Concerning thrombotic risk, VWF:Ag and FVIII:C were significantly higher in patients with than in patients without a history of AT (244.0 ± 120.2% vs. 176.5 ± 64.9%, p = 0.02; 239.2 ± 81.7% vs. 187.4 ± 49.4%, p = 0.01, respectively). This evidence concerns the gene F8 and ataxia telangiectasia.