Writing in PLOS ONE they say the gene fault may encourage the formation of blood clots - the ultimate cause of most heart attacks and strokes. Scientists hope gene tests may help doctors one day to pinpoint individuals more likely to suffer these conditions.
But experts say lifestyle factors such as smoking and exercise have the greatest influence on risk.
Hypertension Journal 2014
Around one in 10 people in the Caucasian population carries this variation of the gene, named PIA2. And researchers from King's College London reviewed more than 80 studies involving about 50, people - the largest analysis of this genetic fault to date.
Threat to unders They found individuals with PIA2 were world journal of hypertension impact factor likely to have a stroke - caused by a blood clot blocking blood supply ad norm hipotenzió magas vérnyomás the brain - than those without the gene.
But how significant this increase is depends on an individual's baseline risk - influenced by factors such as smoking, diet, weight and exercise, the scientists say.
In a second study published in the same journal, the scientists show PIA2 is also linked to an increased risk of heart attacks in people under More research is needed to see whether this holds true for the whole population, they say.
Aboutpeople have a stroke in the UK each year and more thanheart attacks are recorded annually.
Both thrombotic strokes the most common kind and heart attacks are caused by blockage of blood vessels in the heart and brain - ultimately through the formation of clots.
Platelets help trigger the formation of clots to stop bleeding after injury. But scientists say carrying the gene may render them overactive.
They caution that overall the genes play a smaller role in risk than more established factors, such as high blood pressure and obesity. But developing a genetic test could help predict people at highest risk, allowing doctors to suggest more potent medication or lifestyle changes, they say.
In patients with PAH, the concentrations of prostacyclins are reduced in the pulmonary circulation and this phenomenon leads to the imbalance between the vasoconstrictor and vasodilator forces in the pulmonary circulation.
Prof Albert Ferro, of King's College London, who led the research, told the BBC: "We would now need to validate this test and see how useful it is in the clinical world. Regular exercise, eating a balanced diet and stopping smoking can be important steps to significantly reduce your stroke risk.