It was reported that the prothrombin gene mutation was seen in 5.5% of patients with thrombosis and 1.2% in normal individuals.22 Caprini et al. reported that this rate was 17% in patients with vein thrombosis history and 18.2% in patients with pulmonary embolism history.22 In a study that was carried out without making a distinction of young or elder age RVO, prothrombin gene mutation rate was determined as 4.2%.25 Despite this fact, in our study such rate was found as 10% (four patients). This evidence concerns the gene F2 and pulmonary embolism.