The family had no idea then that the nosebleeds were a clue they were passing down a potentially deadly genetic blood-vessel disorder called hereditary hemorrhagic telangiectasia, or HHT.

The disorder is often accompanied by an abnormal tangle of blood vessels in a lung or in the brain, the condition that recently required South Dakota Sen. Tim Johnson to undergo emergency brain surgery. Such an arteriovenous malformation, or AVM, can cause a stroke by hemorrhaging.

Because AVM and HHT are linked, health professionals and others are hoping Johnson's plight will result in wider knowledge and diagnoses of both.

Four of Abbott's six children inherited HHT, and two have died.

Of 20 grandchildren, two died of complications from the disorder and four are living with HHT.

"Sometimes it's very hard to talk about what has happened to my family, but we need to educate doctors and the public about HHT and AVM," the 69-year-old Provo man said. "Having an AVM is a time bomb ticking in your body. HHT is not that uncommon, but it's rare enough that many doctors don't recognize it."

Utah is a hotbed for research and treatment because University Health Care is one of only eight HHT centers nationwide that specialize in the disorder. With early diagnosis, screening and treatment, patients can prevent a stroke.

Most people are unaware they have an AVM, but if they suffer from one, they should be tested for HHT.

"Anyone who is diagnosed with an AVM of the brain, lungs or liver should be asked by their doctor whether or not they or any relatives have recurring nosebleeds," said Jamie McDonald, a licensed genetic counselor who is co-director of the University Health Care's HHT Center of Excellence.

"If the answer is yes, the individual should be examined for very small, often pinpoint-sized red spots known as telangiectasia," she said.

A telangiectasia is a small version of an AVM found primarily on the lips and hands of people with HHT. The disorder is frequently undiagnosed because most primary care physicians are not familiar with it.

In 2004, University Health Care's HHT Center began offering a DNA test to diagnose people at high risk of having the condition.

The clinic offers lung and brain screening for blood-vessel malformations and evaluates people for anemia. Until the genetic test, it was difficult to diagnose HHT in children and infants because the physical signs of the disorder don't become obvious until people reach their teens or adulthood - and even then, they often are undiagnosed.

"Even when someone presents with a brain AVM, like Senator Johnson, I can almost assure that his neurosurgeon . . . hasn't asked him in the family history if there are any signs of a brain AVM or nosebleeds," McDonald said. "Doctors need to ask the right questions about family history."

HHT is caused by a mutation in one of several genes. There is no way to prevent AVMs from occurring, but most can be treated once detected. Treatment varies depending on where they exist in the body.

For severe nosebleeds, doctors can try embolization - blocking off blood flow to abnormal blood vessels with a laser. If people bleed from the stomach or intestines, iron replacement therapy is recommended.

Removing lung AVMs often involves embolization in which a catheter is inserted into a vein in the groin and passed to the lung. Then the physician places a device in the artery to cut it off from the lung's circulation.

Surgery, embolization and radiation therapy, or a combination of the three, have successfully treated brain AVMs.

As president of the HHT Foundation International, Abbott recommends people with HHT be assessed at one of the country's HHT Treatment Centers of Excellence.

"The good news is there are some diseases that just get worse no matter what you do," Abbott said. "We are so fortunate in having a condition that is diagnosable and treatable."

Abbott's family did not learn about HHT's link to AVMs until one of his daughters had died of a stroke.

"If we could get the word out to doctors and the public, we could avoid these tragedies," Abbott said.

For more information, visit www.hht.org or call University Health Care's HHT Center of Excellence at 866-292-4HHT (866-292-4448).

chamilton@sltrib.com