GENEVA -- The World Health Organization said Wednesday it approved the first international standard for a human genetic test to help laboratories improve the accuracy and quality of their results.

The standard - which will help identify testing errors - is for a commonly used procedure that identifies a genetic predisposition to thrombosis, or blood clots, a potentially life-threatening condition.

Standards could also eventually be introduced for other genetic disorders, such as cystic fibrosis and muscular dystrophy.

"Establishment of the first international standard for a genetic test is an important milestone," said Dr. David Wood, WHO's chief of quality assurance and safety of biologicals. "Genetic testing procedures are playing a vital and growing part in clinical medicine."

It is estimated that more than 700,000 genetic tests were performed in 2002 in the European Union alone. WHO said that millions of tests are probably being carried out globally each year.

The standard will help ensure that genetic tests are done to a high level of accuracy, WHO spokeswoman Melinda Henry told The Associated Press.

"The test determines if the person has a gene which would predispose them to the illness," she explained. "The added information (gained from using the standard) may have implications for the patient - what medicine they have to take - and to family members, whether they are predisposed to the illness."

The new standard relates to the testing of patients for a genetic mutation called Factor V Leiden, which causes a defect in the natural anticoagulation system and is involved in 20-40 percent of all cases of venous thrombosis.

The test to determine whether the Factor V Leiden mutation is present is one of the most common genetic tests carried out in clinical laboratories. The mutation can dramatically increase the risk of contracting thrombosis by up to 80 times, depending on whether the individual has one of two copies of the gene.

"Setting standards is particularly critical as genetic testing has expanded to more and more laboratories throughout the world," the agency explained. "Genetic testing must be done consistently in all laboratories around the world and to high-quality standards in order to give confidence in the results."

WHO said it will likely approve standards for other genetic tests in the future and that increasing use of standards "will enable prevention and early treatment of genetic disorders, improving quality of life."