Picture Prognosis

A 14-month-old boy born to first-degree consanguineous parents presented with recurrent gingival bleeding, spontaneous epistaxis, prolonged bleeding after vaccinations, and widespread ecchymoses. Platelet count, PT, aPTT, factors VIII/IX, and von Willebrand factor levels were normal. Platelet aggregation studies showed absent aggregation to all agonists except ristocetin. What's your diagnosis?