title: Coexistence of hypofibrinogenemia and factor V Leiden mutation: is the balance shifted to thrombosis?
abstract: Congenital hypofibrinogenemia and afibrinogenemia are usually associated with an increased risk of bleeding, but occurrence of arterial or venous thrombosis has also been reported in individuals with fibrinogen deficiency. This study reports on a 25-year-old patient with hypofibrinogenemia (fibrinogen 0.6 g/l) and congenital thrombophilia due to heterozygous factor V Leiden mutation who developed spontaneous deep-vein thrombosis (DVT) in the right lower extremity. Regardless of hypofibrinogenemia, he was receiving anticoagulant therapy over 6 months, with no occurrence of bleeding. His father is also a heterozygous carrier of factor V Leiden, but with normal fibrinogen level and he remained asymptomatic despite having experienced surgery in the past. This case, as well as data from literature, suggests that risk of thrombosis in carriers of factor V Leiden mutation is not counterbalanced by moderate congenital hypofibrinogenemia, and that antithrombotic prophylaxis should not be omitted in high-risk situations for occurrence of thrombosis in patients with coinheritance of hypofibrinogenemia and factor V Leiden mutation.
authors.affiliation: aFaculty of Medicine, Belgrade University bClinic of Haematology cClinic for Digestive Diseases, Clinical Centre of Serbia dInstitute of Medical Biochemistry, Military Medical Academy eInstitute of Human Genetics and Genetic Engineering, Belgrade, Serbia.
authors.forename: Predrag
authors.initials: P
authors.lastname: Miljić
authors.forename: Ružica
authors.initials: R
authors.lastname: Nedeljkov-Jančić
authors.forename: Marinko
authors.initials: M
authors.lastname: Zuvela
authors.forename: Vesna
authors.initials: V
authors.lastname: Subota
authors.forename: Valentina
authors.initials: V
authors.lastname: Dorđević
mesh_terms: D000328:Adult; D000347:Afibrinogenemia / Q000097:blood / Q000150:complications / Q000151:congenital* / Q000235:genetics; D005165:Factor V / Q000235:genetics* / Q000378:metabolism; D005340:Fibrinogen / Q000235:genetics* / Q000378:metabolism; D006579:Heterozygote; D006801:Humans; D008297:Male; D017354:Point Mutation; D019851:Thrombophilia / Q000097:blood / Q000150:complications / Q000235:genetics*; D020246:Venous Thrombosis / Q000097:blood / Q000150:complications / Q000235:genetics*
chemical_list: C095381:factor V Leiden; D005165:Factor V; D005340:Fibrinogen