F2 and thrombophilia: Genomic studies and coagulation workup can provide valuable information to better understand their clinical importance.<h4>Key clinical question</h4>We describe the case of a woman with a duplication of the entire prothrombin gene.<h4>Clinical approach</h4>A 42-year-old woman presented for thrombophilia screening following a history of unprovoked arterial and superficial venous thrombotic episodes.