VWF and von Willebrand disease 1: The enrichment of novel or rare SNVs in GPCR genes mediating platelet aggregation among type 1 VWD patients, and the absence of the same variants from control subjects supports a contribution from loci other than VWF to the bleeding phenotype of patients with type 1 VWD, which is consistent with the view of mild type 1 VWD as a polygenic disorder.