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
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Contact: Karyn Hede George
georg016@mc.duke.edu
919-660-1301
Duke University
31-May-1996