Pathophysiology of SOS is still not completely understood but is probably related to the development of a pro-thrombotic state associated with up-regulation of plasminogen activator inhibitor 1 (PAI.1), vonWillenbrand factor (vWF) and Matrix Metalloproteinases (MMP’s) [8-10] The role of angiogenesis is probably confirmed by the presence of sinusoidal capillarization and the protective role of bevacizumab, an antiangiogenic monoclonal antibody [3,11]. The gene discussed is VWF; the disease is spondylo-ocular syndrome.