A novel fibrinogen variant – Liberec: dysfibrinogenaemia associated with γ Tyr262Cys substitution

Abstract

A case of dysfibrinogenaemia, found by routine coagulation testing, was genetically identified as a novel fibrinogen variant (gamma Y262C) that has been named Liberec.

Three cases of abnormal fibrinogens: Šumperk (Bβ His67Leu), Uniãov (Bβ Gly414Ser), and Brno (γArg275His)

“…In variant Šumperk, hypofibrinogenemia wasfirst diagnosed in a21-year-old female during routine testing performed before surgicalremoval of fibroadenoma.The fibrinogen level (Clauss) determinedo ns everal examinations wasf ound to be in the 0.5-1.4 g/l range (normal range 2-4.2 g/l). The immunoturbidimetric fibrinogen levelwas foundtobe1.41 g/l and measuredas previouslydescribed (10)(11)(12). The patient reported menorrhagia.…”

Abnormal Fibrinogen Zlín (γThr21Ile) with Missense Mutation Causing Hypofibrinogenemia

“…Coagulation testing revealed a decreased fibrinogen level in both the functional and the immunoturbidimetric assay (1.4 and 1.7 g/l, respectively). Functional fibrinogen and its total level were determined according to the Clauss method [6] and according to immunoturbidimetric measurement as reported previously [7]. Thrombin and reptilase polymerization were measured using turbidity at 350 nm in 20-second intervals for 40 min after the addition of thrombin (0.9 NIH U/ml final thrombin activity) or reptilase (625× diluted TEClot BAT Reptilase; TECO, Neufahrn, Germany) [8].…”

Dysfibrinogenemia in childhood: two cases of congenital dysfibrinogens

“…Fibrin polymerization curve measurement Fibrin polymerization was measured in plasma samples after the addition of either human thrombin (0.1 NIH U/ ml, final concentration) or reptilase (0.1 mg/ml; TEClot BAT Reptilase, TECO, Neufahrn, Germany), as described earlier [15][16][17].…”

“…The molecule consists of three different pairs of polypeptide chains (Aa, Bb, and g) each encoded by a distinct gene (FGA, FGB, and FGG), clustered on chromosome 4q32.1 [3]. N-terminal parts of the Aa chain [fibrinopeptide A (fpA), 16 amino acids] and the Bb chain [fibrinopeptide B (fpB), 14 amino acids] are situated in the central part of the molecule. Fibrinopeptides block polymerization of the molecules and play various important physiological roles [4].…”