Common Gene Glitch May Up Stroke Risk
Study Shows 2 to 3 Times Higher Stroke Risk Among Those With Mutation
March 26, 2007 -- A common genetic mutation may make people two to three times more likely to have a stroke.
Danish doctors report that news in Neurology.
The researchers include Borge Nordestgaard, MD, DMSc, who works in the clinical biochemistry department at Denmark's Herlev University.
Nordestgaard's team studied more than 9,100 Danish adults for 24 years.
First, researchers screened participants' HFE gene. Certain mutations in that gene cause hereditary hemochromatosis, a disease in which too much iron builds up in the organs.
Specifically, the doctors looked for the H63D mutation of the HFE gene -- a mutation linked to hereditary hemochromatosis.
The study shows about 2% of the participants had two copies of the H63D mutation, meaning the mutation would affect the person.
During the 24-year follow-up, 504 participants developed cerebrovascular disease, which affects brain-related blood vessels. And 393 of that number had an ischemic stroke, in which a clot blocks blood flow in the brain.
People who had two copies of the H63D mutation were two to three times more likely to develop ischemic stroke, even after considering other risk factors including age, sex, and BMI (body mass index, used to indicate overweight and obesity).
The study doesn't include cases of bleeding (hemorrhagic) strokes, which are less common than ischemic strokes.
Carotid Artery Findings
The researchers separately studied 701 Danish adults diagnosed with carotid artery atherosclerosis, or hardening of the arteries that run up either side of the neck and carry blood to the brain.
These patients also took gene tests, but the findings showed no link between the H63D mutation and carotid artery atherosclerosis.
The researchers call for more studies to learn how the H63D mutation affects stroke risk.