DURHAM, N.C. -- Duke University Medical Center researchers have linked a
second gene to a rare bleeding disorder -- a discovery that offers insight
into how blood vessels form and heal in response to injury.
The finding links a previously identified human gene called activin receptor like kinase 1 (ALK1) to the disease hereditary hemorrhagic telangiectasia (HHT), a bleeding disorder that strikes 1 in 40,000 people. Geneticist Doug Marchuk, postdoctoral researcher David Johnson, the study's lead author, and colleagues from Duke and from six other research institutions reported the finding in the June issue of Nature Genetics. The study was funded by the National Institutes of Health, the American Heart Association, and the Baxter Foundation.
HHT, also known as Osler-Weber-Rendu disease, causes tiny veins to fuse into one large mass that can easily be ruptured, causing recurrent bleeding episodes in affected people. In some people, the disease is only a cosmetic problem with tiny red blotches forming on skin or recurring nose bleeds. Others suffer migraine headaches or lesions in the lung or brain that can lead to fatal strokes or aneurysms.
"By studying these genes for rare disorders, we are hoping to open a window into how the body's vascular system operates," Marchuk, assistant professor of genetics, said in an interview. "People often ask, why study genes for a rare disease? First, the disease may be rare, but the genes aren't rare. Everyone has these genes, and we would like to know how they operate normally so we can understand what can go wrong. Second, when it's your family with the disease, it is very important. We would like to be able to offer some hope to these families."
The protein encoded by the ALK1 gene appears to be made almost exclusively in the cells that line blood vessels. While researchers aren't sure of its function, it appears to interact with the potent growth factor, transforming growth factor
Contact: Karyn Hede George