Haemophilia B

Haemophilia B
Classification and external resources
Specialty	Haematology
ICD-10	D67
ICD-9-CM	286.1
OMIM	306900
DiseasesDB	5561
MedlinePlus	000539
eMedicine	emerg/240
Patient UK	Haemophilia B
MeSH	D002836

Haemophilia B (or hemophilia B) is a blood clotting disorder caused by a mutation of the factor IX gene, leading to a deficiency of factor IX. It is the second-most common form of haemophilia, rarer than haemophilia A. Haemophilia B was first recognized as a a different kind of haemophilia in 1952.^[1] It is sometimes called Christmas disease, named after Stephen Christmas, the first patient described with this disease.^[2] In addition, the first report of its identification was published in the Christmas edition of the British Medical Journal.^[3]

Treatment

Treatment (bleeding prophylaxis) is by intravenous infusion of factor IX. Factor IX has a longer half life than factor VIII (deficient in haemophilia A) and as such factor IX can be transfused less frequently.

Genetics

The factor IX gene is located on the X chromosome (Xq27.1-q27.2). It is an X-linked recessive trait, which explains why, as in haemophilia A, usually only males are affected. One in 20,000–30,000 males are affected.

In 1990, George Brownlee and Merlin Crossley showed that two sets of genetic mutations were preventing two key proteins from attaching to the DNA of people with a rare and unusual form of haemophilia B – haemophilia B Leyden – where sufferers experience episodes of excessive bleeding in childhood but have few bleeding problems after puberty.^[4] This lack of protein attachment to the DNA was thereby turning off the gene that produces clotting factor IX, which prevents excessive bleeding.^[5]

In 2013, Merlin Crossley discovered the third and final protein causing haemophilia B Leyden.^[6]

Pathophysiology

Factor IX deficiency leads to an increased propensity for haemorrhage. This is in response to mild trauma or even spontaneously, such as in joints (haemarthrosis) or muscles.

European royal families

A study published in 2009 identified the blood disease affecting the royal families of Great Britain, Germany, Russia and Spain as haemophilia B on the basis of genetic markers.^[7]^[8]

References

↑ "Haemophilia B (Factor IX Deficiency) information | Patient". Patient. Retrieved 2016-04-21.
↑ Christmas' disease at Who Named It?
↑ Biggs R, Douglas AS, MacFarlane RG, Dacie JV, Pitney WR, Merskey C, O'Brien JR (1952). "Christmas disease: a condition previously mistaken for haemophilia". Br Med J 2 (4799): 1378–82. doi:10.1136/bmj.2.4799.1378. PMC 2022306. PMID 12997790.
↑ http://ghr.nlm.nih.gov/condition/hemophilia
↑ Crossley, M; Brownlee, G. G. (1990). "Disruption of a C/EBP binding site in the factor IX promoter is associated with haemophilia B". Nature 345 (6274): 444–6. doi:10.1038/345444a0. PMID 2342576.
↑ http://www.biotechlearn.org.nz/news_and_events/news/2013_archive/royal_disease_mystery_solved
↑ Michael Price (8 October 2009). "Case Closed: Famous Royals Suffered From Hemophilia". ScienceNOW Daily News. AAAS. Retrieved 9 October 2009.
↑ Evgeny I. Rogaev; et al. (8 October 2009). "Genotype Analysis Identifies the Cause of the "Royal Disease"". Science. Retrieved 9 October 2009.

External links

GeneReviews/NCBI/NIH/UW entry on Hemophilia B
Hemophilia: What is it? at CSHL Your Genes, Your Health
hemophilia B at GPnotebook

Diseases of clotting (D50–69,74, 280–287)

Coagulation/
coagulopathy

↑

Hyper- coagulability	primary: Antithrombin III deficiency Protein C deficiency/Activated protein C resistance/Protein S deficiency/Factor V Leiden Prothrombin G20210A Sticky platelet syndrome acquired:Thrombocytosis essential DIC Purpura fulminans autoimmune Antiphospholipid

↓

Hypo-
coagulability

Thrombocytopenia	Thrombocytopenic purpura: ITP Evans syndrome TM TTP Upshaw Schulman syndrome Heparin-induced thrombocytopenia May–Hegglin anomaly

Platelet function	adhesion Bernard–Soulier syndrome aggregation Glanzmann's thrombasthenia platelet storage pool deficiency Hermansky–Pudlak syndrome Gray platelet syndrome

Clotting factor	Hemophilia A/VIII B/IX C/XI von Willebrand disease Hypoprothrombinemia/II XIII Dysfibrinogenemia Congenital afibrinogenemia

Sex linkage: X-linked disorders

X-linked recessive

Immune	Chronic granulomatous disease (CYBB) Wiskott–Aldrich syndrome X-linked severe combined immunodeficiency X-linked agammaglobulinemia Hyper-IgM syndrome type 1 IPEX X-linked lymphoproliferative disease Properdin deficiency

Hematologic	Haemophilia A Haemophilia B X-linked sideroblastic anemia

Endocrine	Androgen insensitivity syndrome/Spinal and bulbar muscular atrophy KAL1 Kallmann syndrome X-linked adrenal hypoplasia congenita

Metabolic	Amino acid: Ornithine transcarbamylase deficiency Oculocerebrorenal syndrome Dyslipidemia: Adrenoleukodystrophy Carbohydrate metabolism: Glucose-6-phosphate dehydrogenase deficiency Pyruvate dehydrogenase deficiency Danon disease/glycogen storage disease Type IIb Lipid storage disorder: Fabry's disease Mucopolysaccharidosis: Hunter syndrome Purine-pyrimidine metabolism: Lesch–Nyhan syndrome Mineral: Menkes disease/Occipital horn syndrome

Nervous system	X-linked mental retardation: Coffin–Lowry syndrome MASA syndrome X-linked alpha thalassemia mental retardation syndrome Siderius X-linked mental retardation syndrome Eye disorders: Color blindness (red and green, but not blue) Ocular albinism (1) Norrie disease Choroideremia Other: Charcot–Marie–Tooth disease (CMTX2-3) Pelizaeus–Merzbacher disease SMAX2

Skin and related tissue	Dyskeratosis congenita Hypohidrotic ectodermal dysplasia (EDA) X-linked ichthyosis X-linked endothelial corneal dystrophy

Neuromuscular	Becker's muscular dystrophy/Duchenne Centronuclear myopathy (MTM1) Conradi–Hünermann syndrome Emery–Dreifuss muscular dystrophy 1

Urologic	Alport syndrome Dent's disease X-linked nephrogenic diabetes insipidus

Bone/tooth	AMELX Amelogenesis imperfecta

No primary system	Barth syndrome McLeod syndrome Smith–Fineman–Myers syndrome Simpson–Golabi–Behmel syndrome Mohr–Tranebjærg syndrome Nasodigitoacoustic syndrome

X-linked dominant

X-linked hypophosphatemia Focal dermal hypoplasia Fragile X syndrome Aicardi syndrome Incontinentia pigmenti Rett syndrome CHILD syndrome Lujan–Fryns syndrome Orofaciodigital syndrome 1 Craniofrontonasal dysplasia

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