If you or someone in your family has been diagnosed with hemophilia or another bleeding disorder, meeting with a genetic counselor is key. Genetic testing enables you to collect valuable information that can help guide family decisions and empower you, your loved ones and future generations.
Genetic counselors often work with parents of an affected newborn or with women who want to know if they carry a genetic mutation that they could pass on to their babies. They also meet with affected adult men who get tested to help their daughters or sisters find out if they are carriers.
Here’s what to expect from a visit with your genetic counselor:
1. Pretest Consultation
The genetic counselor will spend about 30 minutes to an hour reviewing the affected person’s personal and family history of bleeding. He or she will ask about family medical history going back to the affected person’s grandparents or great-grandparents. The counselor will also talk to the affected person and his or her family about the benefits and limitations of genetic testing and what the possible outcomes of the test may mean to the family.
2. Blood Sample
Before this meeting, a hematologist will have pinpointed which bleeding disorder the test will target—hemophilia, von Willebrand disease or another rare disorder, such as factor V deficiency. Usually this is done by testing a blood sample from a family member known to have a bleeding disorder. This can identify the specific mutation causing the disorder; genetic testing locates the mutation in nearly 98% to 99% of people with hemophilia A or B, according to the National Human Genome Research Institute. Other family members wanting to be tested will then be checked for that mutation.
3. Discussing the Results
Once the blood test results come back, which is typically in two to three weeks, a genetic counselor will meet with the patient and his or her family to interpret and explain the results. This discussion may include considerations for family members (such as whether sisters or daughters may want to be tested for carrier status) and instructions on getting the right medical care.
For example, if a pregnant woman knows that she is a carrier, her doctor can take extra steps during delivery, including having factor on hand during the birth to prevent hemorrhaging, a common risk for women and affected newborns.
Genetic counselors can also help patients and their families find resources and support groups.