Analysis of an Inherited FXII Deficiency Pedigree Associated with Double Heterozygous Mutations in the F12 Gene

This article is intended to identify the potential mutations of the FXII gene ( F12 ) in an inherited FXII deficiency pedigree and illuminate the pathogenesis of the disease. The coagulation FXII activity (FXII:C) and FXII antigen (FXII:Ag) were inspected by one-stage clotting assay and enzyme-linked immunosorbent assay(ELISA), respectively. Polymerase chain reaction amplification (PCR) was performed and the F12 gene was sequenced directly. A molecular model of FXIIprotein was established for further analysis. ClustalX-2.1-win and online bioinformatic software were used to estimate the conservatism and possible impact of the protein change. The proband presented prolonged APTT(180 s) and extreme low FXII:C and FXII:Ag (both