Osler Weber Rendu syndrome

Osler-Weber-Rendu Syndrome Osler-Weber-Rendu Syndrome, 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). These can lead to frequent nosebleeds, bleeding in other areas, and complications due to AVMs in major organs.

Etiology

Osler-Weber-Rendu Syndrome 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 blood vessel formation and maintenance.

Clinical Features

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

• Telangiectasias: Small, red spots that appear on the skin and mucous membranes, particularly on the face, lips, and inside the mouth.
• Nosebleeds (Epistaxis): Frequent and recurrent nosebleeds are often one of the first signs of the disease.
• Arteriovenous Malformations (AVMs): Abnormal connections between arteries and veins that can occur in the lungs, brain, liver, and other organs.

Diagnosis

Diagnosis of Osler-Weber-Rendu Syndrome 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. A diagnosis is considered definite if three or more criteria are present, possible if two are present, and unlikely if fewer than two are present.

Management

Management of Osler-Weber-Rendu Syndrome 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, brain, and liver, and treatment if necessary.
• Genetic counseling: For affected individuals and their families.

Complications

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

• Pulmonary AVMs: Can lead to hypoxemia, brain abscesses, and strokes.
• Cerebral AVMs: Risk of hemorrhagic stroke.
• Hepatic AVMs: Can cause high-output heart failure and portal hypertension.

Research and Future Directions

Research into Osler-Weber-Rendu Syndrome is ongoing, with studies focusing on understanding the genetic basis of the disease, improving diagnostic methods, and developing new treatments. Gene therapy and targeted molecular therapies are areas of active investigation.

See Also

• Telangiectasia
• Arteriovenous malformation
• Genetic counseling
• "Hereditary Hemorrhagic Telangiectasia: A Review of Clinical Features and Management." Journal of Vascular Medicine.
• "Genetic Insights into Osler-Weber-Rendu Syndrome." Genetics in Medicine.

NIH genetic and rare disease info

• NIH info on Osler Weber Rendu syndrome

Osler Weber Rendu syndrome is a rare disease.