Hereditary Hemorrhagic Telangiectasia (HHT)

Hereditary Hemorrhagic Telangiectasia (HHT), previously called Osler-Weber-Rendu disease, is a disorder of the vascular system that affects many parts of the body. HHT is characterized by the presence of telangiectasias (dilated blood vessels) and multiple arteriovenous malformations (AVMs) that lack intervening capillaries and result in direct connections between arteries and veins. The symptoms of HHT can be highly variable, even between affected members of the same family.

Complications individuals with HHT may experience include:

  • Telangiectasias of the nose which result in nosebleeds of varying severity (affects ~90% of people with HHT)
  • Telangiectasias of skin and hands which are usually benign
  • Telangiectasias in the GI system that can lead to GI bleeding. Affects ~30% of people with HHT, symptoms may include black/bloody stools or anemia
  • Pulmonary AVMs that increase risk for stroke or brain abscess and that can rupture. These affect ~40% of people with HHT and can be present early in life
  • Brain AVMs, which are thought to be present from birth and often do not cause warning symptoms prior to hemorrhage. Affects ~10% of people with HHT.
  • Liver telangiectasias/AVMs, which are usually asymptomatic (occur in ~75% of HHT patients)

It is important for individuals with HHT to be diagnosed as early in life as possible and then managed appropriately to prevent complications. It is recommended that individuals with HHT be comprehensively screened at multidisciplinary centers with experience in HHT diagnosis, management, and surveillance, specifically CureHHT-accredited HHT Centers of Excellence.

Genetic testing identifies the specific genetic cause for HHT in someone with a clinical diagnosis (defined through the Curacao criteria) over 90% of the time. Genetic testing can also be helpful when a patient meets some but not all criteria for a clinical diagnosis of HHT and there is no (known) family history. And finally, genetic testing can also differentiate between a clinical diagnosis of HHT and a similar condition known as Capillary Malformation-Arteriovenous Malformation syndrome (CM-AVM).

When the specific variant (mutation) is known, we can then help identify at-risk family members who may not meet all the diagnostic criteria. HHT is a dominant condition, meaning an affected individual has a 50% risk of passing down the diagnosis with each pregnancy. It is important to note that a negative genetic testing result doesn't change a clinical diagnosis of HHT as someone could have HHT due to a genetic mutation not detected with current testing. Having support from a genetic counselor can help individuals understand those limitations and stay up to date on the latest information on the diagnosis.

What to Expect:

A genetic counselor identifies genetic risk by reviewing each patient’s medical history in addition to taking a thorough family history. They have specialized training to be able assess and explain genetic risks, patient testing options, in addition to interpreting and describing genetic testing results in an understandable manner.

A genetic counselor will not require you to have any testing you do not want. Rather, a genetic counselor will provide you with complete information about testing options so you can make decisions that are right for you and your family.

Meet our Team:

All
  • All
  • Cardiology

La Pean Kirschner, Alison, MS, CGC
Position: Licensed, Certified Genetic Counselor
Specialties:
Cardiology

Sundstrom, Rachel, MS, CGC
Position: Licensed, Certified Genetic Counselor
Specialties:
Adult Genomic Medicine
Cardiology

More Information and Scheduling:

Referrals for HHT typically come from primary care providers or specialists treating complications of HHT.