The study was carried out on Amish population
One in five white people carries a gene fault which could raise their risk of high blood pressure, research suggests.
The STK39 gene variant was found after scanning the entire genetic code of hundreds of people in the US and Europe.
Those with the variant had raised blood pressure compared with those carrying other versions.
The US research was published in the Proceedings of the National Academy of Sciences.
High blood pressure, also called hypertension, is important because, over time, it can increase the chances of heart problems, strokes and kidney failure.
It is thought that one in four people living in western countries has high blood pressure, often undiagnosed.
Scientists looking for genetic vulnerabilities to the condition have explored dozens of possible genes, but STK39 has emerged as a front runner following the University of Maryland School of Medicine study.
The researchers concentrated their efforts on 542 members of the Amish community in Pennsylvania, looking at their entire genetic make-up while testing their blood pressure.
When this linked variants of the STK39 gene to high blood pressure, it made sense - the gene produces a protein which controls how the kidneys process salt - a key factor in changing blood pressure.
The result was reproduced when other groups Caucasian volunteers were tested, and the researchers estimated that 20% from this ethnic group carried it.
Dr Yen-Pei Christy Chang, one of the researchers, said: "This discovery has great potential for enhancing our ability to tailor treatments to the individual - what we call personalised medicine."
However, he added: "Hypertension is a very complex condition, with numerous other genetic, environmental and lifestyle factors involved.
"The STK39 gene is only one important piece of the puzzle."
Professor Alan Shuldiner, also from the University of Maryland, said: "With this new scanning approach, we are able to uncover genes that have previously eluded us."
Mike Rich, the executive director of the Blood Pressure Association, described the research as "interesting".
"It may help us identify those individuals who may be more prone to hypertension," he said.
"However, there are already indicators which can help us determine who is more likely to develop the condition, such as a family history of hypertension, heart disease, stroke, and poor diet and lack of exercise.
"The things you learn from your parents in terms of lifestyle and habits will probably have as much effect on your chances of developing hypertension as the genes they pass down to you."
Professor Mark Caulfield, a researcher in the genetics of hypertension from Queen Mary's, University of London, said the evidence pointed towards many different genes each having a small effect on blood pressure.