SERPINE1 and hyperhomocysteinemia: History of prior deep venous thrombosis (n = 2), presence of PAI‐1 4G/5G (n = 1) or PAI‐1 4G/4G (n = 1) polymorphisms, hyperhomocysteinemia (n = 3), Factor V Leiden heterozygosity (n = 2), elevated von Willebrand factor (n = 1), elevated factor VIII (n = 2) were identified in eight (22%) individuals with AVN.