Patients with hereditary hemorrhagic telangiectasia (HHT) suffer from an inherited disorder leading to systemic vascular malformations. Mutations in several genes of the transforming growth factor (TGF)-β superfamily pathway influence angiogenesis in patients with HHT. The genetic loss of ALK1 or ENG alone are not sufficient to induce AVMs; environmental insults that could trigger angiogenesis (e.g. wounding) are also needed. In this study it will be analyzed if hypoxic induced factors could have an influence on the disease HHT.

Hereditary hemorrhagic telangiectasia (HHT) is characterized by systemic vascular malformations leading to recurrent bleedings and shunt formation especially in the liver, lungs and the brain. The underlying pathogenic HHT mechanism remains unclear. The wide variability in age of onset and severity of symptoms amongst patients, even within the same family, suggests several factors contribute to the complexity of this disease. Mutations in several genes of the transforming growth factor (TGF)-β superfamily pathway influence angiogenesis in patients with HHT. The genetic loss of ALK1 or ENG alone are not sufficient to induce AVMs; environmental insults that could trigger angiogenesis (e.g. wounding) are also needed. In this study it will be analyzed if hypoxic induced factors could have an influence on the disease HHT.

Inclusion Criteria:

• diagnosed HHT (genetic testing and/ or fulfill at least 3 Curacao Criteria)
• older than 17 years
• ability to consent

Exclusion Criteria:

• if inclusion Criteria are not met

Patients with diagnosed hereditary hemorrhagic telangiectasie (HHT)