DNA Tests for Clotting Disorder Approved
FDA Approves Lab Tests for Genetic Clotting Risk, FDA Press Release, Dec 17 2003.
"[The FDA] today approved the first DNA-based laboratory tests for an inherited disorder. The new tests, for blood clotting abnormalities, represent a significant advance in technology. FDA has cleared other genetic tests in the past, but none was DNA-based.
The new tests will enable clinical laboratories to identify people who have an increased risk of developing blood clots in the veins of their legs and elsewhere because of hereditary abnormalities in two proteins involved in blood clotting. Five to ten percent of all Americans have at least one of these genetic abnormalities. If untreated, blood clots can cause death….
To perform the test, DNA sequences from a person’s blood are amplified using Polymerase Chain Reaction…A fluorescent tag then binds to the amplified DNA and is used to measure the presence or absence of the clotting mutation."
The diagnostic tests are for Factor V Leiden Thrombophilia and Prothrombin G20210A Thrombophilia. Here is another description of Factor V Leiden by the American Heart Assoc, in pdf; a more resources at the KU Genetics Education Center.