Von Willebrands Disease

Question 1

Define:

Answer 1

Bleeding disorder caused by abnormal or . deficiency of vWF

Question 2

What are the functions of vWF:

Answer 2

Binds platelets to subendothelium
Makes platelets bind to each other
Bind F8 protecting it from destruction in the circulation

Question 3

Aetiology/risk factors:

Answer 3

Type 1- vWF works normally but is reduced (60-80%). AUTOSOMAL DOMINANT

Type 2- normal levels of vWF but is abnormal(20-30%). AUTOSOMAL DOMINANT.

Type 3- no vWF - very severe and rare. AUTOSOMAL RECESSIVE

Question 4

Symptoms and signs:

Answer 4

Menorrhagia - heavy and prolonged periods
Easy bruising
Prolonged bleeding after a dental procedure
Epistaxis
Haematuria
Haematochezia
Heavy bleeding from a cut or accident

Question 5

Investigations:

Answer 5

Bleeding time increased

APTT - increased

F8 - decreased

vWF Ag - decreased type 1 and 3. Normal in type 2.

Ristocetin factor - normal in type 2. Abnormal in type 1 and 3