Table 1.

Classification of von Willebrand disease.

Quantitative deficiency of VWF

Type 1 Partial quantitative deficiency of VWF

Type 3 Virtually complete deficiency of VWF

Qualitative deficiency of VWF

Type 2 Qualitative deficiency of VWF

- Type 2A Qualitative variants with decreased platelet-dependent function associated with the absence of high and intermediate-molecular-weight VWF multimers

- Type 2B Qualitative variants with increased affinity for platelet GPIb

- Type 2M Qualitative variants with decreased platelet-dependent function not caused by the absence of high-molecular-weight VWF multimers

- Type 2N Qualitative variants with markedly decreased affinity for factor VIII