PB0358 - Spectrum of Von Willebrand Disease (vWD) among children at a paediatric hospital in Singapore

Background: Von Willebrand disease (VWD) is a common inherited bleeding disorder caused by low levels of or dysfunctional von Willebrand factor (vWF). VWD can be secondary to quantitative (Type I and Type III) or qualitative (Type II) defects in vWF. The most common bleeding manifestation is mucosal bleeding, with the bleeding phenotype varying depending on the subtype. Local data on the characteristics of patients with vWD in Singapore is lacking.

Aims: The objective of this study is to review the clinical characteristics of paediatric patients with vWD at our centre, which is the largest paediatric centre in Singapore.

Methods: This was a retrospective study conducted at our centre. All paediatric patients diagnosed with vWD who were on active follow up during the period of January 2017 to December 2023 were included in the study.

Results: 26 patients with vWD were included in this study. 76.9% were diagnosed with Type I vWD, 19.2% with Type II vWD and 3.9% with Type III vWD. The median age at diagnosis was 5.8 years (range 0-13.6 years) and 34.6% of them had a positive family history of vWD. 38.5% had bleeding manifestations at presentation with epistaxis being the most common. 3 patients (11.5%) had significant annualized bleeding rates (ABR) (ABR range: 8-24) and were recommended for prophylactic vWF replacement – 2 had Type II vWD and 1 had Type III vWD. 2 of them were eventually started on prophylaxis (1 with Alphanate® and 1 with Vonvendi®). Their ABRs had significant improvement after commencement of prophylaxis.

Conclusion(s): The majority of paediatric patients with vWD in our institution have Type I vWD and do not have significant bleeding manifestations. An on-demand vWF replacement regime is appropriate for this group of patients. For those with significant ABRs, vWF prophylaxis is effective in reducing the ABRs.