hemophilia B; factor IX deficiency ; Christmas disease
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Epidemiology
- occurs in men
- less common than hemophilia A (0.1)
Genetics
- X-linked recessive
- transmitted from unaffected mother to male offspring
Clinical manifestations
- history of spontaneous bleeding since childhood
- excessive bleeding following surgery & dental procedures
- recurrent hemarthrosis leading to contractures & crippling degenerative joint disease
- hemorrhages into muscle
- excessive bleeding from minor trauma
- easy bruising
- no excessive bleeding after minor cuts
- clinically indistinguishable from hemophilia A,
- female carriers are asymptomatic.
Laboratory
- complete blood count (CBC) - evaluate anemia
- prothrombin time (PT) is normal
- prolonged partial thromboplastin time (PTT)
- mixing studies:
- factor IX plasma activity: < 1% of normal (severe)[2]
- PCR/southern blot
- see ARUP consult[3]
Complications
- factor 9 inhibitors (up to 3-5%)
Management
- fresh frozen plasma
- cryoprecipitate
- factor 9 concentrate
- recombinant factor IXa (Benefix)
- recombinant factor IX Fc fusion protein (Aprolix)
- gene therapy[5]
- intravenous infusion of a single dose of a factor IX transgene delivered with an adenovirus vector
- 4 of 7 patients able to discontinue Benefix vs Aprolix
- beneficial effects in all 7 patients up to 3 years
- exercise reasonable for children with hemophilia[4]
Notes
- in 1952, one of the early researchers of the disease, Dr. R.G. Macfarlane used the patient's surname, Christmas, to refer to the disease & also to refer to the clotting factor which he called the 'christmas factor'
- at the time. Stephen Christmas was a 5-year-old boy
- he died in 1993 at the age of 46 from AIDS contracted through treatment with blood products
More general terms
Additional terms
- coagulation factor IX; Christmas factor; plasma thromboplastin component; PTC; contains: coagulation factor IXa light chain; coagulation factor IXa heavy chain (F9)
- factor IX gene mutation
- hemophilia A; factor VIII deficiency
References
- ↑ DeGowin & DeGowin's Diagnostic Examination, 6th edition, RL DeGowin (ed), McGraw Hill, NY 1994, pg 885
- ↑ 2.0 2.1 Medical Knowledge Self Assessment Program (MKSAP) 11, 14, 16, 17, 18, 19. American College of Physicians, Philadelphia 1998, 2006, 2012, 2015, 2018, 2022
- ↑ 3.0 3.1 ARUP Consult: Hemophilia - Factor VIII or IX Deficiency The Physician's Guide to Laboratory Test Selection & Interpretation https://www.arupconsult.com/content/hemophilia
- ↑ 4.0 4.1 Broderick CR et al Association Between Physical Activity and Risk of Bleeding in Children With Hemophilia JAMA. 2012;308(14):1452-1459 <PubMed> PMID: https://www.ncbi.nlm.nih.gov/pubmed/23047359 <Internet> http://jama.jamanetwork.com/article.aspx?articleid=1377921
Manco-Johnson MJ Collision Sports and Risk of Bleeding in Children With Hemophilia JAMA. 2012;308(14):1480-1481 <PubMed> PMID: https://www.ncbi.nlm.nih.gov/pubmed/23047364 <Internet> http://jama.jamanetwork.com/article.aspx?articleid=1377908 - ↑ 5.0 5.1 Nathwani AC et al. Long-term safety and efficacy of factor IX gene therapy in hemophilia B. N Engl J Med 2014 Nov 20; 371:1999 <PubMed> PMID: https://www.ncbi.nlm.nih.gov/pubmed/25409372 <Internet> http://www.nejm.org/doi/full/10.1056/NEJMoa1407309
- ↑ Anello J, Feinberg B, Heinegg J et al Hemophilia Guidelines on management of acute joint bleeds and chronic synovitis in hemophilia by the United Kingdom Haemophilia Centre Doctors' Organisation. Medscape: New Guidelines and Recommendations, August 2017. http://reference.medscape.com/viewarticle/884517