How is Haemophillia contracted?

Haemophilia is mostly a genetic disease, males normally only have the symptoms and the women just carry it, very rarely receiving the symptoms. Haemophilia is passed through the X chromosome. When a father has the Haemophilia gene, none of the son's will have it but all the daughters will carry it. If a mother has the gene, there is a 50% chance that her sons will have haemophilia and a 50% chance her daughters will carry the gene. Although 1/3 people that are affected by haemophilia have no family history of the disease. This is  known as acquired haemophilia, this is when the persons immune system develops antibodies against one of their body’s own clotting factors and results in a reduced factor level in their blood. This normally occurs in older people and can equally effect men and women.