations had a shorter survival. CONCLUSIONS: Biallelic EIF2AK4 mutations are found in patients classified clinically as having idiopathic and heritable PAH. These patients cannot be identified reliably by computed tomography, but a low Kco and a young age at diagnosis suggests the underlying molecular diagnosis. Genetic testing can identify these misclassified patients, allowing appropriate management and early referral for lung transplantation.


Assuntos
Pressão Arterial/genética , Hipertensão Pulmonar/genética , Mutação , Proteínas Serina-Treonina Quinases/genética , Artéria Pulmonar/fisiopatologia , Adulto , Idoso , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/genética , Análise Mutacional de DNA , Europa (Continente) , Feminino , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Hereditariedade , Humanos , Hipertensão Pulmonar/diagnóstico , Hipertensão Pulmonar/enzimologia , Hipertensão Pulmonar/fisiopatologia , Masculino , Pessoa de Meia-Idade , Linhagem , Fenótipo , Valor Preditivo dos Testes , Estudos Prospectivos , Estudos Retrospectivos , Fatores de Risco , Tomografia Computadorizada por Raios X , Adulto Jovem
9.
Science ; 352(6284): 474-7, 2016 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-26940866

RESUMO

Examining complete gene knockouts within a viable organism can inform on gene function. We sequenced the exomes of 3222 British adults of Pakistani heritage with high parental relatedness, discovering 1111 rare-variant homozygous genotypes with predicted loss of function (knockouts) in 781 genes. We observed 13.7% fewer homozygous knockout genotypes than we expected, implying an average load of 1.6 recessive-lethal-equivalent loss-of-function (LOF) variants per adult. When genetic data were linked to the individuals' lifelong health records, we observed no significant relationship between gene knockouts and clinical consultation or prescription rate. In this data set, we identified a healthy PRDM9-knockout mother and performed phased genome sequencing on her, her child, and control individuals. Our results show that meiotic recombination sites are localized away from PRDM9-dependent hotspots. Thus, natural LOF variants inform on essential genetic loci and demonstrate PRDM9 redundancy in humans.


Assuntos
Consanguinidade , Saúde , Histona-Lisina N-Metiltransferase/genética , Adulto , Análise Mutacional de DNA , Prescrições de Medicamentos , Exoma/genética , Feminino , Fertilidade , Técnicas de Inativação de Genes , Genes Letais , Loci Gênicos , Genoma Humano , Recombinação Homóloga , Homozigoto , Humanos , Masculino , Mães , Paquistão/etnologia , Fenótipo , Reino Unido
10.
Hum Mutat ; 36(11): 1112, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26457590

RESUMO

The original article to which this Erratum refers was published in Human Mutation 36(6):593­598(DOI:10.1002/humu22795).The authors realized that a co-author, Nuria C. Bramswig, was left off of the title page of this article at the time of submission. This erratum serves to correct this error by including Dr. Bramswig and Dr. Bramswig's institution in the title page information.The authors regret the error.

11.
Hum Mutat ; 36(12): 1113-27, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26387786

RESUMO

Pulmonary arterial hypertension (PAH) is an often fatal disorder resulting from several causes including heterogeneous genetic defects. While mutations in the bone morphogenetic protein receptor type II (BMPR2) gene are the single most common causal factor for hereditary cases, pathogenic mutations have been observed in approximately 25% of idiopathic PAH patients without a prior family history of disease. Additional defects of the transforming growth factor beta pathway have been implicated in disease pathogenesis. Specifically, studies have confirmed activin A receptor type II-like 1 (ACVRL1), endoglin (ENG), and members of the SMAD family as contributing to PAH both with and without associated clinical phenotypes. Most recently, next-generation sequencing has identified novel, rare genetic variation implicated in the PAH disease spectrum. Of importance, several identified genetic factors converge on related pathways and provide significant insight into the development, maintenance, and pathogenetic transformation of the pulmonary vascular bed. Together, these analyses represent the largest comprehensive compilation of BMPR2 and associated genetic risk factors for PAH, comprising known and novel variation. Additionally, with the inclusion of an allelic series of locus-specific variation in BMPR2, these data provide a key resource in data interpretation and development of contemporary therapeutic and diagnostic tools.


Assuntos
Hipertensão Pulmonar/genética , Animais , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/química , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/genética , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/metabolismo , Modelos Animais de Doenças , Estudos de Associação Genética , Aconselhamento Genético , Predisposição Genética para Doença , Variação Genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Hipertensão Pulmonar/diagnóstico , Hipertensão Pulmonar/metabolismo , Família Multigênica , Mutação , Transdução de Sinais , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo
12.
Hum Mutat ; 36(12): 1135-44, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26394720

RESUMO

Genetic heterogeneity presents a significant challenge for the identification of monogenic disease genes. Whole-exome sequencing generates a large number of candidate disease-causing variants and typical analyses rely on deleterious variants being observed in the same gene across several unrelated affected individuals. This is less likely to occur for genetically heterogeneous diseases, making more advanced analysis methods necessary. To address this need, we present HetRank, a flexible gene-ranking method that incorporates interaction network data. We first show that different genes underlying the same monogenic disease are frequently connected in protein interaction networks. This motivates the central premise of HetRank: those genes carrying potentially pathogenic variants and whose network neighbors do so in other affected individuals are strong candidates for follow-up study. By simulating 1,000 exome sequencing studies (20,000 exomes in total), we model varying degrees of genetic heterogeneity and show that HetRank consistently prioritizes more disease-causing genes than existing analysis methods. We also demonstrate a proof-of-principle application of the method to prioritize genes causing Adams-Oliver syndrome, a genetically heterogeneous rare disease. An implementation of HetRank in R is available via the Website http://sourceforge.net/p/hetrank/.


Assuntos
Biologia Computacional/métodos , Exoma , Estudos de Associação Genética/métodos , Heterogeneidade Genética , Sequenciamento de Nucleotídeos em Larga Escala , Software , Simulação por Computador , Epistasia Genética , Redes Reguladoras de Genes , Doenças Genéticas Inatas/genética , Doenças Genéticas Inatas/metabolismo , Humanos , Mapeamento de Interação de Proteínas/métodos , Navegador
13.
Am J Hum Genet ; 97(3): 475-82, 2015 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-26299364

RESUMO

Adams-Oliver syndrome (AOS) is a rare developmental disorder characterized by the presence of aplasia cutis congenita (ACC) of the scalp vertex and terminal limb-reduction defects. Cardiovascular anomalies are also frequently observed. Mutations in five genes have been identified as a cause for AOS prior to this report. Mutations in EOGT and DOCK6 cause autosomal-recessive AOS, whereas mutations in ARHGAP31, RBPJ, and NOTCH1 lead to autosomal-dominant AOS. Because RBPJ, NOTCH1, and EOGT are involved in NOTCH signaling, we hypothesized that mutations in other genes involved in this pathway might also be implicated in AOS pathogenesis. Using a candidate-gene-based approach, we prioritized DLL4, a critical NOTCH ligand, due to its essential role in vascular development in the context of cardiovascular features in AOS-affected individuals. Targeted resequencing of the DLL4 gene with a custom enrichment panel in 89 independent families resulted in the identification of seven mutations. A defect in DLL4 was also detected in two families via whole-exome or genome sequencing. In total, nine heterozygous mutations in DLL4 were identified, including two nonsense and seven missense variants, the latter encompassing four mutations that replace or create cysteine residues, which are most likely critical for maintaining structural integrity of the protein. Affected individuals with DLL4 mutations present with variable clinical expression with no emerging genotype-phenotype correlations. Our findings demonstrate that DLL4 mutations are an additional cause of autosomal-dominant AOS or isolated ACC and provide further evidence for a key role of NOTCH signaling in the etiology of this disorder.


Assuntos
Displasia Ectodérmica/genética , Displasia Ectodérmica/patologia , Peptídeos e Proteínas de Sinalização Intercelular/genética , Deformidades Congênitas dos Membros/genética , Deformidades Congênitas dos Membros/patologia , Mutação/genética , Dermatoses do Couro Cabeludo/congênito , Transdução de Sinais/genética , Sequência de Aminoácidos , Sequência de Bases , Heterozigoto , Humanos , Dados de Sequência Molecular , Linhagem , Receptores Notch/genética , Dermatoses do Couro Cabeludo/genética , Dermatoses do Couro Cabeludo/patologia , Análise de Sequência de DNA
14.
Circ Cardiovasc Genet ; 8(4): 572-581, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25963545

RESUMO

BACKGROUND: Adams-Oliver syndrome (AOS) is a rare disorder characterized by congenital limb defects and scalp cutis aplasia. In a proportion of cases, notable cardiac involvement is also apparent. Despite recent advances in the understanding of the genetic basis of AOS, for the majority of affected subjects, the underlying molecular defect remains unresolved. This study aimed to identify novel genetic determinants of AOS. METHODS AND RESULTS: Whole-exome sequencing was performed for 12 probands, each with a clinical diagnosis of AOS. Analyses led to the identification of novel heterozygous truncating NOTCH1 mutations (c.1649dupA and c.6049_6050delTC) in 2 kindreds in which AOS was segregating as an autosomal dominant trait. Screening a cohort of 52 unrelated AOS subjects, we detected 8 additional unique NOTCH1 mutations, including 3 de novo amino acid substitutions, all within the ligand-binding domain. Congenital heart anomalies were noted in 47% (8/17) of NOTCH1-positive probands and affected family members. In leukocyte-derived RNA from subjects harboring NOTCH1 extracellular domain mutations, we observed significant reduction of NOTCH1 expression, suggesting instability and degradation of mutant mRNA transcripts by the cellular machinery. Transient transfection of mutagenized NOTCH1 missense constructs also revealed significant reduction in gene expression. Mutant NOTCH1 expression was associated with downregulation of the Notch target genes HEY1 and HES1, indicating that NOTCH1-related AOS arises through dysregulation of the Notch signaling pathway. CONCLUSIONS: These findings highlight a key role for NOTCH1 across a range of developmental anomalies that include cardiac defects and implicate NOTCH1 haploinsufficiency as a likely molecular mechanism for this group of disorders.


Assuntos
Displasia Ectodérmica/genética , Predisposição Genética para Doença/genética , Haploinsuficiência , Cardiopatias Congênitas/genética , Deformidades Congênitas dos Membros/genética , Receptor Notch1/genética , Dermatoses do Couro Cabeludo/congênito , Adolescente , Adulto , Sequência de Bases , Criança , Exoma/genética , Saúde da Família , Feminino , Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Moleculares , Linhagem , Estrutura Terciária de Proteína , Receptor Notch1/química , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Dermatoses do Couro Cabeludo/genética , Análise de Sequência de DNA/métodos , Transdução de Sinais/genética , Adulto Jovem
15.
Hum Mutat ; 36(6): 593-8, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25824905

RESUMO

Adams-Oliver syndrome (AOS) is characterized by the association of aplasia cutis congenita with terminal transverse limb defects, often accompanied by additional cardiovascular or neurological features. Both autosomal-dominant and autosomal-recessive disease transmission have been observed, with recent gene discoveries indicating extensive genetic heterogeneity. Mutations of the DOCK6 gene were first described in autosomal-recessive cases of AOS and only five DOCK6-related families have been reported to date. Recently, a second type of autosomal-recessive AOS has been attributed to EOGT mutations in three consanguineous families. Here, we describe the identification of 13 DOCK6 mutations, the majority of which are novel, across 10 unrelated individuals from a large cohort comprising 47 sporadic cases and 31 AOS pedigrees suggestive of autosomal-recessive inheritance. DOCK6 mutations were strongly associated with structural brain abnormalities, ocular anomalies, and intellectual disability, thus suggesting that DOCK6-linked disease represents a variant of AOS with a particularly poor prognosis.


Assuntos
Encéfalo/anormalidades , Displasia Ectodérmica/diagnóstico , Displasia Ectodérmica/genética , Anormalidades do Olho/genética , Genes Recessivos , Estudos de Associação Genética , Fatores de Troca do Nucleotídeo Guanina/genética , Deformidades Congênitas dos Membros/diagnóstico , Deformidades Congênitas dos Membros/genética , Mutação , Dermatoses do Couro Cabeludo/congênito , Adolescente , Encéfalo/patologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Imagem por Ressonância Magnética , Masculino , Dermatoses do Couro Cabeludo/diagnóstico , Dermatoses do Couro Cabeludo/genética , Tomografia Computadorizada por Raios X , Adulto Jovem
17.
Hum Mutat ; 32(12): 1385-9, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21898662

RESUMO

Heterozygous germline mutations of BMPR2 contribute to familial clustering of pulmonary arterial hypertension (PAH). To further explore the genetic basis of PAH in isolated cases, we undertook a candidate gene analysis to identify potentially deleterious variation. Members of the bone morphogenetic protein (BMP) pathway, namely SMAD1, SMAD4, SMAD5, and SMAD9, were screened by direct sequencing for gene defects. Four variants were identified in SMADs 1, 4, and 9 among a cohort of 324 PAH cases, each not detected in a substantial control population. Of three amino acid substitutions identified, two demonstrated reduced signaling activity in vitro. A putative splice site mutation in SMAD4 resulted in moderate transcript loss due to compromised splicing efficiency. These results demonstrate the role of BMPR2 mutation in the pathogenesis of PAH and indicate that variation within the SMAD family represents an infrequent cause of the disease.


Assuntos
Hipertensão Pulmonar/genética , Transdução de Sinais/genética , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/genética , Estudos de Coortes , Hipertensão Pulmonar Primária Familiar , Feminino , Regulação da Expressão Gênica , Humanos , Masculino , Análise de Sequência de DNA , Proteína Smad1/genética , Proteína Smad8/genética
18.
Am J Hum Genet ; 88(5): 574-85, 2011 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-21565291

RESUMO

Regulation of cell proliferation and motility is essential for normal development. The Rho family of GTPases plays a critical role in the control of cell polarity and migration by effecting the cytoskeleton, membrane trafficking, and cell adhesion. We investigated a recognized developmental disorder, Adams-Oliver syndrome (AOS), characterized by the combination of aplasia cutis congenita (ACC) and terminal transverse limb defects (TTLD). Through a genome-wide linkage analysis, we detected a locus for autosomal-dominant ACC-TTLD on 3q generating a maximum LOD score of 4.93 at marker rs1464311. Candidate-gene- and exome-based sequencing led to the identification of independent premature truncating mutations in the terminal exon of the Rho GTPase-activating protein 31 gene, ARHGAP31, which encodes a Cdc42/Rac1 regulatory protein. Mutant transcripts are stable and increase ARHGAP31 activity in vitro through a gain-of-function mechanism. Constitutively active ARHGAP31 mutations result in a loss of available active Cdc42 and consequently disrupt actin cytoskeletal structures. Arhgap31 expression in the mouse is substantially restricted to the terminal limb buds and craniofacial processes during early development; these locations closely mirror the sites of impaired organogenesis that characterize this syndrome. These data identify the requirement for regulated Cdc42 and/or Rac1 signaling processes during early human development.


Assuntos
Displasia Ectodérmica/genética , Proteínas Ativadoras de GTPase/genética , Mutação , Actinas/metabolismo , Adesão Celular , Movimento Celular , Polaridade Celular , Proliferação de Células , Mapeamento Cromossômico , Citoesqueleto/metabolismo , Análise Mutacional de DNA , Displasia Ectodérmica/embriologia , Feminino , Regulação da Expressão Gênica , Células HEK293 , Células HeLa , Humanos , Deformidades Congênitas dos Membros/embriologia , Deformidades Congênitas dos Membros/genética , Masculino , Dermatoses do Couro Cabeludo/congênito , Dermatoses do Couro Cabeludo/embriologia , Dermatoses do Couro Cabeludo/genética , Transdução de Sinais , Proteína cdc42 de Ligação ao GTP/metabolismo , Proteínas rac1 de Ligação ao GTP/metabolismo
19.
Hum Mutat ; 32(2): 231-9, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21280149

RESUMO

Dyggve-Melchior-Clausen syndrome (DMC), a severe autosomal recessive skeletal disorder with mental retardation, is caused by mutation of the gene encoding Dymeclin (DYM). Employing patient fibroblasts with mutations characterized at the genomic and, for the first time, transcript level, we identified profound disruption of Golgi organization as a pathogenic feature, resolved by transfection of heterologous wild-type Dymeclin. Collagen targeting appeared defective in DMC cells leading to near complete absence of cell surface collagen fibers. DMC cells have an elevated apoptotic index (P< 0.01) likely due to a stress response contingent upon Golgi-related trafficking defects. We performed spatiotemporal mapping of Dymeclin expression in zebrafish embryos and identified high levels of transcript in brain and cartilage during early development. Finally, in a chondrocyte cDNA library, we identified two novel secretion pathway proteins as Dymeclin interacting partners: GOLM1 and PPIB. Together these data identify the role of Dymeclin in secretory pathways essential to endochondral bone formation during early development.


Assuntos
Desenvolvimento Ósseo , Matriz Extracelular/metabolismo , Complexo de Golgi/metabolismo , Proteínas/metabolismo , Animais , Células Cultivadas , Condrogênese , Citoplasma/metabolismo , Nanismo/metabolismo , Fibroblastos/metabolismo , Doenças Genéticas Ligadas ao Cromossomo X/metabolismo , Células HeLa , Humanos , Deficiência Intelectual/metabolismo , Mutação , Osteocondrodisplasias/congênito , Osteocondrodisplasias/metabolismo , Pele/citologia , Técnicas do Sistema de Duplo-Híbrido , Peixe-Zebra/embriologia
20.
Nat Genet ; 42(10): 906-9, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20835238

RESUMO

We conducted a genome-wide association study for primary open-angle glaucoma (POAG) in 1,263 affected individuals (cases) and 34,877 controls from Iceland. We identified a common sequence variant at 7q31 (rs4236601[A], odds ratio (OR) = 1.36, P = 5.0 × 10⁻¹°). We then replicated the association in sample sets of 2,175 POAG cases and 2,064 controls from Sweden, the UK and Australia (combined OR = 1.18, P = 0.0015) and in 299 POAG cases and 580 unaffected controls from Hong Kong and Shantou, China (combined OR = 5.42, P = 0.0021). The risk variant identified here is located close to CAV1 and CAV2, both of which are expressed in the trabecular meshwork and retinal ganglion cells that are involved in the pathogenesis of POAG.


Assuntos
Caveolina 1/genética , Caveolina 2/genética , Predisposição Genética para Doença , Genoma Humano , Estudo de Associação Genômica Ampla , Glaucoma de Ângulo Aberto/genética , Polimorfismo de Nucleotídeo Único/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Cromossomos Humanos Par 7/genética , Feminino , Genótipo , Glaucoma de Ângulo Aberto/patologia , Humanos , Masculino , Pessoa de Meia-Idade
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