Genetic analyses of novel compound heterozygous hypodysfibrinogenemia, Tsukuba I: FGG c.1129+62_65 del AATA and FGG c.1299+4 del A.

Introduction: We found a novel hypodysfibrinogenemia designated Tsukuba I caused by compound heterozygous nucleotide deletions with FGG c.1129+62_65 del AATA and FGG c.1299+4 del A on different alleles.

Differences in the function and secretion of congenital aberrant fibrinogenemia between heterozygous γD320G (Okayama II) and γΔN319-ΔD320 (Otsu I).

Background: We encountered two patients with hypodysfibrinogenemia and designated them as Okayama II and Otsu I. Although the affected residue(s) in Okayama II and Otsu I overlapped, functionally determined fibrinogen levels and the ratio of functionally to immunologically determined plasma fibrinogen levels were markedly different.

Methods: DNA sequence and functional analyses were performed for purified plasma fibrinogen.

[Polymorphism frequency of fibrinogen Bβ-chain 448Arg and Lys, and the differences of plasma fibrinogen level and clotting function with three genotypes in Japanese].

The 448th residue in the fibrinogen Bβ-chain molecule is known to be polymorphic (Arg/Lys, R/K), and its allele frequency was previously estimated to be R: 0.85 and K: 0.15 in the US.

Novel heterozygous dysfibrinogenemia, Sumida (AαC472S), showed markedly impaired lateral aggregation of protofibrils and mildly lower functional fibrinogen levels.

Introduction: We encountered a 6-year-old girl with systemic lupus erythematosus. Although no bleeding or thrombotic tendency was detected, routine coagulation screening tests revealed slightly lower plasma fibrinogen levels, as determined by functional and antigenic measurements (functional/antigenic ratio=0.857), suggesting hypodysfibrinogenemia.

Recombinant γT305A fibrinogen indicates severely impaired fibrin polymerization due to the aberrant function of hole 'A' and calcium binding sites.

Introduction: We examined a 6-month-old girl with inherited fibrinogen abnormality and no history of bleeding or thrombosis. Routine coagulation screening tests showed a markedly low level of plasma fibrinogen determined by functional measurement and also a low level by antigenic measurement (functional/antigenic ratio=0.295), suggesting hypodysfibrinogenemia.