Polymorphism rs2066865 in the Fibrinogen Gamma Chain (FGG) Gene Increases Plasma Fibrinogen Concentration and Is Associated with an Increased Microvascular Thrombosis Rate

Abstract

<i>Background and Objective</i>: Thrombosis due to inherited hypercoagulability is an issue that has been raised in microvascular flap surgery previously. We analyzed the association of a single nucleotide polymorphism (SNP) in rs2066865 in the <i>fibrinogen gamma chain</i> (<i>FGG</i>) gene, alteration in plasma fibrinogen concentration, and presence of microvascular flap thrombosis. <i>Materials and Methods</i>: A total of 104 adult patients with microvascular flap surgery were subjected to an analysis of the presence of SNP rs2066865 in the <i>FGG</i> gene. Alterations in plasma fibrinogen concentration according to genotype were determined as a primary outcome, and flap thrombosis was defined as a secondary outcome. <i>Results</i>: Flap thrombosis was detected in 11.5% of patients (<i>n</i> = 12). Successful revision of anastomosis was performed in four patients, resulting in a microvascular flap survival rate of 92.3%. We observed an increase in plasma fibrinogen concentration in genotype G/A and A/A carriers (G/G, 3.9 (IQR 4.76-3.04); G/A, 4.28 (IQR 5.38-3.18); A/A, 6.87 (IQR 8.25-5.49) (A/A vs. G/A, <i>p</i> = 0.003 and A/A vs. G/G, <i>p</i> = 0.001). Within group differences in microvascular flap thrombosis incidence rates were observed-G/G 6/79 (7.59%); G/A 5/22 (22.7%); A/A 1/3 (33.3%) (OR 0.30 95%; CI 0.044 to 0.57), <i>p</i> = 0.016; RR 3.2-when G/G versus G/A and A/A were analyzed respectively. <i>Conclusions</i>: A/A and G/A genotype carriers of a single nucleotide polymorphism in rs2066865 in the <i>fibrinogen gamma chain</i> gene had a higher plasma fibrinogen concentration, and this might be associated with an increased microvascular flap thrombosis incidence rate. Determined polymorphism could be considered as a genetic marker associated with microvascular flap thrombosis development. To confirm the results of this study, the data should be replicated in a greater sample size.