Why do women and girls have genetic testing for haemophilia?
A normal factor VIII or factor IX level test will not tell females whether they carry the gene alteration causing haemophilia. Some females may have normal factor levels, but still carry the gene alteration.
In genetics, all females who have the gene alteration causing haemophilia are called ‘carriers’.
A common time for testing whether a girl or woman is a carrier is when she reaches childbearing age and can understand what will happen with testing and what it means and make the decision for herself.
Finding out whether she has the gene alteration is a process which will take time, sometimes many months. This may involve:
- Discussion with a haemophilia team specialist and/or genetic counsellor
- Weighing up the pros and cons of genetic testing with advice and support from specialists, counsellors and other experts
- Looking at the family tree to identify other family members who may have the gene alteration
- Blood tests for other affected family members (eg, a man with haemophilia) to identify the particular genetic mutation causing haemophilia in her family
- Blood tests for the woman or girl to see if she has the same family genetic mutation
Many people find that undertaking these tests gives them a lot to think about. The Haemophilia Treatment Centre can help with information and advice about genetic testing and can provide a referral to a genetic counsellor, if needed. Women, their partner, family or parents of girls can talk to the Haemophilia Treatment Centre or genetic counsellor individually or together prior to testing.
Where can I have a genetic test?
Usually your state or territory clinical genetics service or your Haemophilia Treatment Centre (HTC) will undertake your genetic testing. They can also provide genetic counselling
They will use a specialist laboratory to analyse the results. You will need a referral.
If you are speaking to your general practitioner (GP) about genetic testing, ask them to refer you to an HTC for diagnosis. If your GP is reluctant to refer you for genetic testing, you can request a referral to a clinical genetics service to discuss your options.
What if I change my mind?
If a person starts exploring genetic testing but decides against it, there is no obligation to complete the process.
For more information about genetic testing, see the Policies and Position Statements on the Human Genetics Society of Australasia web site
For more information about testing for haemophilia before birth, read the section in Pregnancy.
For more information about genetic testing for haemophilia,
Or read our booklets:
A guide to haemophilia testing in women and girls (genetic testing and factor level testing)
More comprehensive version