Which von Willebrand disease type has four subtypes and autosomal dominant inheritance?

Which von Willebrand disease type has four subtypes and autosomal dominant inheritance?

• A. Type 1
• B. Type 2
• C. Type 3
• D. Type 4

Answer: (B)

Von Willebrand disease type two is defined by qualitative defects in von Willebrand factor and includes four subtypes: 2A, 2B, 2M, and 2N. Each subtype represents a distinct problem with how vWF functions—affecting platelet adhesion or the vWF-FVIII interaction—yet they share an autosomal dominant inheritance pattern in most families. This combination of multiple subtypes and dominant inheritance is why this type is the best answer. In contrast, type one is a partial quantitative deficiency without a set of four subtypes, and type three involves a near-complete absence of vWF with autosomal recessive inheritance. Type four is not part of the current standard classification.

Von Willebrand disease type two is defined by qualitative defects in von Willebrand factor and includes four subtypes: 2A, 2B, 2M, and 2N. Each subtype represents a distinct problem with how vWF functions—affecting platelet adhesion or the vWF-FVIII interaction—yet they share an autosomal dominant inheritance pattern in most families. This combination of multiple subtypes and dominant inheritance is why this type is the best answer.

In contrast, type one is a partial quantitative deficiency without a set of four subtypes, and type three involves a near-complete absence of vWF with autosomal recessive inheritance. Type four is not part of the current standard classification.