Scientists have taken a step forward in their efforts to find out why some people develop high blood pressure.
One in five Britons suffer from high blood pressure
British researchers have backed up previous studies which have suggested that the condition can be caused by faulty genes.
They have identified four areas of the human genome that may contain genes that increase a person's chances of developing the condition.
People with high blood pressure or hypertension are at higher risk of having a stroke or heart attack, and can suffer other health problems. The condition affects one in five people living in Britain.
This latest research was carried out by a team of scientists from universities across Britain as part of the Medical Research Council's British Genetic of Hypertension (BRIGHT) Study.
They carried out tests on 3,599 people from nearly 1,600 families where at least two siblings suffered from very high blood pressure.
There is clearly a huge amount of work to be done to refine this search
DNA tests showed many of these people shared a high number of the same genes. The researchers found that these genes were located on four chromosomes.
The researchers said the findings meant scientists were now a step closer to being able to identify the specific genes that may trigger high blood pressure.
Such a discovery could pave the way for new ways of diagnosing and treating the condition.
Dr John Webster, a consultant physician at Aberdeen Royal Infirmary and one of those involved in the study, acknowledged that much more work is needed before this point is reached.
"None of these results are of any value yet to individual families.
"There is clearly a huge amount of work to be done to refine this search and even more to translate it into any useful diagnostic test or treatment but it is a major first step," he said.
"The BRIGHT study results enable us to home in on areas of the human genome that may contain important genes for this common disorder.
"At this time, we do not know the precise genetic factors."
He added: "By understanding the genes which predispose people to common disorders such as hypertension, we may gain insights into the mechanisms behind the condition, possibly discover new medications and improve control of this major cause of heart disease and stroke."
Belinda Linder, head of medical information at the British Heart Foundation, welcomed the study.
"This could open the possibility of new methods to diagnose and better control hypertension.
"This study has started to unravel the complicated genetic picture of hypertension."