- Reduced factor VIII activity (HP:0003125): Reduced activity of coagulation factor VIII. Factor VIII (fVIII) is a cofactor in the intrinsic clotting cascade that is activated to fVIIIa in the presence of minute quantities of thrombin. fVIIIa acts as a receptor, for factors IXa and X. Evidence: IEA. (OMIM:193400)
- Menorrhagia (HP:0000132): Prolonged and excessive menses at regular intervals in excess of 80 mL or lasting longer than 7 days. Evidence: TAS. (OMIM:193400)
- Aortic valve stenosis (HP:0001650): The presence of a stenosis (narrowing) of the aortic valve. Evidence: IEA. (OMIM:193400)
- Prolonged whole-blood clotting time (HP:0005542): An abnormal prolongation (delay) in the time required by whole blood to produce a visible clot. Evidence: IEA. (OMIM:193400)
- Impaired platelet aggregation (HP:0003540): An impairment in the rate and degree to which platelets aggregate after the addition of an agonist that stimulates platelet clumping. Platelet aggregation is measured using aggregometer to measure the optical density of platelet-rich plasma, whereby platelet aggregation causes the plasma to become more transparent. Evidence: IEA. (OMIM:193400)
- Gastrointestinal angiodysplasia (HP:0000471): Dysplasia affecting the vasculature of the gastrointestinal tract. Evidence: IEA. (OMIM:193400)
- Prolonged bleeding time (HP:0003010): Prolongation of the time taken for a standardized skin cut of fixed depth and length to stop bleeding. Evidence: IEA. (OMIM:193400)
- Joint hemorrhage (HP:0005261): Hemorrhage occurring within a joint. Evidence: IEA. (OMIM:193400)
- Reduced quantity of Von Willebrand factor (HP:0012147): Decreased quantity of von Willebrand factor. Evidence: TAS. (OMIM:193400)
- Typified by incomplete penetrance (HP:0003829): Description of conditions in which not all individuals with a given genotype exhibit the disease. Penetrance is the proportion that develop disease given a lifespan of 80 years. Evidence: TAS. (OMIM:193400)
- Prolonged bleeding after dental extraction (HP:0006298): Prolonged bleeding post dental extraction sufficient to require medical intervention. Evidence: PCS. Frequency: 4/12. (PMID:12649144)
- Bruising susceptibility (HP:0000978): An ecchymosis (bruise) refers to the skin discoloration caused by the escape of blood into the tissues from ruptured blood vessels. This term refers to an abnormally increased susceptibility to bruising. The corresponding phenotypic abnormality is generally elicited on medical history as a report of frequent ecchymoses or bruising without adequate trauma. Evidence: PCS. Frequency: 5/12. (PMID:12649144)
- Persistent bleeding after trauma (HP:0001934). Evidence: PCS. Frequency: 4/12. (PMID:12649144)
- Prolonged bleeding after surgery (HP:0004846): Bleeding that persists longer than the normal time following a surgical procedure. Evidence: PCS. Frequency: 4/12. (PMID:12649144)
- Gastrointestinal hemorrhage (HP:0002239): Hemorrhage affecting the gastrointestinal tract. Evidence: IEA. (OMIM:193400)
- Epistaxis (HP:0000421): Epistaxis, or nosebleed, refers to a hemorrhage localized in the nose. Evidence: PCS. Frequency: 8/12. (PMID:12649144)
- Mitral valve prolapse (HP:0001634): One or both of the leaflets (cusps) of the mitral valve bulges back into the left atrium upon contraction of the left ventricle. Evidence: IEA. (OMIM:193400)
- Autosomal dominant inheritance (HP:0000006): A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in heterozygotes. In the context of medical genetics, an autosomal dominant disorder is caused when a single copy of the mutant allele is present. Males and females are affected equally, and can both transmit the disorder with a risk of 50% for each child of inheriting the mutant allele. Evidence: IEA. (OMIM:193400)
These phenotypes are associated with the disease von Willebrand disease 1 (OMIM:193400).