Laboratory Diagnosis of Factor V Leiden Publisher



Jozdani S ; Shabannezhad A ; Safarian N ; Shams M
Source: Laboratory Investigations of Thrombophilia: Clinical and Practical Aspects Published:2025

Abstract

Factor V Leiden (FVL) is a genetic mutation characterized by a G-to-A transition at nucleotide 1691 of the FV gene, resulting in the substitution of arginine with glutamine at position 506 (R506Q). This gain-of-function mutation is a significant hereditary cause of venous thromboembolism (VTE) due to its role in conferring resistance of FV to activated protein C (APC). In individuals with the heterozygous form of FVL, the risk of VTE is increased 3–8 times, while homozygous individuals face an 80-fold increase in risk. However, VTE generally requires the presence of additional risk factors for its manifestation. The APC resistance test is commonly used for the initial screening of thrombophilia, and this test has undergone various modifications to minimize the influence of interfering factors and reduce false results. Definitive diagnosis of FVL is achieved through genetic testing to identify the specific mutation. Various techniques for genetic testing have been employed, with the most practical methods discussed in this chapter. Management of patients with FVL generally adheres to the established VTE guidelines, though additional complications, especially in pregnant women, require specialized clinical attention. © 2025 The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG.