Decreased VWF:RCo/VWF:Ag ratio in healthy control subjects with p.D1472H. This graph shows VWF:RCo/VWF:Ag ratios for healthy control subjects (59 African Americans and 113 Caucasians) enrolled in the US Zimmerman Program study grouped by presence or absence of the p.D1472H sequence variation.⁷  Mean ratios for each group are shown at the top of the graph. There were 7 subjects with ratios <0.6, all of which were either heterozygous or homozygous for p.D1472H. None of the subjects without p.D1472H had ratios <0.7.