Hereditary hemorrhagic telangiectasia (HHT) can be fatal. However, it does not affect the average life expectancy of most people. Complications can occur when blood vessels rupture in vital organs.

Researchers renamed Osler-Weber-Rendu syndrome HHT because the new name better describes the condition.

The cause of HHT is hereditary, meaning a person inherits gene alterations from a parent to develop symptoms. Telangiectasias are a type of arteriovenous malformation (AVM). This refers to small, excessively dilated blood vessels that develop close to the skin or in mucus membranes. Not all telangiectasias, such as those on the face, pose a health risk. However, those that develop in the lungs, brain, and gastrointestinal (GI) tract can be lethal.

Currently, HHT has no cure. As such, the goal of treatment is symptom management. This may involve iron supplementation, blood transfusions, and laser treatments to shrink blood vessels.

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HHT is usually only fatal when blood vessels rupture in the lungs, brain, or other vital organs.

This is more likely to happen when a person does not know they have HHT and has not received treatment. If a person has an HHT diagnosis and health care professionals help them manage it, they will likely have a healthy life expectancy.

The severity of an HHT complication depends on where the bleed occurs. A persistent nosebleed, for example, still requires treatment, and a person can lose a lot of blood, but it is unlikely to be fatal.

Other potential complications that range in severity include:

HHT is a genetic condition. This means a person develops the condition after inheriting a gene alteration from a parent.

HHT is an autosomal dominant bleeding condition, meaning a person only needs to inherit one copy of the gene variation to develop symptoms. As such, there is a 50% risk of someone inheriting the condition if one parent has HHT.

Rarely, though, a person’s genes can change spontaneously. They may have been born with healthy genes, but for some unknown reason, those genes have changed and now cause symptoms. At the moment, researchers have identified five different genes that can cause HHT when they mutate.

HHT is a condition in which blood vessels do not develop properly, and there are often unusual connections between capillary networks. When arteries and veins do not have healthy capillary networks, there is a greater risk of rupturing or bleeding. Nosebleeds are the most common symptom of HHT because the nose contains many small capillaries.

HHT also affects blood vessels in the:

  • hands
  • fingertips
  • face
  • lips
  • lining of the mouth
  • digestive tract
  • liver
  • lungs
  • brain

Bleeds within the brain, lungs, and liver often do not have warning signs and can happen suddenly, which is why they can be lethal.

Initially, a doctor will ask questions about a person’s family medical history, as HHT is a genetic condition.

To help confirm a diagnosis of HHT, a doctor will need to observe at least three of the following:

  • Nosebleeds: These must be recurring and spontaneous.
  • Telangiectasias: These are usually red or purple spots that turn pale when pressed.
  • Poorly developed blood vessels: These are in one or more internal organs, for example, the brain, spine, or lungs.
  • A family history of HHT: An immediate family member with HHT, such as a parent, sibling, or child must have the condition.

Treatment for HHT focuses on managing symptoms, as doctors currently cannot target the genes responsible. Doctors ideally want to remove telangiectasias from vital organs, such as the brain and lungs, where a bleed could be lethal.

Techniques doctors use to remove telangiectasias include:

  • embolization
  • laser removal
  • stereotactic radiation treatment
  • surgical removal

For other bleeds, for example, those in the mouth and nose, doctors prefer to manage symptoms before removing damaged blood vessels due to potential complications.

Osler-Weber-Rendu syndrome is a bleeding disorder people can inherit or develop. Researchers renamed it hereditary hemorrhagic telangiectasia (HHT), as it better describes the condition. Because HHT is autosomal dominant, a person only needs one copy of the gene alteration from one parent to develop symptoms.

Unfortunately, researchers have yet to find a gene therapy that targets the faulty gene in this genetic condition. Instead, doctors focus on managing symptoms, such as reducing the risk of infection and anemia. If fragile blood vessels develop in vital organs, a person may undergo surgery or embolization.