DNA Testing for HHT Vascular Disorder Now Available in United States: Could Prevent Stroke

New Haven, CT - The Hereditary Hemorrhagic Telangiectasia (HHT) Foundation International announced today the availability of a diagnostic blood test for this genetic vascular disorder that effects the health of at least 60,000 Americans and accounts for many unexplained nosebleeds, brain and lung life threatening strokes, and hemorrhages.
For the first time, three North American laboratories will offer the test to patients with symptoms of HHT, to determine if they and their family members carry mutations, or changes, in one of two genes that cause the disorder. Laboratories now testing for the Endoglin and ALK-1 genes are ARUP Laboratories (Salt Lake City, Utah), the University of Pennsylvania, and HHT Solutions of Toronto.
"The availability of this test will allow identification of infants and children with HHT before life threatening brain or lung hemorrhage occurs,' said Dr. Robert White, interventional radiologist at Yale Medical School and Chair of the HHT Scientific and Medical Board. White has been a pioneer and leader in the battle to understand, identify, and treat HHT.
Since HHT is an autosomal dominant gene disorder, children from one affected parent have a 50-50 chance of inheriting the disease. However, many children and adults with the disorder remain unaware of it until a crisis develops. The most common symptom of HHT is nosebleeds. However, if the disease is identified early on, the more serious symptoms of the disorder, brain and lung AVM's, may be detected by modern imaging techniques and treated.
"This diagnostic test will enable families to identify who does and does not have the disorder. Thus, screening and treatment, if necessary, of lung and brain arteriovenous malformations in children may be performed before stroke or hemorrhage occur' said Dr. White. "In the past, otherwise healthy and often young individuals have died of unexplained stroke or brain or lung hemorrhage, and may have been HHT victims without knowing it.'
This development had been anticipated for seven years, since the identification of the genes involved in 1994-96 by teams from Britain, Canada, Scotland, and the United States. Researchers in North Carolina and Toronto subsequently developed the clinical laboratory test now available. "Projected research on HHT symptoms may also have broad and vital implications for many other vascular conditions affecting millions of individuals,' commented Dr. Alan Guttmacher, Deputy Director of the National Human Genome Research Institute of the National Institutes of Health and long time HHT researcher.
Thousands of patients, who have been seen at 17 HHT Centers of Excellence around the world, are now expected to begin taking advantage of this new diagnostic blood test. Asymptomatic members of their families can be tested as well. One issue that remains to be understood is the insurance coverage available for this genetic test, particularly for asymptomatic family members. With the hoped for passage of the Genetic Non-Discrimination Act recently approved by a 95-0 vote by the U.S. Senate and now before the U.S. House of Representatives, patients testing positive for the genes should be protected from possible discrimination on the part of health insurers or employers.
The Foundation is currently undertaking a $10 million fundraising campaign to advance research efforts into the causes and cures for nosebleeds, gastrointestinal bleeding, and brain and lung aneurysms. Research results may have far reaching implications beyond the confines of those affected by HHT.
With the availability of this test at three North American HHT Centers, many more cases of Hereditary Hemorrhagic Telangiectasia are expected to be diagnosed, family patterns established, and the most serious consequences of the disorder prevented. Genetic counseling, treatment and general information about HHT will also be available at the 17 HHT Centers of Excellence around the world. For more information, contact Marianne Clancy, Executive Director of the HHT Foundation International, 1-800-448-6389 or visit www.hht.org.


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