Hereditary haemorrhagic telangiectasia: current views on genetics and mechanisms of disease.
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ABSTRACT:
SUBMITTER: Abdalla SA
PROVIDER: S-EPMC2603035 | biostudies-literature | 2006 Feb
REPOSITORIES: biostudies-literature
Publications
Hereditary haemorrhagic telangiectasia: current views on genetics and mechanisms of disease.
Journal of medical genetics 20050506 2
Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterised by epistaxis, telangiectases, and multiorgan vascular dysplasia. The two major types of disease, HHT1 and HHT2, are caused by mutations in the ENG (endoglin) and ACVRL1 genes, respectively. The corresponding endoglin and ALK-1 proteins are specific endothelial receptors of the transforming growth factor beta superfamily essential for maintaining vascular integrity. Many mutations have been identified in ...[more]
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Project description:Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterised by vascular malformations in multiple organ systems, resulting in mucocutaneous telangiectases and arteriovenous malformations predominantly in the lungs (pulmonary arteriovenous malformation; PAVM), brain (cerebral arteriovenous malformation; CAVM), and liver (hepatic arteriovenous malformation; HAVM). Mutations in the ENG and ALK-1 genes lead to HHT1 and HHT2 respectively. In this study, a genotype-phenotype analysis was performed. A uniform and well classified large group of HHT patients and their family members were screened for HHT manifestations. Groups of patients with a clinically confirmed diagnosis and/or genetically established diagnosis (HHT1 or HHT2) were compared. The frequency of PAVM, CAVM, HAVM, and gastrointestinal telangiectases were determined to establish the genotype-phenotype relationship. The analysis revealed differences between HHT1 and HHT2 and within HHT1 and HHT2 between men and women. PAVMs and CAVMs occur more often in HHT1, whereas HAVMs are more frequent in HHT2. Furthermore, there is a higher prevalence of PAVM in women compared with men in HHT1. In HHT1 and HHT2, there is a higher frequency of HAVM in women. HHT1 has a distinct, more severe phenotype than HHT2. There is a difference in the presence of symptoms between men and women. With these data, genetic counselling can be given more accurately when the family mutation is known.
| S-EPMC2563220 | biostudies-literature
Project description:The autosomal-dominant trait hereditary haemorrhagic telangiectasia (HHT) affects 1 in 5-8000 people. Genes mutated in HHT (most commonly for endoglin or activin receptor-like kinase (ALK1)) encode proteins that modulate transforming growth factor (TGF)-beta superfamily signalling in vascular endothelial cells; mutations lead to the development of fragile telangiectatic vessels and arteriovenous malformations. In this article, we review the underlying molecular, cellular and circulatory pathobiology; explore HHT clinical and genetic diagnostic strategies; present detailed considerations regarding screening for asymptomatic visceral involvement; and provide overviews of management strategies.
| S-EPMC2986493 | biostudies-literature
Project description:BackgroundHereditary Haemorrhagic Telangiectasia (HHT) is an autosomal dominant disease associated with epistaxis, arteriovenous malformations and telangiectasias. Disease complications may result in premature death.MethodWe investigated life-expectancies of parents of HHT patients compared with their non-HHT partners using self- or telephone-administered questionnaires sent to their children. Patients were extracted from the databases of 2 participating HHT Centres: the Toronto HHT Database (Toronto, Canada) and the St. Antonius Hospital HHT Database (Nieuwegein, The Netherlands).ResultsTwo hundred twenty five/407 (55%) of respondents were included creating HHT- (n = 225) and control groups (n = 225) of equal size. Two hundred thirteen/225 (95%) of the HHT group had not been screened for organ involvement of the disease prior to death. The life expectancy in parents with HHT was slightly lower compared to parents without (median age at death 73.3 years in patients versus 76.6 years in controls, p0.018). Parents with ACVRL 1 mutations had normal life expectancies, whereas parents with Endoglin mutations died 7.1 years earlier than controls (p = 0.024). Women with Endoglin mutations lived a median of 9.3 years shorter than those without (p = 0.04). Seven/123 (5%) of deaths were HHT related with a median age at death of 61.5 years (IQ range 54.4-67.7 years).ConclusionOur study showed that the life expectancy of largely unscreened HHT patients was lower than people without HHT. Female patients with Endoglin mutations were most strikingly at risk of premature death from complications. These results emphasize the importance of referring patients with HHT for screening of organ involvement and timely intervention to prevent complications.
| S-EPMC4841052 | biostudies-literature
Project description:Hereditary Haemorrhagic Telangiectasia (HHT) is an autosomal dominantly inherited vascular disease characterized by the presence of mucocutaneous telangiectasia and arteriovenous malformations in visceral organs. HHT is predominantly caused by mutations in ENG and ACVRL1, Which both belong to the TGF-β signalling pathway. Further knowledge on how a disturbance of the TGF-β signalling pathway leads to HHT manifestations is needed in order to identify potential therapeutic targets. As long non-coding RNAs (lncRNAs) are increasingly recognized as key regulators of gene expression and constitute a sizable fraction of the human transcriptome, we wanted to assess whether lncRNAs play a role in the molecular pathogenesis of HHT. Here we used microarray analysis to profile lncRNAs to compare the expression of HHT telangiectasial and HHT non-telangiectasial nasal tissue from the same patient in a paired design. The microarray probes were re-annotated using the GENCODE v.16 dataset, identifying 4,810 probes mapping to 2,811 lncRNAs. By comparing HHT telangiectasial tissue versus HHT non-telangiectasial tissue, we identified 42 lncRNAs that are differentially expressed (q<0.001). Using GREAT, a tool that assumes cis-regulation, we showed that differently expressed lncRNAs are enriched for genomic loci involved in key pathways concerning HHT. Our study identified lncRNAs that are aberrantly expressed in HHT telangiectasia and indicates that lncRNAs may contribute to regulate protein-coding loci in HHT. Which suggest that the lncRNA component of the transcriptome deserves more attention in HHT. A deeper understanding of lncRNAs and their role in telangiectasia formation possesses potential for discovering therapeutic targets in HHT.
2014-12-19 | GSE53515 | GEO
Project description:Patients with hereditary haemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber syndrome, suffer from the consequences of abnormal vessel structures. These structures can lead to haemorrhages or shunt effects in liver, lungs and brain. This inherited and rare disease is characterized by mutations affecting the transforming growth factor-β (TGF-β)/Bone Morphogenetic Protein (BMP) pathway that results in arteriovenous malformations and studies indicate an impaired immune response. The mechanism underlying this altered immune response in HHT patients is still unknown. TGF-β interacts with hypoxia inducible factors (HIF), which both orchestrate inflammatory and angiogenic processes. Therefore, we analysed the expression of HIF and related genes in whole blood samples from HHT patients. We could show significantly decreased expression of HIF-1α on the mRNA and protein level. However, commonly known upstream regulators of HIF-1α in inflammatory responses were not affected, whereas HIF-1α target genes were significantly downregulated. There was no correlation between HIF1A or HIF2A gene expression and the severity of HHT detected. Our results represent a rare case of HIF-1α downregulation in a human disease, which underlines the relevance of HIFs in HHT. The study indicates an interaction of the known mutation in HHT and the dysregulation of HIF-1α in HHT patients, which might contribute to the clinical phenotype.
| S-EPMC8988913 | biostudies-literature
Project description:Hereditary Haemorrhagic Telangiectasia (HHT) is an autosomal dominantly inherited vascular disease characterized by the presence of mucocutaneous telangiectasia and arteriovenous malformations in visceral organs. HHT is predominantly caused by mutations in ENG and ACVRL1, Which both belong to the TGF-M-NM-2 signalling pathway. Further knowledge on how a disturbance of the TGF-M-NM-2 signalling pathway leads to HHT manifestations is needed in order to identify potential therapeutic targets. As long non-coding RNAs (lncRNAs) are increasingly recognized as key regulators of gene expression and constitute a sizable fraction of the human transcriptome, we wanted to assess whether lncRNAs play a role in the molecular pathogenesis of HHT. Here we used microarray analysis to profile lncRNAs to compare the expression of HHT telangiectasial and HHT non-telangiectasial nasal tissue from the same patient in a paired design. The microarray probes were re-annotated using the GENCODE v.16 dataset, identifying 4,810 probes mapping to 2,811 lncRNAs. By comparing HHT telangiectasial tissue versus HHT non-telangiectasial tissue, we identified 42 lncRNAs that are differentially expressed (q<0.001). Using GREAT, a tool that assumes cis-regulation, we showed that differently expressed lncRNAs are enriched for genomic loci involved in key pathways concerning HHT. Our study identified lncRNAs that are aberrantly expressed in HHT telangiectasia and indicates that lncRNAs may contribute to regulate protein-coding loci in HHT. Which suggest that the lncRNA component of the transcriptome deserves more attention in HHT. A deeper understanding of lncRNAs and their role in telangiectasia formation possesses potential for discovering therapeutic targets in HHT. Gene expression profiling of 80 paired nasal samples from patients with hereditary Haemorrhagic Telangiectasia (HHT), representing telangiectasial and non-telangiectasial (normal) tissue respectively. The patients were divided into HHT1 or HHT2 in regard to the germline mutation in ENG (HHT1) or ACVRL1 (HHT2). Additional controls were healthy siblings (not carrying the germline mutation) and external controls. The study was conducted using Agilent-028004 SurePrint G3 Human GE 8x60K Microarray platform.
2014-12-19 | E-GEOD-53515 | biostudies-arrayexpress
Project description:Hereditary Haemorrhagic Telangiectasia (HHT) is an autosomal dominantly inherited vascular disease characterized by the presence of mucocutaneous telangiectasia and arteriovenous malformations in visceral organs. HHT is predominantly caused by mutations in ENG and ACVRL1, which both belong to the TGF-β signalling pathway. The exact mechanism of how haploinsufficiency of ENG and ACVRL1 leads to HHT manifestations remains to be identified. As long non-coding RNAs (lncRNAs) are increasingly recognized as key regulators of gene expression and constitute a sizable fraction of the human transcriptome, we wanted to assess whether lncRNAs play a role in the molecular pathogenesis of HHT manifestations. By microarray technology, we profiled lncRNA transcripts from HHT nasal telangiectasial and non-telangiectasial tissue using a paired design. The microarray probes were annotated using the GENCODE v.16 dataset, identifying 4,810 probes mapping to 2,811 lncRNAs. Comparing HHT telangiectasial tissue with HHT non-telangiectasial tissue, we identified 42 lncRNAs that are differentially expressed (q<0.001). Using GREAT, a tool that assumes cis-regulation, we showed that differently expressed lncRNAs are enriched for genomic loci involved in key pathways concerning HHT. Our study identified lncRNAs that are aberrantly expressed in HHT telangiectasia and indicates that lncRNAs may contribute to regulate protein-coding loci in HHT. These results suggest that the lncRNA component of the transcriptome deserves more attention in HHT. A deeper understanding of lncRNAs and their role in telangiectasia formation possesses potential for discovering therapeutic targets in HHT.
| S-EPMC3946172 | biostudies-literature
Project description:BackgroundThere are very few studies about general quality of life parameters, standards for the description of health status and comparison with general population data on patients with Hereditary hemorrhagic telangiectasia (HHT), a rare disease in which epistaxis is a cardinal symptom.PurposeTo assess the quality of life in a population of Spanish patients with HHT and compare it with the general population.Design and methodsBetween January 1st 2005 and December 31st 2013, 187 adult patients diagnosed with HHT who were admitted to the HHT Unit of the Hospital Sierrallana, completed on their first visit, the EuroQol 5D-3L (five dimensions and three levels) quality of life descriptive test and the visual analog scale (VAS). The numerical social index value was also determined and the subjective effect of the nasal epistaxis on their quality of life was estimated classified as mild, moderate or severe.ResultsPatients with HHT had greater problems than the general population in the five dimensions of the EuroQol 5D-3L, particularly considering pain/discomfort and anxiety/depression. In the VAS and the social index value, patients with HHT also scored lower than the general population, particularly older patients, males, and patients with HHT2. They also had values similar to those of populations with chronic illnesses. The subjective perception of the severity of epistaxis correlated strongly with the VAS and social index values.ConclusionsThe quality of life of patients with HHT, estimated using the EuroQol 5D-3L scale, is affected across all dimensions. The scores are similar to those seen in cases of other chronic diseases. Older patients, males and the carriers of the ACVRL1 mutation generally have worse scores on these scales. The VAS and the social index value are index that correlate well with the severity of the clinical symptoms associated mainly with epistaxis.
| S-EPMC5259834 | biostudies-literature
Project description:BackgroundHereditary haemorrhagic telangiectasia (HHT) is a genetic disorder present in 1 in 8000 people and associated with arteriovenous malformations. Genetic testing can identify individuals at risk of developing the disease and is a useful diagnostic tool.ObjectiveTo present a strategy for mutation detection in families clinically diagnosed with HHT.MethodsAn optimised strategy for detecting mutations that predispose to HHT is presented. The strategy includes quantitative multiplex polymerase chain reaction, sequence analysis, RNA analysis, validation of missense mutations by amino acid conservation analysis for the ENG (endoglin) and ACVRL1 (ALK1) genes, and analysis of an ACVRL1 protein structural model. If no causative ENG or ACVRL1 mutation is found, proband samples are referred for sequence analysis of MADH4 (associated with a combined syndrome of juvenile polyposis and HHT).ResultsData obtained over the past eight years were summarised and 16 novel mutations described. Mutations were identified in 155 of 194 families with a confirmed clinical diagnosis (80% sensitivity). Of 155 mutations identified, 94 were in ENG (61%), 58 in ACVRL1 (37%), and three in MADH4 (2%).ConclusionsFor most missense variants of ENG and ACVRL1 reported to date, study of amino acid conservation showed good concordance between prediction of altered protein function and disease occurrence. The 39 families (20%) yet to be resolved may carry ENG, ACVRL1, or MADH4 mutations too complex or difficult to detect, or mutations in genes yet to be identified.
| S-EPMC2564570 | biostudies-literature
Project description:ObjectiveTo retrospectively describe a large series of pregnancies in women with hereditary haemorrhagic telangiectasia followed in our reference centre, plus neonatal outcomes, to better understand the risks of complications and to improve their prevention.DesignA retrospective descriptive study conducted through a phone questionnaire.SettingReference centre for hereditary haemorrhagic telangiectasia in Lyon, France.PopulationWomen meeting the following criteria: (1) alive and aged ≥18 years; (2) with a definite clinical and/or genetic diagnosis of hereditary haemorrhagic telangiectasia; and (3) with at least one full-term pregnancy.Main outcome measuresMaternal and perinatal outcomes of pregnancies in women with hereditary haemorrhagic telangiectasia.ResultsFive hundred and sixty-two pregnancies were reported in 207 women with hereditary haemorrhagic telangiectasia. A total of 271 complications (48.2%) were registered. Of these, 149 (55%) non-specific complications, 110 (40.6%) non-severe specific complications and 12 (4.4%) severe specific complications were registered. There were four cases of haemoptysis and two cases of transient ischaemic attack related to pulmonary arteriovenous malformations. Four patients had severe decompensated dyspnoea, related to pulmonary arteriovenous malformations in three cases and to pulmonary arteriovenous malformations associated with severe hepatic arteriovenous malformations in one case. Hepatobiliary necrosis occurred in one case. Epidural or spinal anaesthesia was performed in 139 of 452 deliveries (31%), without complications. There were 12 reports of congenital anomalies in 461 live births (3%).ConclusionsMost pregnancies in hereditary haemorrhagic telangiectasia women are uneventful; complications are rare but can be severe. Women thus need to be educated about screening and possible pregnancy-related risks before becoming pregnant.
| S-EPMC10092409 | biostudies-literature