Phenotypic characterization of family members. (A) Multimer distribution of plasma VWF in heterozygous and homozygous family members relative to normal pooled plasma (NPP). Heterozygous and, to a greater degree, homozygous family members show a relative reduction in high molecular weight multimers. (B) Multimer analysis was performed using 1-dimensional densitometry and the relative percentage of high-, intermediate-, and low-molecular-weight multimers was reported. The greatest reduction in high-molecular-weight material was observed in the IC.