RESUMO
OBJECTIVE@#To test the anticoagulation functions, perform the genetic diagnosis and analyze the clinical characteristics in a family with combined heterozygous genetic variants of PROC and PROS1.@*METHODS@#Peripheral blood was collected from all the family members. Hematological phenotypes and activity of anticoagulant factors were analyzed. Target genes were amplified by PCR from DNA isolated from peripheral blood, and then were analyzed by Sanger DNA sequencing.@*RESULTS@#Many members in the family displayed the combined genetic variants in protein C and protein S, and six family members accompanied by deep venous thrombosis (DVT). The influences of genetic and secondary factors on the incidence of venous thrombosis in the family members were analyzed. The results showed that in this family, carriers of combined protein C and protein S gene defects had a higher incidence of VTE, but acquired factors still played a key role in the eventual thrombotic symptoms.@*CONCLUSION@#Venous thromboembolism (VTE) is a multifactorial disease, the combined genetic heterozygous mutations of protein C and S is an important genetic factor, and the clinical phenotype show a high heterogenicity, the secondary factors contribute to the VTE incidence.