Type 1 von Willebrand disease is characterized by a decreased plasma concentration of functionally normal von Willebrand factor (vWF) whereas type 2M is characterised by an abnormal vWF displaying decreased affinity for platelets.
Type 1 von Willebrand disease (VWD) is characterized by a personal and family history of bleeding coincident with reduced levels of normal plasma von Willebrand factor (VWF).
Type 1 von Willebrand disease can be divided into three groups where (1) fully penetrant VWF mutations appear sufficient to explain the low plasma von Willebrand factor and bleeding, (2) VWF mutation may act as a risk factor for bleeding in combination with blood group O and/other unknown genetic factors, and (3) classic VWF mutations are absent but VWF may still play a role in some cases and blood group O is common.
Type 1 von Willebrand disease (VWD) is transmitted mainly as a dominant trait - especially in forms involving von Willebrand factor (VWF) levels below 20 U/dL - and less frequently as a recessive trait.
Type 1 von Willebrand disease (VWD) is a common inherited disorder characterized by mild to moderate bleeding and reduced levels of von Willebrand factor (VWF).
von Willebrand factor (VWF) levels in healthy individuals and in patients with type 1 von Willebrand disease (VWD) are influenced by genetic variation in several genes, e.g.VWF, ABO, STXBP5 and CLEC4M.
von Willebrand factor (VWF) levels in healthy individuals and in patients with type 1 von Willebrand disease (VWD) are influenced by genetic variation in several genes, for example, <i>VWF</i>, <i>ABO</i> and <i>STXBP5</i>.
A heterozygous mutation, predicting a lysine to glutamate (K174E) substitution in P2Y(12), was identified in one case with mild type 1 von Willebrand disease (VWD) and a VWF defect.
A new category of either dominant or recessive mild VWD type 1 due to mutations in the D4, B1-B3 and C1-C2 domains of the VWF gene consists of two groups: one group with mild VWD with normal VWF multimers and a second group with mild/moderate VWD with smeary multimer pattern.
A new set of missense mutations in D4, B1-B3 and C1-C2 domains has been discovered as the cause of a mild VWD type 1 secretion defect with normal VWF multimers or smeary VWF multimeric pattern.
A novel von Willebrand disease-causing mutation (Arg273Trp) in the von Willebrand factor propeptide that results in defective multimerization and secretion.
A plasma sample from 49 patients previously diagnosed with VWD (type 1; type 2A, type 2M, type 2B) through phenotype and VWF (von Willebrand factor) analysis and 15 healthy controls was analysed.
A receiver operating characteristic curve was used to identify the optimal cutoff of VWFpp/VWF:Ag for discrimination of patients with a modestly increased (most VWD cases) versus those with a markedly increased clearance (AVWS and VWD type 1 Vicenza), and this cutoff was identified at the value of 3.9 (sensitivity: 0.70, specificity: 0.97).
Administration of 1-desamino-8-D-arginine-vasopressin (DDAVP) to patients with type 1 von Willebrand disease and to healthy individuals causes a rapid increase in plasma VWF levels.
Also, in patients with vWD type 1 and borderline to normal ristocetin-cofactor (vWF:RCo) activity values, collagen receptor density correlates inversely with closure time in a high shear stress system (platelet function analyzer [PFA-100]).
Also, in patients with vWD type 1 and borderline to normal ristocetin-cofactor (vWF:RCo) activity values, collagen receptor density correlates inversely with closure time in a high shear stress system (platelet function analyzer [PFA-100]).
Among the major subtypes, type I von Willebrand disease represents by far the more prevalent category (about 70%) and includes cases with a partial deficiency of plasma von Willebrand factor and no evidence of qualitative defects.
As an example, presence of VWF levels lower than 40 IU/dL in at least 2 family members (including the proband) and a bleeding score of at least 1 were found to be required for a final odd of VWD higher than 2.0 (false-positive rate less than one-half).