Genetic variants in VWF in type 1 VWD. Frequency of genetic variants in VWF for 5 large population studies of type 1 VWD including the United Kingdom,²⁷  European Union,²⁹  Canada,²⁸  Germany,³⁰  and United States.²⁶  Overall 65% had a variant in VWF found, but 35% did not.