Typical VWF multimer patterns in classical VWD type 2A. VWF multimers were separated by SDS gel electrophoresis and visualized by immunostaining. (A) Plasma-derived VWF (pdVWF). Lane 1 shows wild-type VWF (VWF-WT); lane 2, VWF of a patient with a group 1 mutation (S1506L); and lanes 3-6, VWF of patients with group 2 mutations (R1597W, M1528V, G1629E, and I1628T). Compared with VWF-WT, patient samples lack HMWMs and show pronounced subbands of VWF (marked by arrows). (B) “Homozygous” rhuVWF. Lane 1 shows rhuVWF-WT; lane 2, group 1 mutant rhuVWF1506L lacking high- and intermediate-molecular-weight multimers of VWF; and lanes 3-6, group 2 mutants rhuVWF1597W, rhuVWF1528V, rhuVWF1629E, and rhuVWF1628T with multimer patterns indistinguishable from rhuVWF-WT. Note that in the recombinant VWF proteins there is no triplet pattern and no subbands, respectively, due to the absence of ADAMTS13 in the expression system. Patient samples were collected over several years and analyzed on different gels. Images were adjusted for size and brightness (Microsoft PowerPoint 2000; Redmond, WA).