VWF sequence variants: Innocent until proven guilty

Abstract

William James, the 19th century American philosopher, famously asserted, "To study the abnormal is the best way of understanding the normal." In this issue of Blood, using a distinctly non-Jamesian approach, Bellissimo and colleagues shed new light on our understanding of normal genetic variation in von Willebrand factor (VWF) through the study of ethnically diverse healthy controls and, in doing so, exonerate a number of benign sequence variants previously regarded as pathogenic mutations.