Which type of von Willebrand disease is most common, least severe, and autosomal dominant?

Which type of von Willebrand disease is most common, least severe, and autosomal dominant?

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

Answer: (A)

VWD types are distinguished by how much functional von Willebrand factor is available and whether the defect is quantitative or qualitative. The most common and usually mild form is a partial quantitative deficiency of VWF, inherited in an autosomal dominant pattern, so a single mutated gene can produce the condition and many family members may be affected. Because enough VWF is still present to support hemostasis in most situations, bleeding tends to be mild and mucocutaneous rather than severe. In contrast, qualitative defects (Type 2) show variable and often more pronounced bleeding depending on the specific abnormality, and near-complete absence of VWF (Type 3) leads to more serious, life-threatening bleeding and is typically autosomal recessive. Type 4 isn’t a standard category in current classification, so it isn’t the correct label for this clinical picture.

VWD types are distinguished by how much functional von Willebrand factor is available and whether the defect is quantitative or qualitative. The most common and usually mild form is a partial quantitative deficiency of VWF, inherited in an autosomal dominant pattern, so a single mutated gene can produce the condition and many family members may be affected. Because enough VWF is still present to support hemostasis in most situations, bleeding tends to be mild and mucocutaneous rather than severe. In contrast, qualitative defects (Type 2) show variable and often more pronounced bleeding depending on the specific abnormality, and near-complete absence of VWF (Type 3) leads to more serious, life-threatening bleeding and is typically autosomal recessive. Type 4 isn’t a standard category in current classification, so it isn’t the correct label for this clinical picture.