Molecular characterization of 11 novel mutations in patients with heterozygous and homozygous FV deficiency.

Coagulation factor V (FV) has an important role in the blood coagulation cascade, in both the pro- and anticoagulant pathways. FV deficiency is a rare bleeding disorder with variable phenotypic expression. We report a cohort of 10 patients with mild-severe FV deficiency in whom a total of 11 novel mutations were identified. Three patients were compound heterozygous for two mutations, whereas each of the remaining patients had a single heterozygous variant. FV levels did not correlate with either the type of mutation identified or the bleeding diathesis exhibited by the patients. Although considered to have an autosomal recessive mode of inheritance, patients with a single missense mutation may present with a significant bleeding history. The addition of a significant number of previously unidentified mutations to the public domain will contribute to the knowledge and understanding of the molecular pathology of this rare disorder.