Molecular characterization of haemophilia B (HB) at the factor IX gene (F9) is essential to establish diagnosis, confirm genotype-phenotype correlations and to advise in genetic counselling.
In this study, a more comprehensive analysis of the molecular pathology of haemophilia B in Turkey revealed one large deletion and 33 point mutations in the FIX gene of 34 unrelated patients.
To determine if the factor IX (FIX) germline mutational pattern in AmerIndians differs from the common and putative endogenous pattern, FIX gene mutations were characterized in an initial sample of 10 AmerIndian Peruvian patients with hemophilia B.
Modification of the N-terminus of human factor IX by defective propeptide cleavage or acetylation results in a destabilized calcium-induced conformation: effects on phospholipid binding and activation by factor XIa.
We conclude that this method can be advantageously used for diagnosis purposes in a routine laboratory involved in haemophilia B diagnosis and report nine previously undescribed haemophilia B families with their factor IX mutation.
In the present study, we report the application of polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) analysis to the screening of seven functionally important factor IX gene (FIX) regions (total length 2.66 kb) in 9 unrelated haemophilia B patients of Portuguese or African origin.
We have characterized at the DNA and protein levels a mutant factor IX, factor IX Strasbourg 2, which is responsible for a severe form (< 0.01 U/ml) of haemophilia B.
This patient also developed an antibody to factor IX during replacement therapy, which suggests that deletion of the factor IX gene is not necessary for development of the antibody in hemophilia B patients.