Hemophilia
Diagnosis

The diagnosis of hemophilia is made by blood tests to determine if clotting factors are missing or at low levels, and which ones are causing the problem. If you have a family history of hemophilia, it is important to tell your child's doctors which clotting factor your relatives are missing, since your child will be missing the same one.

If you know you are a carrier, the diagnosis of hemophilia can be made in your newborn soon after birth. Tests to determine if your baby has hemophilia can be run on blood obtained from the umbilical cord or drawn from the newborn's vein. You will be advised to delay some procedures, such as circumcision, until after you learn whether your child has hemophilia.

Some families with a history of hemophilia may want to request prenatal testing, or testing before birth. This testing can be done early in pregnancy, allowing your family to make informed decisions and preparations. UCSF Children's Hospital has genetic counselors who are available to help you make family planning decisions and arrange for prenatal testing, if desired.

If you are pregnant and think you could be a carrier, or if you have a child diagnosed with hemophilia and you are expecting another child, it is important that you tell your obstetrician that you are at risk for having a child with hemophilia. There are three ways to test if you are a carrier:

• Family Tree — Review your family tree. If you have a son with hemophilia and have another son, brother, father, uncle, cousin or grandfather with the disorder, then you are a carrier. No additional tests are needed.



• Clotting Factor — Measure clotting factor level in your blood. If it is below 50 percent of normal, you probably are a carrier and have mild hemophilia. If the clotting factor level is above 50 percent, you still may be a carrier, since other conditions can elevate the factor level. Another test may be necessary.



• DNA Test — Conduct a DNA test to look for the mutation that caused hemophilia in your son or another relative. It is necessary to obtain samples of blood from your son or relative with hemophilia.

Reviewed by health care specialists at UCSF Children's Hospital.
Last updated February 4, 2010

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