Hemophilia B Kashihara is a severe hemorrhagic disorder in which the factor IX antigen is present in normal amounts but factor IX biological activity is markedly reduced.
DNA sequence analysis of the Factor IX gene from a hemophilia B patient (98% Factor IX antigen; less than 0.01 unit/ml clotting activity) has identified a point mutation in exon II.
Deficiency in coagulation factor IX, a plasma glycoprotein constituent of the clotting cascade, results in hemophilia B, an inherited recessive X-linked bleeding disorder.
Crude barium chloride eluates prepared from 12 unrelated patients with cross-reacting material positive (CRM+) haemophilia B were activated with celite eluate, the reaction products resolved after reduction by 13% SDS-PAGE, and factor IX antigenic material detected by probing with radiolabelled immunopurified rabbit anti-factor IX antiserum followed by autoradiography.
When factor IX Hilo was added back to depleted patient plasma, to normal plasma depleted of factor IX by the same affinity column, or to plasma from a CRM- hemophilia B patient, the ox brain prothrombin time was significantly prolonged.
Three point mutations in the factor IX genes of five hemophilia B patients. Identification strategy using localization by altered epitopes in their hemophilic proteins.
Factor IX Niigata is a mutant factor IX responsible for the moderately severe hemophilia B in a patient who has a normal level of factor IX antigen with reduced clotting activity (1-4% of normal).
Factor IXAlabama is a variant factor IX molecule responsible for a clinically moderate form of hemophilia B. Twenty-five kilobases (kb) of the variant gene, including seven exons coding for the structural protein, were cloned and characterized.
We show that a point mutation causing hemophilia B changes the amino acid at position -4 in the propeptide region of factor IX from an arginine to a glutamine, which results in the expression of a stable longer protein with 18 additional amino acids of the N-terminal propeptide region still attached.
Hemophilia B Chapel Hill is a mild hereditary hemorrhagic disorder in which the factor IX antigen is present in normal amounts but factor IX biological activity is markedly reduced.