Von Willebrand dz

Question 1

Heterozygous defect with reduced production of normal vWF

Answer 1

VWD type 1
Autosomal dominant

Question 2

Multimerization defect with absent large/intermediate size multimers

Answer 2

VWD type 2A
Auto dominant

Question 3

Gain of function in VWF
Too adherent to platelets - large multimers are attached to plts and not circulating

Answer 3

VWD type 2B
Auto dominant

Question 4

Loss of function
VWF doesn’t bind well to plts

Answer 4

VWD type 2M
Auto dominant

Question 5

Loss of vWF binding function to FVIII

Answer 5

VWD type 2N
Auto dominant - compound heterozygotes with type 1

Think of this when plasma FVIII activity is reduced (ineffective binding decreases the half life of FVIII) and less than the plasma vWF antigen level

Question 6

Absence of vWF production

Answer 6

VWD type 3
Auto recessive