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Inherited prekallikrein deficiency

MedGen UID:
Concept ID:
Disease or Syndrome
Synonyms: congenital prekallikrein deficiency; Congenital prekallikrein deficiency; fletcher factor (prekallikrein) deficiency; Fletcher Factor deficiency; hereditary prekallikrein deficiency; inherited prekallikrein deficiency; PKK deficiency; prekallikrein deficiency; prekallikrein deficiency, congenital
Modes of inheritance:
Autosomal recessive inheritance
MedGen UID:
Concept ID:
Intellectual Product
Source: Orphanet
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).
Gene (location): KLKB1 (4q35.2)
Monarch Initiative: MONDO:0012901
OMIM®: 612423
Orphanet: ORPHA749


Prekallikrein deficiency (PKKD) is a rare asymptomatic clotting defect characterized by prolongation of activated partial thromboplastin time (summary by Saito et al., 1981). [from OMIM]

Clinical features

From HPO
Prolonged partial thromboplastin time
MedGen UID:
Concept ID:
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.
Abnormal bleeding
MedGen UID:
Concept ID:
Pathologic Function
An abnormal susceptibility to bleeding, often referred to as a bleeding diathesis. A bleeding diathesis may be related to vascular, platelet and coagulation defects.
Reduced circulating prekallikrein concentration
MedGen UID:
Concept ID:
Reduced concentration of prekallikrein (PK; also known as Fletcher factor) in the blood circulation. PK is the precursor of plasma kallikrein, a serine protease that activates kinins. PK is cleaved to produce kallikrein by activated Factor XII.

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  

Recent clinical studies


Girolami A, Allemand E, Bertozzi I, Candeo N, Marun S, Girolami B
Acta Haematol 2010;123(4):210-4. Epub 2010 Apr 27 doi: 10.1159/000313361. PMID: 20424433


Riano I, Prasongdee K
J Investig Med High Impact Case Rep 2021 Jan-Dec;9:23247096211012187. doi: 10.1177/23247096211012187. PMID: 33940978Free PMC Article
Quail MT
J Pediatr Oncol Nurs 2013 Jul-Aug;30(4):198-204. Epub 2013 Apr 29 doi: 10.1177/1043454213487436. PMID: 23629422


Riano I, Prasongdee K
J Investig Med High Impact Case Rep 2021 Jan-Dec;9:23247096211012187. doi: 10.1177/23247096211012187. PMID: 33940978Free PMC Article

Clinical prediction guides

Poon MC, Moore MR, Castleberry RP, Lurie A, Huang ST, Lehmeyer J
Am J Hematol 1982 May;12(3):261-70. doi: 10.1002/ajh.2830120308. PMID: 6919394

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