VWF and von Willebrand disease (hereditary or acquired): Another study found a particular association with the VWD Type 2A mutation S1506L.64 Interestingly, vascular malformations and GI bleeding are also associated with acquired VWD, often in combination with aortic stenosis, in a triad that has been named Heyde syndrome (rev in65), which is also associated with loss of VWF HMWM.