[Postpartum fatal pulmonary embolism with F5 gene mutation: a case report].

Pulmonary embolism (PE) is one of the leading causes of maternal death. Various clinical and environmental risk factors can cause PE. Here, we reported an uncommon PE case with multiple etiological causes, including caesarean section, overweight, anti-cardiolipin antibody positive, and factor 5 gene mutation. The patient was a 25-year-old woman who developed cardiac asystole and apnea one day after cesarean delivery due to pulmonary embolism. After cardiopulmonary resuscitation and thrombolytic therapy, high doses of epinephrine were still needed to maintain blood pressure and heart rate, so we treated her with venoarterial extracorporeal membrane oxygenation (ECMO) to maintain systemic circulation. She progressively improved and was discharged on oral warfarin treatment. Comprehensive laboratory tests revealed a positive anticardiolipin antibody. Through whole exon gene sequencing, we identified a novel mutation (A2032➝G) in the F5 gene. This mutation was predicted to result in the replacement of lysine with glutamate at position 678, close to one of the APC cleavage sites. P.Lys678Glu was found to be a detrimental mutation by SIFT software and suspected detrimental by Polyphen-2 software. Attention should be paid to the etiological screening of young patients with pulmonary embolism, which is helpful in guiding the anticoagulant scheme and anticoagulant duration, and is of great significance in preventing thrombosis recurrence and complications.