Family doctor

OVERVIEW

• Haemophilia is a lifelong blood clotting disorder, able to be managed with treatment. It is hereditary(X-linked recessive) and most usually only males suffer the symptoms.
• Haemophilia is caused by lack of activity of blood clotting factors VIII or IX. Symptoms include bruising, internal bleeding at joints and bleeding following surgery and injury.
• 1 in 10,000 men have haemophilia A. 1 in 50,000 men have haemophilia B.
• Treatment involves using a replacement blood clotting factor and replacement of lost blood when necessary.
• It is a common myth that a sufferer of haemophilia bleeds profusely from even the smallest of cuts, and will bleed to death - clotting just takes longer.
• Haemophilics may suffer joint pain and deformities in the long-term.
• These days clotting products undergo a heat treatment which kills the HIV and Hepatitis B and C viruses, preventing transmission.
• Von Willebrand disorder is similar to haemophilia in as far as it affects the function of the blood platelets and is inherited, however symptoms affect both males and females.
• Most people with haemophilia receiving treatment lead relatively normal lives. Support groups can prove helpful.
• When planning a family, the condition can be detected in carrying females, and diagnosis before birth is possible.

What is haemophilia?

Haemophilia is a blood disorder where the blood does not clot normally. Haemophilia A is the most common form, caused by a deficiency of blood clotting factor VIII. Haemophilia B is due to a deficiency of blood clotting factor IX.

This is a life long condition with no known cure, although can be managed with treatment.

Haemophilia is an hereditary disorder. In almost all cases, it is males that suffer the condition, although it is passed on by both females and males carrying the gene.

Queen Victoria was a carrier of haemophilia A. It is also known as classical haemophilia and factor VIII deficiency haemophilia.

Haemophilia B is also known as Factor IX haemophilia, and Christmas disease after the first patient diagnosed with it.

Do the effects of haemophilia vary between people?

Symptoms vary, depending on the degree of severity suffered. The severity of the disease is measured by the level of activity of the blood clotting factors VIII and XI. Normal clotting factor activity ranges between 50-200%:

• Mild Haemophilia - clotting factor of 5-50%, bleeding usually only occurs during tooth extractions, surgery or severe accidents.
• Moderate Haemophilia - clotting factor of 2-5%, bleeding is usually related to some injury.
• Severe Haemophilia - clotting factor of 1% or less, spontaneous bleeding occurs in joints, muscles and tissue without injury.

What are the symptoms?

Symptoms vary depending on the severity of the case.

Severe cases become apparent at an early age. Bleeding is the most obvious symptom and may become apparent if circumcision is performed. Once an infant becomes mobile, injury and bruising may show up symptoms.

A mild case may go largely unnoticed unless surgery is performed or injury occurs.

Internal bleeding is the most usual symptom and generally goes unnoticed if the condition is not detected, unless pain in the joints follows.

As sufferers grow older, they seem to experience fewer bleeding episodes. This may be due to the care they learn to take, to prevent injury and bruising.

General symptoms may include:

• bruising
• spontaneous bleeding
• nose bleeds
• bleeding into joints, leading to pain and swelling
• bleeding of the gastrointestinal and urinary tracts
• blood in the urine or faeces
• prolonged bleeding from cuts, removal of a tooth and surgery.

It is a common myth that a sufferer of haemophilia bleeds profusely from even the smallest of cuts, and will bleed to death. Although a haemophiliac bleeds for longer than usual and may need to apply pressure to the cut, clotting does occur. Deeper wounds usually require application of a clotting factor to form a large enough clot to stem the flow.

How common is it?

Having a family history of bleeding and being male puts a person at risk of suffering this condition.

1 in 10,000 men have haemophilia A.

1 in 50,000 men have haemophilia B.

It is very rare for women to show symptoms of haemophilia.

Haemophilia is inherited, however between 25-30% of cases occur in families with no history of the disorder.  

How is it inherited?

The gene for haemophilia A and B is carried on the X sex chromosome. The X and Y chromosomes determine sex of a person. Women have two X chromosomes, while men have an X and a Y chromosome.

Haemophilia is known as a recessive trait. In the case of haemophilia, this means the condition will only occur if the matched sex chromosomes (XX or XY) do not supply information to tell the body to produce the clotting factors VIII or XI.

As the Y chromosome does not supply information to the body on how to produce clotting factors, men are at risk of having this condition show symptoms if they inherit a defective X chromosome.

Women have two X chromosomes, so the dominant non-defective X chromosome supplies information to the body to produce clotting factors to compensate for the defective X. Although women very rarely show symptoms, they can still carry the defective X chromosome.

In the case where a mother is not a carrier but the father has haemophilia, he will pass the condition onto all his daughters, but not his sons. They will inherit their mother's non-defective dominant X chromosome.

In the case where the father does not suffer haemophilia but the mother carries defective X chromosome, there is a 50/50 chance of each son or daughter inheriting the defective gene.

In summary, the likelihood of inheriting the condition from a father suffering the condition is definite for female children and nil for male children(unless the mother is a carrier). The chance of inheriting the condition from a mother carrying the condition is 50/50 for both male and female children.

How is it diagnosed?

If the suspected sufferer of haemophilia is the first in a family to show a bleeding disorder, coagulation studies of their blood involving many tests will take place.

When it is known there is a history of haemophilia in the family, less testing is required to diagnose the condition.

Detection of haemophilia before birth is possible, using a variety of tests including amniocentesis and genetic testing.

How is haemophilia treated?

Treatment involves using a replacement blood clotting factor and replacement of lost blood when necessary.

For both haemophilia A and B, concentrates of the appropriate clotting factor is infused. The amount used depends on the severity and site of the bleeding and the patient's age and size. People with haemophilia and their families are taught how to administer the clotting factors at first sight of bleeding, to avoid crisis situations.

In some cases, an infusion may be given to a patient prior to surgery or tooth extraction.

Mild cases of haemophilia A may be treated with factors known as cryoprecipitate or DDAVP. These prompt the release of the body's own stores of factor VIII from the blood vessel linings.

What complications are associated with haemophilia?

Haemophilics may suffer long-term joint pain and deformities, including athritis from bleeding into joints. This can be managed by an orthopaedic surgeon.

Prior to 1985 blood products were not screened for human immunodeficiency virus (HIV), which leads to the development of AIDS. This meant many using these blood products, including clotting factors, contracted the virus.

In 1990 a variety of hepatitis-like symptoms were identified as Hepatitis C which causes serious liver illness. This condition was passed onto many users of clotting factors and blood products.

For several years now, clotting products have undergone a heat treatment to kill the HIV and Hepatitis B and C viruses, preventing transmission. However, there is still the possibility of other infectious agents being transmitted through blood products, so care is needed when handling any blood products or equipment.

Hepatitis B vaccine is recommended for all haemophiliacs as they are at increased risk of contracting this condition from blood products.

A small number of people develop resistance to the blood clotting factors needed and could die from blood loss.

Brain haemorrhage (bleeding into the brain) is a possible complication of haemophilia.

What is Von Willebrand disorder?

Von Willebrand disorder is similar to haemophilia in as far as it affects the function of the blood platelets due to a deficiency of von Willebrand factor.

However, unlike haemophilia, it can affect males or females equally. Effects vary from person to person and generation to generation.

Living with haemophilia

Most people with haemophilia and receiving treatment lead relatively normal lives when receiving treatment.

There are support groups for sufferers where members share common experiences and discuss problems.

Genetic counselling for carriers of haemophilia can be useful when planning a family. Female carriers can be identified by tests, and diagnosis before birth is now possible using amniocentesis screening and genetic testing.