Genetic polymorphisms influencing total and γ' fibrinogen levels and fibrin clot properties in Africans
Summary Inter-ethnic variation in fibrinogen levels is hypothesized to be the result of differences in genetic background. No information is available regarding the contribution of genetics to fibrinogen γ′ in Africans. Only limited information is available regarding the interaction between genotypes and total and γ′ fibrinogen concentration in determining fibrin clot properties. Our aim was to investigate the effect of polymorphisms in the fibrinogen and Factor XIII genes on total and γ′ fibrinogen and clot properties (turbidimetry) in 2010 black Africans as well as to determine their interactions. Significant associations were observed between rs1049636 (FGG gene), with total fibrinogen levels and between rs2070011 (FGA promoter area) and fibrinogen γ′ levels. Significant associations were observed between single nucleotide polymorphisms (SNPs) in the FGA (rs2070011), FGB (rs1800787) and FGG (rs1049636) genes and fibre size. Significant interactions were found between total and/or γ′ fibrinogen levels and SNPs in the FGA (rs2070011), FGB (rs2227385, rs1800787, rs1800788, rs4220) and F13A1 genes (rs5985) in determining clot properties. The different SNPs influenced the relationships between total and γ′ fibrinogen levels with clot properties in opposing directions. Genetic influences may be ethnic-specific and should not only focus on fibrinogen concentration, but also on functionality in determining its role in CVD.