A normal factor VIII or factor IX level test will not tell women or girls whether they carry the altered gene causing haemophilia. Some women or girls may have normal factor levels, but still carry the gene.
A common time for testing whether a girl or woman carries the gene is when she reaches childbearing age and can understand the process and implications fully and make the decision for herself. Finding out whether she carries the gene is a process which will take time, sometimes many months. This may involve:
- Discussion with a haemophilia specialist and/or genetic counsellor
- Weighing up the pros and cons of genetic testing with advice and support from specialists, counsellors and other experts - for example, the role of genetic testing in understanding her bleeding disorder; its effect on her perception of herself and on her relationships; her personal understanding of what it’s like to have haemophilia; the impact on children and other family members; her personal religious and cultural beliefs; future disclosure obligations and implications for life or income protection insurance; any costs involved; and other issues relevant to her personal situation
- Looking at the family tree to identify other family members who may carry the gene
- 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 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 Centre can help with information and advice about genetic testing and can provide a referral to a genetic counsellor, if needed. Women, their partner, parents or family can talk to the Haemophilia Centre or genetic counsellor individually or together prior to testing and many find it helpful.
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.