is a candidate regulator of platelet count in people of Bangladeshi ancestry.

Background: Blood platelets are mediators of atherothrombotic disease and are regulated by complex sets of genes. Association studies in European ancestry populations have already detected informative platelet regulatory loci. Studies in other ancestries can potentially reveal new associations because of different allele frequencies, linkage structures, and variant effects.

Pseudohomozygous dysfibrinogenemia.

Hypodysfibrinogenemia (HD) is a heterogeneous disorder in which plasma fibrinogen antigen and function are both reduced but discordant. This report addresses the key clinical question of whether genetic analysis enables clinically useful subclassification of patients with HD. We report a new case and identify a further eight previously documented cases that have the laboratory features of HD but biallelic inheritance of quantitative and qualitative fibrinogen gene variants.

TEG PlateletMapping assay results may be misleading in the presence of cold stored platelets.

Background: Viscoelastic tests (VETs) are used widely to monitor hemostasis in settings such as cardiac surgery. There has also been renewed interest in cold stored platelets (CSPs) to manage bleeding in this setting. CSPs are reported to have altered hemostatic properties compared to room temperature platelets (RTPs), including activation of GPIIb/IIIa.

Monoallelic loss-of-function THPO variants cause heritable thrombocytopenia.

We report rare monoallelic variants of that alter intracellular trafficking and diminish thrombopoietin secretion. Affected cases have autosomal-dominant thrombocytopenia but no other hematological features.

Differential effects of direct factor IIa and factor Xa inhibitors in protein C-deficient plasma detected using thrombin generation and viscoelastometry assays.

Introduction: Protein C (PC) deficiency results in dysregulated thrombin generation and increases thrombosis risk.

Methods: In order to investigate the potential effects of anticoagulant drugs in PC deficiency, we evaluated the pharmacodynamic effect of selective direct factor (F) IIa inhibitors (dabigatran and argatroban), selective direct FXa inhibitors (rivaroxaban and apixaban) and an indirect FXa/FIIa inhibitor (enoxaparin) in commercial PC-deficient plasma using thrombin generation and viscoelastometry assays modified to reflect PC anticoagulant activity.

Results: Endogenous thrombin potential (ETP) and peak thrombin concentration (PTC) were increased in PC-deficient plasma but this corrected completely with PC concentrate.