Type 2B Von Willebrand Disease MimickingAutoimmune Thrombocytopenia in the Neonatal Period

Background: Type 2B von Willebrand disease (VWD) is a hereditary bleeding disorder caused by changes in the von Will ebrand factor (VWF), which increases the binding of VWF to platelets. Type 2B VWD may present with thrombocytopenia. Case Report: A four-day-old newborn was brought to the neonatal intensive care unit presenting with bleeding and severethrombocytopenia. The platelet level was 10,000/mm3, and coagulation tests were normal. There were no clinical evidenceof sepsis; therefore, alloimmune or autoimmune thrombocytopenia was suspected. When we found out that her motherand relatives had intermittent thrombocytopenia, advanced tests were performed. Ristocetin cofactor activity was low; type2 VWD was considered. Using low-dose ristocetin, we increased platelet aggregation. Heterozygous c.3946G > A (p.Val 1316Met) mutation was detected, and type 2B VWD was diagnosed. Conclusion: Type 2B VWD may cause a diagnostic problem in the differential diagnosis of neonatal thrombocytopeniaincluding neonatal autoimmune thrombocytopenia.