However, this hypothesis has not been tested <i>in vivo</i> The relationship between platelet desialylation and the platelet count was probed in 36 patients with type 2B von Willebrand disease (p.R1306Q, p.R1341Q, and p.V1316M mutations) and in a mouse model carrying the severe p.V1316M mutation (the 2B mouse).
In the VWD-2B mouse model expressing high levels of mVWF/p.V1316M (423%), similar to what is found in inflammatory pathologies, no significant difference was observed between mice expressing mVWF/WT and mVWF/p.V1316M.
In addition, persons with MPS, but not unaffected family members, had loss of plasma (but not platelet) high molecular weight VWF multimers, and were heterozygous for the previously reported V1316M type 2B VWD mutation.
We describe a newborn with a VWD type 2B due to the heterozygous missense mutation V1316M who presented the atypical feature of giant platelets in peripheral blood.