Now, a mimic of hemophilia A is von Willebrand disease, which is an inherited problem with primary hemostasis caused by a deficiency of von Willebrand factor.

还有一种类血友病A，即血管性血友病，是一种遗传性的初级止血障碍，由血管性血友病因子（vWF）缺乏引起。

By far the most common of these are deficiencies of factor VIII which gives rise to factor VIIIa and is stabilized by another factor called von Willebrand factor.

目前为止，大多数的血友病通常是因子VIII缺乏症；因子VIII能转变为因子VIIIa，并被血管性血友病因子（vWF）固定。

Type O's can thank lower levels of von Willebrand factor, a blood clotting agent for their protection against heart disease and cognitive decline, but this also means they are more likely to die from severe trauma.

O 型血的人靠较低水平的血管性血友病因子凝血因子来预防心脏病和认知衰退，也意味着他们更有可能会死于严重创伤。