- Molecular Weight: 56,000
- Normal plasma concentration 0.5 μg/ml
- 10-40% of normal concentration required for haemostasis
- Vitamin K dependent blood clotting factor
- Activated FIXa is cofactor of Factor VIII
Factor IX
From Ganfyd
Common Name:Factor_IX
Biochemical Information
Molecular Structure
Important Issues in Man
Relevant Clinical Literature
UK Guidance
Other Wikis
Medpedia on Factor IX (Less technical, good quality control)
Wikipedia on Factor IX (Less technical, ? quality control)
The factor IX gene on the long arm of the X chromosome (Xq27.1) encodes a precursor protein consisting of a signal peptide, propeptide followed by a glutamic acid–rich domain, 2 epidermal growth factor (EGF) domains, an activation peptide, and a catalytic domain. Activation of factor IX occurs by cleavage by factor VIIa-tissue factor complex or activated factor XI. This releases the activation peptide resulting in a circulating light chain and a heavy chain connected by the disulfide bond. Numerous posttranslational modifications are necessary for its normal function, including tyrosine sulfation, serine phosphorylation, and O- and N-linked glycosylation. Haemophilia B is caused by various mutations of the factor IX gene. A rare type of warfarin sensitivity results from another mutation (Ala-10) which causes bleeding with a therapeutic range INR but the APPT is disproportionately prolonged.
