HHT FAQs

The HHT Foundation International, Inc. does not provide medical advice, nor does the printing of these answers constitute medical advice. For professional advice consult your medical caregiver.

Can you recommend a doctor in my area who specializes in HHT?

Unfortunately, in most areas there are no physicians who specialize in HHT. We recommend that all people with HHT be evaluated at least once at one of the HHT Treatment Centers. HHT is a multi-organ disorder and the teams at these centers are able to diagnose and treat all aspects of the disorder. We can supply you with the locations and phone numbers of these HHT Centers. In your home town, we recommend that you find a physician who listens and is willing to learn new information and ask for outside expertise when faced with a patient with a rare disorder like HHT. Once you have been evaluated at one of the HHT Treatment Centers, they can work with your local doctor who can provide your ongoing care close to home.

My family physician is interested in getting information about taking care of a patient with HHT. Is there a standard protocol that should be followed?

Yes. We would be happy to send your physician our information package; call the HHT Foundation at 410-357-9932 with your physician's contact information. In the meantime, ask your doctor to review the resources available on our website.

Is there a blood test or DNA test available to diagnose HHT?

Yes, but it is important that a family member with confirmed HHT (based on clinical symptoms) be the person to act as the initial proband.  In order to decide whether genetic testing will be helpful in your family, it is usually necessary to be seen either at an HHT Center or a genetics clinic/department in your area.

If I have HHT, what is the chance a child of mine will have HHT?

Each child born to an HHT parent has a 50% chance of inheriting the HHT gene mutation. One copy of each gene is inherited from the father and the other copy from the mother. People with HHT have one normal copy of the HHT gene and one mutated copy. When a person with HHT has a child, he or she will either pass on the normal copy of the gene, or the copy with the mutation. A child who inherits the gene with the mutation will have HHT. A child who inherits the normal copy of the gene will not have inherited HHT. Therefore, each time a person with HHT has a child, there is a 1 in 2 chance (50%) that the child will have HHT.

Can HHT skip generations?

No, but sometimes it can look like it did. At the genetic level, you either have HHT or you don’t. There is no such thing as being a carrier of HHT (that term is reserved for genetic disorders that are recessive, not dominant like HHT). If a grandparent and grandchild both have HHT, it can safely be assumed that the "parent" in between the two also has HHT. However, remember that HHT can be EXTREMELY variable in its severity even within the same family. For example, some people with HHT get multiple nosebleeds per day and some only a couple per year. So occasionally is might look like HHT skipped a generation because the "parent" had such mild manifestations of HHT that they were not obvious.

What is the life expectancy of persons with HHT?

As long as the lung and brain malformations are treated, on average, the life expectancy of people with HHT is not significantly altered.

I've been told I have an AVM in an internal organ? What should I do?

In the last decade much new information has been learned and published in medical journals about the treatment of AVMs in internal organs of individuals with HHT. Unfortunately, the majority of physicians aren’t yet familiar with the most current treatment options and recommendations. If you have been told you have a "spot", a nodule or AVM from an x-ray, CT scan or MRI, you and/or your local physician should immediately contact one of the HHT Treatment Centers. The medical professionals at the HHT Treatment Centers are glad to talk to patients and physicians from around the world about when and how an AVM should be treated.

Can AVMs grow?

Many do not, but they can. Our best information about this is from observation of lung AVMs. They have been known to increase in size over time. The growth is usually quite slow, but can occasionally be more rapid such as during puberty or pregnancy, or when combined with certain heart valve problems.

My nosebleeds are mild. Does this mean that even if I do have HHT, I have a "mild" case?

Not necessarily. About 30-50% of people with HHT will have at least one AVM in the lungs and about 5-20% will have an AVM in the brain. There doesn't seem to be a correlation between the severity of the nosebleeds and what's "inside" the body. Since there is no way to predict who will have an AVM of the lung or brain, routine screening for everyone with HHT–regardless of the severity of nosebleeds- is the only way to detect their presence.

My father and I would both like to be screened for AVMs. How do we go about it?

We recommend that you call, or have your physician call, the nearest HHT Treatment Center, for recommendations about the most appropriate screening tests for your situation. Depending upon your insurance, history and preference, you can work with your family physician to get the screening done locally. Alternatively, the screening tests can be done at one of the HHT Centers.

How can I get to one of the HHT Treatment Centers?

It’s often easier than you think. Each of these Centers has someone who helps with referrals, insurance authorization, logistics and scheduling. Since HHT is a rare disorder, there will never be expertise in all cities and medical centers. Most of the patients seen at the Treatment Centers have made arrangements to travel from out of state because they believe it is a valuable use of time and money. Often it is not necessary to have more than one visit to an HHT Center. The evaluation and screening can usually be done in one day. After the Center has seen you for evaluation and/or treatment, they are able to advise your local doctor about your long-term care needs. There is simply no substitute for being evaluated at least once in your life by physicians who specialize in your disorder.

How can I afford to go to one of the HHT Centers?

Often, authorization for evaluation at one of the HHT Centers can be arranged with an insurance company so that it costs little to nothing more to be seen at one of these clinics with expertise, than it would in your local medical community. Insurance companies never pay for travel expenses, however. For individuals who are unable to afford the travel costs, there is a charitable organizations that fund travel expenses for people who must travel long-distance for specialized medical evaluation, diagnosis or treatment.

My mother has been diagnosed with HHT and also has heart failure. Could this be related to HHT?

Some people with HHT have abnormalities in the liver that can actually either cause or contribute to heart failure. The possibility of liver AVMs should be considered in a patient with HHT and high output heart failure, particularly if the heart failure occurs at a relatively young age. Currently, most of the treatments that have been successful in treating the telangiectasia and AVMs elsewhere in the body have proven dangerous when done on the liver. It is particularly important for someone with HHT not to have any treatments involving their liver without contacting an HHT Treatment Center first.

What ethnic groups are affected by HHT?

HHT is an "equal opportunity" disorder. It is not limited to, or found predominantly in, people of a particular ethnic background, as are some other genetic disorders.  HHT has been found on every continent.  The HHT Foundation has had requests for information from China, Greece, India, Japan, Peru, Russia, Norway, South Africa, to name just a few. Treatment centers have been formed in many countries.

Can a person with HHT donate blood?

Yes, as long as their hemoglobin or hematocrit is at an acceptable level.

I have HHT and two small children. When should they be tested for lung AVMs?

There are currently no standard guidelines for the screening and treatment of lung AVMs in children. Based on the fact that some children have had complications from lung AVMs, we do advocate screening for all children of a parent with HHT. This screening should start as a baby with pulse oximetry every two or three years. Though oximetry will not detect mildly or moderately decreased oxygen levels, it will detect severely decreased oxygen levels. It seems to be the children who have severely decreased oxygen levels who are at risk for complications. Also, if a child is complaining of shortness of breath when exercising, or is having a hard time keeping up in sports, they should additional testing for lung AVMs depending on the age. At the age of 12, all children with HHT should have the same screening for lung AVMs recommended for adults. Children can be safely treated with embolization.

What are the symptoms or signs of HHT in the gastrointestinal tract (stomach and intestines)?

Unexplained anemia or low blood count, traces of blood in the stool, (although people with nosebleeds may also have blood in the stool), black (like tar) stool in the absence of iron therapy, and in extreme cases, eliminating or vomiting blood.  But they rarely cause pain.

Can my child with HHT play sports?

Yes. There are very few instances in which someone with HHT needs to limit their activity.  Scuba diving is probably the one sport that individuals with HHT should avoid. Small lung AVMs may be present and cause "the bends".

Is pregnancy safe for someone with HHT?

Yes, as long as the pregnant woman has no untreated lung AVMs. We strongly recommend that all women known or suspected to have HHT be screened for lung and brain AVM prior to becoming pregnant, or during the early second trimester of pregnancy if a pregnancy is already in process. Serious complications, such as life-threatening bleeding and strokes, have occurred in pregnant women with HHT who had undetected and thus untreated lung AVMs.  Otherwise, serious HHT-related complications for the mother or baby are rare. Some women report that new skin telangiectases developed during their pregnancy and that their nosebleeds worsen. However, some women actually report an improvement in nosebleeds while pregnant.

It's been a while since my lung AVM was treated. Is there anything my doctor and I should be concerned about?

Follow-up evaluation at an HHT Treatment Center at regular intervals is recommended. Small AVMs in the lung, which were too small to embolize originally, may reach a size where they need to be blocked off (embolized).

What are telangiectases?

In the circulatory system, arteries take blood from the heart and distribute it to the tissues of the body via capillaries. Then the "used" blood is taken back to the heart via the veins. In HHT, some blood vessels are missing the capillaries, or the capillaries are a dilated and tangled jumble. This results in an artery and vein having a direct connection, which is not normal. These blood vessels that have missing or abnormal capillaries (telangiectases) can be fragile and rupture more easily than a normal blood vessel. Fortunately, most of the blood vessels in someone with HHT are perfectly normal.