Histopathological analysis revealed platelet aggregation and the extravascular presence of von Willebrand factor (VWF) and ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13), indicating their association with SOS/VOD development, suggesting that the ADAMTS13 activity/concentration ratio can serve as an early biomarker for guiding therapeutic interventions. This evidence concerns the gene VWF and spondylo-ocular syndrome.