Von Willebrand disease: classification and epidemiology

Area of Science:

• Hematology
• Genetics
• Clinical Medicine

Background:

• Von Willebrand disease (VWD) is an inherited bleeding disorder characterized by heterogeneous clinical and laboratory phenotypes.
• Diagnosis relies on bleeding history, low von Willebrand factor (VWF) levels, and autosomal inheritance.
• VWD classification includes quantitative (Types 1, 3) and qualitative (Type 2 A, B, M, N) deficiencies.

Purpose of the Study:

• To review the diagnostic criteria and classification of Von Willebrand disease (VWD).
• To discuss the challenges in diagnosing VWD, particularly mild cases, due to confounding factors affecting VWF levels.
• To highlight recent genetic findings that may alter the estimated prevalence of VWD.

Main Methods:

• Review of epidemiological and genetic studies on Von Willebrand disease (VWD) prevalence.
• Analysis of diagnostic criteria including bleeding history, VWF levels, and inheritance patterns.
• Examination of factors influencing plasma VWF levels in clinical practice.

Main Results:

• Estimated VWD prevalence is ~1% based on epidemiological data.
• Clinical diagnosis can be challenging due to variable VWF levels, especially in mild VWD.
• Prevalence of clinically relevant VWD may be between 1/1,000-10,000 in referred populations.
• Recent genetic data suggest pathogenic VWF variants may be more common than 1%.

Conclusions:

• Accurate diagnosis of VWD requires careful consideration of clinical, laboratory, and genetic factors.
• Confounding factors complicate VWD diagnosis, impacting prevalence estimates.
• Further research into genetic prevalence is needed to fully understand the impact of VWF variants.