VWF and Von Willebrand disease: Clinical exome sequencing identified a heterozygous variant of uncertain significance in two genes: VWF and SERPINE1, the VWF gene is associated with Von Willebrand disease (VWD) types 1 and 3; however, further analysis of Von Willebrand factor (VWF) antigen levels and ristocetin cofactor activity revealed normal results, effectively ruling out VWD.