Haemophilia is caused by an alteration in the gene making factor VIII (8) or IX (9)
Men and women can carry the genetic alteration causing haemophilia and pass it on to their children
Many women who carry the gene do not have bleeding symptoms
Some women who carry the gene can have a bleeding tendency
Symptoms in women include bruising easily, heavy or long menstrual periods, bleeding for a long time after childbirth, surgery, medical procedures, dental extractions, injuries or accidents
If a female’s factor levels fall in the range for mild haemophilia (5-40% of normal clotting factor), she may also be referred to as having "mild haemophilia".
In very rare cases, some girls or women have particularly low factor levels causing them to have moderate or severe haemophilia, and they may also have joint or muscle bleeds.
