Phenotypes associated with the disease congenital factor XII deficiency (OMIM:234000):
- Reduced factor XII activity (HP:0004841): Decreased activity of coagulation factor XII. Factor XII (fXII) is part of the intrinsic coagulation pathway and binds to exposed collagen at site of vessel wall injury, activated by high-MW kininogen and kallikrein, thereby initiating the coagulation cascade. Evidence: IEA. (OMIM:234000)
- 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:234000)
- Autosomal recessive inheritance (HP:0000007): 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 individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele). Evidence: IEA. (OMIM:234000)
- Prolonged partial thromboplastin time (HP:0003645): Increased time to coagulation in the partial thromboplastin time (PTT) test, a measure of the intrinsic and common coagulation pathways. Phospholipid, and activator, and calcium are mixed into an anticoagulated plasma sample, and the time is measured until a thrombus forms. Evidence: IEA. (OMIM:234000)