If I have a family member who has had a blood clot or thrombophilia, but I have never had a blood clot, should I be tested for thrombophilia?

If the family member with a blood clot does not have an inherited thrombophilia, then it is less likely that the risk of a blood clot would be increased in other members of the family. In such a case, testing for thrombophilia would not be indicated. If it is not known whether the family member has an inherited (versus acquired) thrombophilia, then the healthcare provider would essentially have to perform a broad panel of tests to evaluate any unaffected family members. Without knowing which specific thrombophilia may or may not be present in the family member who had the blood clot, the results of a broad panel of tests may not be useful to other family members. Testing for thrombophilia, therefore, is not generally recommended in this situation.

If one of your first-degree relatives (sibling, child, or parent) has been diagnosed with an inherited thrombophilia, then you might want to discuss with your healthcare provider the option of being tested. This discussion should include which specific tests would be done, what the likelihood of a positive test result would be, what a positive result would mean for you and your family, and, if a test is positive, what changes in lifestyle or treatments you should consider.

For people who test positive, additional issues would likely need to be discussed after the results are obtained. In addition, consultation with a genetic counselor might be appropriate.

A genetic counselor can assess risks based on family history, provide education about the condition in question, and describe the risks, benefits, and limitations of testing.

Whether an individual decides to pursue testing is a personal choice. Some people decide to undergo testing because the results may help them make certain lifestyle changes or seek treatment. For example, a woman who tests positive for an inherited thrombophilia might choose to avoid oral contraceptives or estrogen therapy. Some people who test positive might choose to take an aspirin a day, although studies have not proved that this measure will prevent a venous blood clot (See Question 91). For some individuals, simply knowing that they have a negative test result might provide peace of mind.

Other people may choose to decline testing because the information may not be useful to them. As with any inherited or genetic condition, there may be some concern about potential health or life insurance discrimination. The risk of being denied or having to pay higher premiums for coverage is not well regulated.

If you are interested in being tested, you should speak to your primary care provider or seek out a genetic counselor who is knowledgeable about bleeding and clotting disorders.