von Willebrand disease combined with other hemostasis disorders: an overlooked clinical entity.

von Willebrand disease (VWD) is common, affecting ∼1% of the general population. Due to this relatively high prevalence, it can co-occur with other coagulation disorders. However, combined defects are often underrecognized in clinical practice. Diagnostic anchoring, overlapping symptoms, and limited access to comprehensive hemostatic and genetic testing contribute to these missed diagnoses. A growing number of case reports, case series, and cohort studies have documented the coinheritance of VWD with hemophilia A or B, rare coagulation factor deficiencies, and platelet function disorders. In some cohorts, up to one-third of cases with mild VWD had an additional hemostatic defect. Emerging genomic data also suggest that multiple low-frequency variants affecting hemostasis can co-occur in the same individual, particularly in populations with founder effects or high rates of consanguinity. Combined defects can alter bleeding severity, complicate diagnosis, and affect treatment decisions. Broader awareness and multidisciplinary evaluation are critical for addressing this underappreciated aspect of inherited bleeding disorders.