The presence of Factor V Leiden factor mutation increased the risk of isolated DVT 8-fold (Odds ratio, OR 7.7 95%; 3.9–15.3) and the risk of isolated thrombosis of the PA only 1.5-fold (OR, 1.6 95%; 0.7–2.7) compared to the patients without this mutation. This evidence concerns the gene F5 and deep vein thrombosis.