Mayo Clinic researchers looking for genes that increase stroke risk

Friday, February 23, 2001

JACKSONVILLE, Fla., Feb. 23, 2001 — Researchers at Mayo Clinic in Jacksonville, Fla., are recruiting siblings who have suffered a stroke for a new study. The study is the first one designed to screen the entire set of human genes for regions that increase ischemic stroke risk. Hypertension, diabetes and smoking increase a person's risk of suffering a stroke. Researchers believe inheritance of specific stroke risk genes may explain why stroke also tends to run in families.

A stroke, or "brain attack," happens when a blood vessel in the brain becomes blocked or bursts. If blockage causes a stroke, it is called ischemic. If a ruptured blood vessel causes the stroke, it is called hemorrhagic. The resulting loss of blood flow causes brain cells to die, and victims suffer impairment of brain function or even death. More than 750, 000 Americans suffer a stroke each year, and 150,000 of them die.

Dr. Thomas Brott, a Mayo Clinic neurologist, is one of the investigators for the multicenter, nationwide study called "Siblings With Ischemic Stroke Study" or SWISS. These investigators, supported by a grant from the National Institute of Neurological Disorders and Stroke, hope to enroll at least 300 pairs of siblings into the study over the next few years.

A single missing or defective gene causes some diseases such as sickle cell disease and Duchenne muscular dystrophy. However, stroke is not as genetically straightforward. Brott suggests a number of genes play a roll in increasing an individual's risk of stroke.

Once these risk genes are identified, Brott says therapies to reduce stroke risk might be developed that will target specific genetic compositions. "We have different treatments to prevent stroke," Brott says. "It may be that one treatment is particularly good for one particular genetic makeup, and another treatment is good for another genetic makeup. This may explain our studies which show mixed effects of our medicine to treat stroke when we treat everyone the same way."

To qualify for the study, a person has to have had an ischemic stroke within the preceding six months, and he or she must have a living sibling who has also had a stroke in the past. Both must be willing to provide a blood sample and release their medical records to the study investigators who will keep all genetic, demographic and medical information confidential and anonymous.

Those interested who think they may qualify for the study, should contact Kristin Cornwell, study coordinator, at the Mayo Physician Alliance for Clinical Trials, by calling 1-800-541-5815, or via e-mail sent to cornwell.kristin@mayo.edu.

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Media contact: Erik Kaldor 904-953-2299 kaldor.erik@mayo.edu

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