VWF and hemophilia A: Finally, type 2N (AR) affects vWF-FVIII binding resulting in a decreased FVIII level and symptoms corresponding to hemophilia A. The mutations may be detected in the D’ or D3 domain in homozygous form, or patients may be compound heterozygotes with one mutation in the D’ or D3 domain and with another one elsewhere in VWF leading to null mutation [20].