Haemophilia

Question 1

What is haemophilia?

Answer 1

Haemophilia is a bleeding disorder, usually inherited with an X-linked recessive inheritance pattern, which results from the deficiency of a coagulation factor.

Question 2

What is the difference between haemophilia A and B?

Answer 2

Haemophilia A results from the deficiency of clotting factor VIII. Haemophilia B results from the deficiency of clotting factor IX.

Question 3

What are the risk factors of haemophilia?

Answer 3

> family history of haemophilia (congenital haemophilia)

> male sex (congenital haemophilia)

> age >60 years (acquired haemophilia)

> autoimmune disorders, inflammatory bowel disease, diabetes, hepatitis, pregnancy, postnatal, or malignancy (acquired haemophilia)

Question 4

What are the signs and symptoms of haemophilia?

Answer 4

> Recurrent or severe bleeding
> Bleeding into muscles
> Prolonged bleeding following heel prick or circumcision
> Mucocutaneous bleeding
> Haemarthrosis
> Excessive bruising
> Menorrhagia
> Extensive

Question 5

What is the epidemiology of haemophilia?

Answer 5

The incidence of congenital haemophilia A is about 1 in 5000 boys/men, whereas the incidence of congenital haemophilia B is about 1 in 30,000 boys/men.

Question 6

What investigations would you do for haemophilia?

Answer 6

> aPTT- Prolonged
plasma factor VIII and IX assay- low
mixing study- aPTT corrected
FBC- normal or low Hb
plain x-rays of specific bony sites- haemarthrosis
antenatal factor VIII or IX mutation analysis by amniocentesis or chorionic villus sampling (CVS)- mutation

All normal:
> prothrombin time (PT)
> plasma von Willebrand factor assay
> plasma factor V, VII assay
> plasma factor XI, XII assay
> closure time/bleeding time and platelet aggregation studies
> serum liver aminotransferases- aspartate aminotransferase [AST] and alanine aminotransferase [ALT]