What is the difference between hemophilia a and hemophilia b

Bleeding can be external or internal. The symptoms depend on the Hemophilia type A or B and severity mild, moderate, or severe. Apr 24, Featured Experts Dr. Reddy Pandurang H. Thakur Sr. Inhibitor development - the occurrence of high affinity anti-FVIII or anti-FIX antibodies that neutralize the activity of the infused clotting factor is a major complication of replacement therapy in hemophilia patients.

However, this approach is expensive and impractical for the patients. Different lines of evidence seem to support a difference in bleeding severity between HA and HB. The pathophysiology of the two disorders is, indeed, diverse, with a different distribution of the factors in the body and, in keeping with this, the PK characteristics of infused factors are significantly different.

However, because of the rarity of the disorders, no prospective, head-to-head comparative studies have been carried out, and the modern approach in the pediatric hemophilia population i. Improved replacement therapy with extended half-life concentrates with to day intervals between infusions and sustained high FIX troughs 51 are greatly improving the clinical outcome and, even more so, the quality of life of HB patients when compared to HA patients.

The promising perspectives of gene therapy are painting a future scenario in which the decision to offer this option to patients with HB and very mild clinical problems could be challenging considering the costs involved and the yet unknown long-term effects.

National Center for Biotechnology Information , U. Journal List Haematologica v. Prepublished online Aug 8.

Giancarlo Castaman 1 and Davide Matino 2. Author information Article notes Copyright and License information Disclaimer. Received Mar 5; Accepted Jun 5. Material published in Haematologica is covered by copyright. All rights are reserved to the Ferrata Storti Foundation. Copies of published material are allowed for personal or internal use. Reproducing and sharing published material for commercial purposes is not allowed without permission in writing from the publisher.

This article has been cited by other articles in PMC. Comparison of gene defects in hemophilia A and hemophilia B Both F8 and F9 genes are located on the X chromosome, F8 gene being at the end of the long arm at Xq28 5 and F9 IX gene on the long arm, more towards the centromere, at Xq Open in a separate window.

Figure 1. Similarities and differences in hemophilia A and B clinical phenotype The numerous bleeding episodes that individuals with severe hemophilia experience can lead to long-term disability. Orthopedic surgery The need for orthopedic surgical treatment can be considered a surrogate of severity of hemophilia disease. Table 1. Summary of main clinical findings reported in the studies. Potential mechanisms affecting the variability in disease severity between hemophilia A and hemophilia B Several possible underlying biological explanations for differences in disease severity can be hypothesized and are presented here.

Figure 2. Conclusions Different lines of evidence seem to support a difference in bleeding severity between HA and HB. References 1. Berntorp E, Shapiro AD. Modern haemophilia care. J Thromb Haemost. Severe hemophilia with mild bleeding phenotype: molecular characterization and global coagulation profile.

Mannucci PM, Franchini M. Is haemophilia B less severe than haemophilia A? Characterization of the human factor VIII gene.

Complete nucleotide sequences of the gene for human factor IX antihemophilic factor B. Molecular genotyping of the Italian cohort of patients with hemophilia B. The molecular basis for cross-reacting material-positive hemophilia A due to missense mutations within the A2-domain of factor VIII. Castaman G, Fijnvandraat K. Molecular and clinical predictors of inhibitor risk and its prevention and treatment in mild hemophilia A. Ribosome readthrough accounts for secreted full-length factor IX in hemophilia B patients with nonsense mutations.

Hum Mutat. Goodeve AC. Hemophilia B: molecular pathogenesis and mutation analysis. In this study, the authors present evidence that severe hemophilia B may be clinically less severe than hemophilia A. Here, authors cite a study that establishes a link between non-null mutations and a milder clinical phenotype in severe hemophilia.

Another point authors argue is that a recent report showed that the hemophilia severity score HSS is higher in patients with severe hemophilia A than in those with severe hemophilia B. And, a Canadian study showed that patients with severe hemophilia B bled less frequently than patients with hemophilia A, while another study performed in Italy demonstrated that patients with hemophilia B had fewer hemarthroses and lower World Federation of Hemophilia ultrasound scores.

People with mild haemophilia usually will only need treatment if they are injured or need surgery. What is the difference between haemophilia A and B? Question: Is there a major difference between hemophilia A and hemophilia B or is it slight and what is the difference?