Rendu-Osler-Weber disease

Rendu-Osler-Weber Disease Rendu-Osler-Weber disease, also known as Hereditary Hemorrhagic Telangiectasia (HHT), is a genetic disorder that affects blood vessels throughout the body. It is characterized by the development of abnormal blood vessels called telangiectasias and arteriovenous malformations (AVMs). This condition can lead to frequent nosebleeds, bleeding in other areas of the body, and various complications depending on the location of the AVMs.

Etiology

Rendu-Osler-Weber disease is an autosomal dominant disorder, meaning that a single copy of the mutated gene inherited from an affected parent can cause the disease. The most common genes associated with HHT are ENG, ACVRL1, and SMAD4. Mutations in these genes lead to abnormalities in the blood vessels.

Clinical Features

The clinical presentation of Rendu-Osler-Weber disease can vary widely among individuals, but common features include:

• Telangiectasias: Small, dilated blood vessels visible on the skin and mucous membranes, often found on the face, lips, tongue, and fingers.
• Nosebleeds (Epistaxis): Frequent and recurrent nosebleeds are often the first symptom and can be severe.
• Arteriovenous Malformations (AVMs): Abnormal connections between arteries and veins that can occur in various organs, including the lungs, liver, and brain.

Diagnosis

Diagnosis of Rendu-Osler-Weber disease is based on clinical criteria known as the Cura ao criteria, which include: 1. Recurrent spontaneous nosebleeds. 2. Multiple telangiectasias at characteristic sites. 3. Visceral lesions such as AVMs. 4. A family history of HHT. Genetic testing can confirm the diagnosis by identifying mutations in the associated genes.

Management

Management of Rendu-Osler-Weber disease focuses on controlling symptoms and preventing complications. This may include:

• Nosebleed management: Humidification, topical treatments, and in some cases, surgical interventions.
• Screening and treatment of AVMs: Regular screening for AVMs in the lungs, liver, and brain, with treatment options including embolization or surgery.
• Iron supplementation: To address anemia caused by chronic bleeding.

Complications

Complications of Rendu-Osler-Weber disease can be serious and include:

• Severe anemia: Due to chronic blood loss.
• Pulmonary AVMs: Can lead to hypoxemia, brain abscesses, or strokes.
• Cerebral AVMs: Risk of hemorrhagic stroke.
• Hepatic AVMs: Can cause high-output heart failure or portal hypertension.

Epidemiology

Rendu-Osler-Weber disease affects approximately 1 in 5,000 to 1 in 10,000 people worldwide. It is equally prevalent in males and females and occurs in all ethnic groups.

Research and Future Directions

Research into Rendu-Osler-Weber disease is ongoing, with studies focusing on understanding the genetic mechanisms, improving diagnostic methods, and developing targeted therapies to manage the disease more effectively.

See Also

• Telangiectasia
• Arteriovenous malformation
• Genetic disorders

External Links

• [HHT Foundation International](https://curehht.org/)
• Genetic and Rare Diseases Information Center

NIH genetic and rare disease info

• NIH info on Rendu-Osler-Weber disease

Rendu-Osler-Weber disease is a rare disease.