Factor V Leiden is a genetic disorder that affects the clotting process in the body. It is named after the city of Leiden in the Netherlands, where it was first identified. This condition is caused by a mutation in the gene that produces a protein called factor V, which is involved in the clotting cascade.
The most common cause of Factor V Leiden is an inherited mutation in the F5 gene. This gene provides instructions for making the factor V protein, which is essential for the normal clotting of blood. In individuals with Factor V Leiden, a single nucleotide change in the F5 gene leads to the production of an abnormal form of factor V known as factor V Leiden.
Genetic Mutation: The mutation responsible for Factor V Leiden is a single nucleotide substitution in the F5 gene. This mutation replaces the nucleotide guanine (G) with adenine (A) at position 1691. As a result, the amino acid arginine is replaced by glutamine at position 506 in the factor V protein. This alteration makes factor V resistant to degradation by activated protein C, a natural anticoagulant in the body. The mutated factor V Leiden protein remains active for a longer duration, leading to an increased risk of abnormal blood clot formation.
Inheritance: Factor V Leiden is inherited in an autosomal dominant pattern, which means that a person only needs to inherit one copy of the mutated gene from either parent to develop the disorder. If one parent has Factor V Leiden, there is a 50% chance of passing the mutation on to each child. However, not all individuals with the mutation will develop abnormal blood clots, as other factors such as lifestyle, environment, and additional genetic variations can influence the risk.
Prevalence: Factor V Leiden is the most common inherited clotting disorder in the general population, particularly among individuals of European descent. It is estimated that about 5% of Caucasians in the United States carry one copy of the Factor V Leiden mutation. The prevalence is lower in other populations, such as African Americans and Asians.
Risk Factors: While the primary cause of Factor V Leiden is the genetic mutation, several risk factors can increase the likelihood of developing abnormal blood clots in individuals with the mutation. These risk factors include:
Conclusion: Factor V Leiden is primarily caused by a genetic mutation in the F5 gene, resulting in the production of an abnormal form of factor V. This mutation is inherited in an autosomal dominant pattern and is more prevalent in individuals of European descent. While the mutation itself increases the risk of abnormal blood clot formation, certain risk factors such as hormonal medications, pregnancy, smoking, obesity, immobilization, surgery, and trauma can further increase the likelihood of clotting events. It is important for individuals with Factor V Leiden to be aware of these risk factors and take appropriate preventive measures to reduce the risk of complications.