Factor 5 Deficiency
Country: United States
Date: April 2005
What is factor 5 deficiency, and is it a mutation in the
When you get a cut, there are many steps in the blood clotting process. You
don't want your blood to clot for no reason, so there is a very complicated
process with many steps to complete before the cut is sealed off. There are
12 steps in the process and they are numbered. They were named in the order
in which they were discovered and don't necessarily go in order. Factor 5 is
also known as Leiden. Yes, it is a mutation that can be inherited.Here is a
link that will explain this more in detail.
Factor V is a protein (probably an enzyme) involved in the blood cloting
mechanism. It is a less severe form of hemophilia and goes by several
different names: thrombophilia, Owren's disease, Leiden's disease and
parahemophilia. It is caused by the mutation of a gene located on chromosome
1, so it is not a sex-linked mutation like the hemophilia caused by Facdtor
VIII deficiency. For further information do a search on Google and you'll
get more than a million hits/
Ron Baker, Ph.D.
Factor V Leiden is a mutation in a gene on chromosome 1 that causes
thrombophilia, an increased risk of blood clots. The normal version of the
gene codes for factor V (Roman numeral 5), one of the factors involved in
normal blood clotting. The Factor V Leiden mutation results in a faulty
factor V molecule.
A person who is a heterozygote for the gene inherits a factor V Leiden
mutation from either mother or father, and a normal gene from the other
parent. A person who inherits the gene from both parents (a homozygote) has
two faulty copies of the gene in every cell.
Other mutations (errors) in this gene are also known.
DNA testing can tell whether a person has one or two faulty copies of the
For more information, contact a genetic counselor
or see Gene
Clinics at http://www.geneclinics.org/profiles/factor-v-leiden/ or OMIM at
Sarina Kopinsky, MSc, CGC
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Update: June 2012