Haemophilia (zero to finals)

Question 1

Haemophilia A is caused by a deficiency of what coagulation factor?

Answer 1

Caused by a deficiency of factor VIII.

Question 2

Haemophilia A is caused by a deficiency of what coagulation factor?

Answer 2

Caused by a deficiency of factor IX.

Question 3

What is haemophilia A and B?

Answer 3

Haemophilia A and B are severe inherited bleeding disorders.

Question 4

What is the inheritance pattern for haemophilia?

Answer 4

Both haemophilia A and B are X-linked recessive diseases.

All X chromosomes need to have the abnormal gene to have haemophilia.

Question 5

Why are males most commonly affected by haemophilia?

Answer 5

Males only have one X chromosome and require only one abnormal copy to have the disease.

Females have two X chromosomes, so when one copy is affected, they are asymptomatic carriers of the gene.

Therefore, haemophilia A and B primarily affect males. For a female to be affected, they would require an affected father and a mother who is either a carrier or affected.

Question 6

What are those with haemophilia most at risk of?

Answer 6

Both haemophilia A and B are severe bleeding disorders.

Patients can bleed excessively in response to minor trauma and are at risk of spontaneous bleeding without any trauma.

Question 7

When do most haemophilia cases commonly present?

Answer 7

Most cases present in neonates or early childhood. It can present with intracranial haemorrhage, haematomas and cord bleeding in neonates.

Question 8

How can haemophilia lead to joint damage and deformity?

Answer 8

Spontaneous bleeding into joints (haemarthrosis) such as the ankle, knee or elbow.

Question 9

How can haemophilia lead to compartment syndrome?

Answer 9

Bleeding into the muscles can cause compartment syndrome.

Question 10

Apart from the joints and muscles, what other areas of bleeding can be present?

Answer 10

Other areas of bleeding include:

• Oral mucosa
• Nosebleeds (epistaxis)
• Gastrointestinal tract
• Urinary tract, causing haematuria
• Intracranial haemorrhage
• Surgical wounds

Question 11

How is haemophilia diagnosed?

Answer 11

Bleeding scores, coagulation factor assays and genetic testing.

Question 12

What is the management of haemophilia and what is a complication of this?

Answer 12

The affected clotting factors (VIII or IX) can be given by intravenous infusion, either regularly or in response to bleeding.

A complication of this treatment is the formation of antibodies (called inhibitors) against the treatment, resulting in it becoming ineffective.