Coagulation factor 5

The gene encodes a crucial coagulation factor, which when deficient causes a serious bleeding disorder, but if the cleavage site is altered, then its inactivation is impossible, which results in untameable coagulation, an increased risk of thrombosis.

Epidemiology

The mutation factor V Leiden is of European origin. About 5% of the population in these countries is heterozygous. In Africa and Asia this mutation is rare. There are no broad statistical data concerning the other mutations of this gene.

Gene Structure

The gene F5 is about 70kb in size. It is located on Chromosome 1 (1q23). It consists of 25 exons.

Protein Structure

The structure is similar to coagulation factor VIII. We have the same domains (A1-A2-B-A3-C1-C2). The B domain is very much glycosilated.

Phenotype

The clinical picture depends on the type of mutation. If mutation results in thrombophilia we find thromboembolic diseases early in life. Characteristically the thrombosis might occur in atypical localizations. An influence on the development of cardiovascular disease is discussed too.

Pathology

Mutations in this coagulation factor can cause either hemophilia or thrombophilia.

Test Strategy

Patients suspected to have thrombophilia. Family screening.

Interpretation

The mutation factor V Leiden increases the annual risk for venous thrombosis up to 3 times in case of heterozygosity. In homozygous carriers the risk is about 28 times increased.

Genetests:

Related Diseases:

Thromboembolic diseases
	Autosomal dominant protein C deficiency
		PROC
	Autosomal dominant protein S deficiency
		PROS1
	Autosomal recessive protein C deficiency
		PROC
	Autosomal recessive protein S deficiency
		PROS1
	F2
	F5
	Factor XII deficiency
		F12
	HABP2
	Hyperhomocysteinemic thrombosis
		CBS
	Hypoplasminogenemia
		Dysplasminogenemia
			PLG
		Hypoplasminogenemia
			PLG
	MTHFR
	PAI transcription modulator
		SERPINE1
	Protein Z deficiency
		PROZ
		SERPINA10
	SERPINC1
	THBD
	Thrombophilia due to heparin cofactor 2 deficiency
		SERPIND1
	VKORC1

References:

1.	None (2001) Factor V Leiden: a clinical review.

2.	Orphanet article Orphanet ID 121673

3.	NCBI article NCBI 2153

4.	OMIM.ORG article Omim 227400

5.	Wikipedia article Wikipedia EN (Factor_V)