Hemophilia is a rare genetic bleeding disorder that almost always occurs in males. A person has hemophilia when he or she inherits problems with certain blood-clotting factors, making them unable to work properly. Blood-clotting factors are needed to help stop bleeding after a cut or injury and to prevent spontaneous bleeding. The hemophilia gene can contain many different errors, leading to different degrees of abnormality in the amount of clotting factor produced.
Haemophilia is an inherited life-long blood disorder in which blood-clotting time is prolonged for even minor injures and can cause spontaneous bleeding into joints and muscles for severely affected patients. It is found mostly in males, but inherited from female carriers. About 6500 people are affected with haemophilia in the United Kingdom.
Causes of Hemophilia
A male who has the abnormal gene on his X chromosome will have hemophilia. A female must have the abnormal gene on both of her X chromosomes to have hemophilia; this is very rare.
The transmission of this gene to offspring accounts for 70% of the cases of hemophilia. The remaining 30% occur from spontaneous changes in genes responsible for causing hemophilia.
Even hemorrhages in the brain often have no apparent cause. Brain hemorrhages are the leading cause of death from bleeding in hemophilia. Therefore it is important to recognize the symptoms of a brain hemorrhage very quickly.
If the father has hemophilia, but the mother does not carry the gene, then none of the sons will have the disease, because they get their one normal X from their mother, but all of the daughters will be carriers because they receive one normal X chromosome from their mother and one abnormal X chromosome from the father.
Men and women each have 23 pairs of chromosomes (pronounced: kro-muh-soamz). Women have two X chromosomes; men have one X and one Y chromosome. Hemophilia is an X-linked genetic disorder, which means that it's passed from mother to son on the X chromosome. If the mother carries the gene for hemophilia on one of her X chromosomes, each of her sons will have a 50% chance of having hemophilia.
Hemophilia is an inherited disorder that almost exclusively affects men. Women rarely have the disease but are the carriers who can pass the condition to their male children.
Symptoms of Hemophilia
Joint pain and swelling, frequently in the knees and elbows. Heavy bleeding or bleeding that lasts a long time, from an accident or other injury. The start of bleeding may be delayed.
In about 30% of cases there is no family history of haemophilia. These cases are the result of the gene responsible for producing factor VIII or IX mutating spontaneously, either in a man's sperm or a woman's egg. A mutated gene is often defective, so if a sperm or egg with the mutated gene is fertilised, the child may have haemophilia.
The most common bleeding problem a person with severe haemophilia has is bleeding into a joint (haemarthrosis), often without an injury. Bleeding usually occurs in one joint at a time. Bleeding may develop in any joint, but knees, elbows, and ankles are most commonly affected. Sometimes one particular joint, called a target joint, will tend to bleed most often. Another common symptom of haemophilia is bleeding into a muscle (haematoma), which can be mild or severe.
