As vWD is heritary, there is usually evidence of a family history of bleeding problems, but the symptoms of VWD can vary a lot within a family and sometimes be so mild so that it was not recognised. Sometimes vWD occurs due to a spontaneous change in the vWD gene before the baby is born.
vWD Types 1 and 2 are usually inherited in what is known as a "dominant" pattern. This means that a parent who has vWD has a one in two (50%) chance of passing a VWD gene on to each of his or her children.
Type 3 vWD, however, is usually inherited in a "recessive" pattern. This type occurs when the child inherits the gene from both parents. Even if both parents have mild symptoms or no symptoms at all, their children may be severely affected.