Disease Directory Hereditary Hemorrhagic Telangiectasia
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Hereditary Hemorrhagic Telangiectasia

Also known as: HHT, Osler-Weber-Rendu disease, Osler-Rendu-Weber syndrome

Prevalence

1 in 5,000 to 1 in 8,000

Onset

Telangiectasias and nosebleeds typically emerge in adolescence to adulthood; AVMs may be congenital

Type

Autosomal dominant

Gene

ENG, ACVRL1

About Hereditary Hemorrhagic Telangiectasia

Hereditary hemorrhagic telangiectasia is a vascular dysplasia syndrome caused by heterozygous loss-of-function mutations in genes encoding components of the TGF-beta/BMP signaling pathway, most commonly ENG (endoglin, HHT type 1) or ACVRL1 (activin receptor-like kinase 1, HHT type 2), leading to abnormal arteriovenous connections in multiple organs. These arteriovenous malformations (AVMs) most frequently affect the nasal mucosa, gastrointestinal tract, lungs, liver, and brain, causing recurrent hemorrhage and in severe cases high-output cardiac failure or paradoxical embolism. The diagnosis is clinical using the Curacao criteria and confirmed by genetic testing.

Common Clinical Features

Recurrent spontaneous epistaxis (nosebleeds) as the hallmark symptom Multiple mucocutaneous telangiectasias on lips, tongue, fingers, and face Gastrointestinal bleeding from intestinal telangiectasias Pulmonary arteriovenous malformations causing hypoxemia and risk of stroke Cerebral AVMs with risk of hemorrhagic stroke or brain abscess Hepatic AVMs potentially causing high-output heart failure or portal hypertension Iron deficiency anemia from chronic blood loss Migraine headaches

Clinical Trial Eligibility Tips

What to know before applying to Hereditary Hemorrhagic Telangiectasia trials.

Confirmed HHT diagnosis using Curacao criteria (at least 3 of 4: epistaxis, telangiectasias, visceral AVMs, family history) or genetic mutation identification is required for most trials; bring genetic test results and imaging of AVMs.

Severity of epistaxis (frequency, duration, transfusion dependence, Epistaxis Severity Score) and iron deficiency status are primary outcomes in antiangiogenic therapy trials including bevacizumab and thalidomide studies.

Screening for pulmonary and cerebral AVMs is recommended before enrollment in any study involving systemic agents, as untreated large pulmonary AVMs increase procedural risk.

Patient Resources

Patient Organization

Cure HHT

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Natural History Registry

HHT International Registry

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Orphanet

European reference resource for rare diseases (ORPHA:774)

View on Orphanet ↗

NORD

National Organization for Rare Disorders

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Find recruiting Hereditary Hemorrhagic Telangiectasia trials

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