A large difference in desmopressin response was observed between type 1 VWD with and without a VWF gene variant and type 2 VWD. (A) VWF:Ag was higher after desmopressin in type 1 VWD patients without a variant compared with type 1 VWD patients with a variant and type 2 VWD patients. (B-C) VWF:Act and FVIII:C after desmopressin administration was highest in type 1 patients without a variant, followed by type 1 patients with a variant and type 2 VWD patients. (D) All type 1 VWD patients without a variant had a complete response to desmopressin, whereas 66.3% of type 1 patients with a variant and 31.1% of type 2 VWD patients had a complete response. In panels A-C, data are represented as mean and 95% CI. CI, confidence interval.