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Excerpted from the GeneReview: Hereditary Hemorrhagic Telangiectasia
Hereditary hemorrhagic telangiectasia (HHT) is characterized by the presence of multiple arteriovenous malformations (AVMs) that lack intervening capillaries and result in direct connections between arteries and veins. The most common clinical manifestation is spontaneous and recurrent nosebleeds (epistaxis) beginning on average at age 12 years. Telangiectases (small AVMs) are most evident on the lips, tongue, buccal mucosa, face, chest, and fingers. The average age of onset is generally later than epistaxis, but may be during childhood. Large AVMs often cause symptoms when they occur in the lungs, liver, or brain; complications from bleeding or shunting may be sudden and catastrophic. Approximately 25% of individuals with HHT have GI bleeding, which most commonly begins after age 50 years.

Genes See tests for all associated and related genes

  • Also known as: DPC4, JIP, MADH4, MYHRS, SMAD4
    Summary: SMAD family member 4

Clinical features


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Suggested reading

  • Shovlin et al., 2000
    Diagnostic criteria for hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome).

Practice guidelines

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