Distinguishing types 1 and 2M von Willebrand disease

Area of Science:

• Hematology
• Genetics
• Clinical Diagnostics

Background:

• Von Willebrand disease (VWD) encompasses various subtypes, with type 1 and type 2M presenting diagnostic challenges.
• Type 1 VWD involves quantitative deficiency of von Willebrand factor (VWF), while type 2M indicates a qualitative defect.
• Accurate differentiation is critical as type 2M VWD poses a higher bleeding risk and may respond differently to treatments like desmopressin.

Observation:

• A case is presented where type 2M VWD mimicked the clinical and laboratory presentation of type 1 VWD.
• This diagnostic ambiguity highlights the need for careful evaluation beyond initial assessments.

Findings:

• Standard laboratory assays were instrumental in distinguishing the true nature of the VWD in the presented case.
• Genetic analysis confirmed the diagnosis of type 2M VWD, identifying a specific mutation (3943C>T leading to R1315C).

Implications:

• The findings underscore the importance of utilizing comprehensive diagnostic tools for VWD subtyping.
• Correctly identifying type 2M VWD ensures appropriate patient management, considering its distinct bleeding risks and therapeutic considerations.
• This case serves as a valuable example for clinicians managing patients with suspected VWD.