Hemophilia Carrier Fact Sheet

Important information for carriers of hemophilia

If you are pregnant or planning a pregnancy and there is hemophilia in your family, there are some important facts you should know:

• Knowing your chance to have a child with hemophilia is important medical information for you, your child and your physician.
• There is testing available to better define your chance of having a child with hemophilia.
• Prenatal testing may be available to test the baby during your pregnancy.

Hemophilia A (factor VIII deficiency) and hemophilia B (factor IX deficiency) are bleeding disorders caused by an abnormality in one of the clotting factors. Both types of hemophilia are inherited as X–linked recessive conditions. They are called “X–linked” because the genes for factor VIII and IX are located on the X chromosome. Chromosomes are in each of our cells and contain all of our genetic information. Chromosomes are very similar between males and females, except females have two X chromosomes while males have an X and a Y. Thus, females normally have two copies of clotting factor VIII and IX genes and males have only one copy. When there is an alteration or change in the factor VIII or factor IX gene, a male will have hemophilia. A female with an alteration will be a carrier of hemophilia.

Testing is available to find out whether a female who has hemophilia in her family is a carrier. Genetic testing is the most accurate method of carrier testing. It involves obtaining a blood sample to look for the specific gene alteration causing hemophilia in a family. Testing for carrier status with factor levels does not rule out carrier status. If you were tested by factor levels, you may have received inaccurate information. Finding out if you are a carrier provides important medical information for you and your children. Carrier testing may help you make family planning decisions, allows for prenatal diagnosis if desired, and may indicate precautions to be taken when your child is born for both you and your baby. Therefore, if you are currently pregnant or planning to have children, it is important to find out more about your risks and the availability of testing.

Steps you should take to find out about carrier testing:

• 1. Talk with your physician and arrange to meet with a genetic counselor to discuss carrier testing and your options.
• 2. Contact the Indiana Hemophilia & Thrombosis Center Inc. (IHTC) at (317) 871–0000 or toll–free at (877) 256-8837 to speak to the center’s genetic counselor.
• 3. Talk with your family to find out what type of hemophilia (factor VIII or factor IX) is present, the severity (mild, moderate or severe) and whether anyone has had genetic testing done. 4. If you are found to be a carrier for hemophilia or there is a chance you are a carrier, difficult delivery (notably, suction apparatus or use of high forceps) should be avoided and a male baby should be tested for hemophilia at birth through cord blood testing. Cord blood testing instructions and kits are available through the center. Circumcision should be delayed until the baby boy’s results are known.