Family pedigree and analysis of plasma vWF from two families with type 2M vWD. (A and B) Three generations of the family pedigree are illustrated showing affected (shaded symbol) and unaffected (open symbol) family members for Family A (A) and Family B (B). vWF:RCo/vWF:Ag ratios determined from testing in a clinical laboratory are shown below selected symbols (U/dL). (C and D) Autoradiograms of plasma vWF multimer structure from Family A (C: AII-1, AIII-1), Family B (D: BII-1, BI-1, BIII-1, BIII-2), or normal pooled human plasma (NP) resolved by 0.65% SDS/agarose gel electrophoresis and detected with ¹²⁵I–anti-vWF Ab as described in Materials and Methods.