A multimer pattern with all bands present but in decreased concentrations would be diagnosed with which von Willebrand disease type?

A multimer pattern with all bands present but in decreased concentrations would be diagnosed with which von Willebrand disease type?

• A. Hemophilia
• B. Type 1 vWD
• C. Type 2 vWD
• D. Type 3 vWD

Answer: (B)

The main idea is distinguishing quantitative versus qualitative defects of von Willebrand factor on multimer analysis. If every VWF multimer is present but reduced in amount, the pattern reflects a quantitative deficiency rather than a structural or functional defect. That’s characteristic of Type 1 von Willebrand disease, where there is partial deficiency of VWF with a proportional drop in both antigen and activity across all multimer sizes. In Type 2 vWD, the problem is qualitative—the VWF is abnormal in function or structure, and the multimer pattern is typically distorted, often with loss or reduction of high-molecular-weight multimers or other irregularities. Type 3 vWD shows near-complete absence of VWF, so essentially no multimers are detected. Hemophilia is a separate factor VIII deficiency and would not produce this VWF multimer pattern. So the described pattern—every band present but at reduced concentrations—best fits Type 1 von Willebrand disease.

The main idea is distinguishing quantitative versus qualitative defects of von Willebrand factor on multimer analysis. If every VWF multimer is present but reduced in amount, the pattern reflects a quantitative deficiency rather than a structural or functional defect. That’s characteristic of Type 1 von Willebrand disease, where there is partial deficiency of VWF with a proportional drop in both antigen and activity across all multimer sizes.

In Type 2 vWD, the problem is qualitative—the VWF is abnormal in function or structure, and the multimer pattern is typically distorted, often with loss or reduction of high-molecular-weight multimers or other irregularities. Type 3 vWD shows near-complete absence of VWF, so essentially no multimers are detected. Hemophilia is a separate factor VIII deficiency and would not produce this VWF multimer pattern.

So the described pattern—every band present but at reduced concentrations—best fits Type 1 von Willebrand disease.