Haemophilia

Question 1

define haemophilia?

Answer 1

bleeding disorder resulting from an inherited x linked recessive pattern causing deficiency of a clotting factor

Question 2

what are the 3 subtypes of haemophilia?

Answer 2

Haemophilia A: MOST COMMON - deficiency in factor 8

Haemophilia B: deficiency in factor 9

Haemophilia C: RARE - deficiency in factor 11

Question 3

what is acquired haemophilia?

Answer 3

suddenly appearing autoanitbodies which interfere with factor 8- v rare and no genetic inheritance pattern

Question 4

outline the epidemiology of haemophilia?

Answer 4

Haemophilia A incidence: 1/10,000 males

Haemophilia B incidence: 1/25,000 males

Haemophilia C is more common in Ashkenazi Jews

Question 5

outline the extrinsic and intrinsic clotting pathways?

Answer 5

Question 6

describe APTT and PT and bleeding time for haemophilia, Von willebrand’s disease and vitamin K deficiency?

Answer 6

Question 7

Define haemophillia

Answer 7

bleeding diatheses resulting from an inherited deficiency of a clotting factor

Question 8

outline the aetiology of haemophilia?

Answer 8

Haemophilia A and B have X-linked recessive inheritance

30% of cases are new mutations

Due to its inheritance pattern, Haemophilia is mainly seen in MALES - females who are carriers have some bleeding symptoms

Question 10

what are the rare cases of females having haemophilia?

Answer 10

Turners, extreme lyonization, etc

Question 11

what are the risk factors for haemophilia?

Answer 11

• 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 12

what are the presenting symptoms of haemophilia?

Answer 12

Symptoms usually begin in early childhood

Swollen painful joints occurring spontaneously or with minimal trauma (haemarthroses)

Painful bleeding into muscles

Haematuria

Excessive bruising or bleeding after surgery or trauma

FEMALE carriers are usually asymptomatic, but may experience excessive bleeding after trauma

Generally speaking, bleeding in haemophilia is DEEP (into muscles and joints)

Question 13

what are the signs of haemophilia on physical examination?

Answer 13

Multiple bruises

Muscle haematomas

Haemarthroses

Joint deformity

Nerve palsies (due to nerve compression by haematomas)

Signs of iron deficiency anaemia

Question 14

what are the appopriate investigations for haemophilia?

Answer 14

Clotting screen (high APTT) - if corrected after a mixing study (when norm plasma is incubated into patient for 2 hours) then highly suggestive of haemophilia

Coagulation factor assays (low factor 8, 9 or 11 (depending on type of haemophilia))

FBC – rule out thrombocytopenia as a cause of bleeding and to check if anaemia is present due to severe or prolonged bleeding

LFTs - liver dysfunction can contribute to prolonged APTT

VWf assay – rule out von willebrands disease

x rays- arthropathy