What is factor V Leiden deficiency?
” That does not exist. However, it is terminology that is not infrequently, though incorrectly, used by physicians. Typically the physicians mean “factor V Leiden”. Factor V deficiency is an inherited disorder, in which the clotting factor V is low. A bleeding problem results. The disorder is very rare, occurring in only one in 1 million people. Thus, there are only approximately 270 patients in the United States with this disorder. It is inherited as an autosomal recessive disorder, which means that an individual needs to be homozygous for the disorder (i.e. have 2 bad genes) to develop symptoms. Patients may have bleeding as newborns. However, 50 % of patients are not diagnosed until adulthood. The diagnosis is made by finding low factor V activity levels, usually between 1 and 20 % of normal. If treatment is needed, fresh frozen plasma (= FFP) is typically given. Factor V Leiden is a completely different inherited disorder, in which factor V is mutated in a specific spot (R506Q, als
