Each column keeps its native condition scope. Initial features are displayed alphabetically, not ranked by clinical importance. Counts remain separate, and an empty cell does not mean a feature cannot occur.
"},"coverage":{"countRecords":3,"emptyColumnKeys":[],"hpoRelease":"2026-06-23","narrativeSourceChanges":[],"records":3,"sourceGroups":{"omim":0,"orphanet":0,"published":3}},"features":[{"hpoId":"HP:0001892","label":"Abnormal bleeding","primary":false},{"hpoId":"HP:0034371","label":"Decreased circulating prekallikrein concentration","primary":false},{"hpoId":"HP:0003645","label":"Prolonged partial thromboplastin time","primary":false}],"ledeHtml":"Prekallikrein deficiency is a blood condition that usually causes no health problems. In people with this condition, blood tests show a prolonged activated partial thromboplastin time (PTT), a result that is typically associated with bleeding problems; however, bleeding problems generally do not occur in prekallikrein deficiency. The condition is usually discovered when blood tests are done for other reasons.","mondoId":"MONDO:0044744","records":[{"frequencyKind":"count","key":"90b04f57b006f23be1dbdf3ea2b771559cb287ebfa9a6881938768dcbcbc88b9","raw":{"aspect":"P","body_system":"metabolic","disease_id":"OMIM:612423","disease_name":"Prekallikrein deficiency","evidence":"PCS","frequency_raw":"1/1","hpo_id":"HP:0034371","is_excluded":false,"label":"Decreased circulating prekallikrein concentration","onset_id":null,"reference":"PMID:15461630","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"count","key":"c6f43c294ddb20d5a0eaa4bf014eb5f78122e8aa0124fdb5893f3320c5b4d6f3","raw":{"aspect":"P","body_system":"blood","disease_id":"OMIM:612423","disease_name":"Prekallikrein deficiency","evidence":"PCS","frequency_raw":"0/1","hpo_id":"HP:0001892","is_excluded":true,"label":"Abnormal bleeding","onset_id":null,"reference":"PMID:15461630","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"count","key":"defa600c7b95a6ce129ec82da201c9281f482ec06ab6a39fbe5449d12f72d9d0","raw":{"aspect":"P","body_system":"blood","disease_id":"OMIM:612423","disease_name":"Prekallikrein deficiency","evidence":"PCS","frequency_raw":"1/1","hpo_id":"HP:0003645","is_excluded":false,"label":"Prolonged partial thromboplastin time","onset_id":null,"reference":"PMID:15461630","source_release":"2026-06-23"},"sourceGroups":["published"]}],"referenceLabels":{},"references":{"causeHtml":"","identityNote":"MONDO cross-references identify native condition entries. Ancestor membership does not transfer phenotype values between groups.","importantHtml":""},"sections":[{"bodyHtml":"Prekallikrein deficiency is caused by mutations in the KLKB1 gene, which provides instructions for making a protein called prekallikrein. This protein, when converted to an active form called plasma kallikrein in the blood, is involved in the early stages of blood clotting. Plasma kallikrein plays a role in a process called the intrinsic coagulation pathway (also called the contact activation pathway). This pathway turns on (activates) proteins that are needed later in the clotting process. Blood clots protect the body after an injury by sealing off damaged blood vessels and preventing further blood loss.
The KLKB1 gene mutations that cause prekallikrein deficiency reduce or eliminate functional plasma kallikrein, which likely impairs the intrinsic coagulation pathway. Researchers suggest that this lack (deficiency) of functional plasma kallikrein protein does not generally cause any symptoms because another process called the extrinsic coagulation pathway (also known as the tissue factor pathway) can compensate for the impaired intrinsic coagulation pathway.
","key":"forms","title":"What causes Prekallikrein deficiency?"},{"bodyHtml":"A few people with prekallikrein deficiency have experienced health problems related to blood clotting such as heart attack, stroke, a clot in the deep veins of the arms or legs (deep vein thrombosis), nosebleeds, or excessive bleeding after surgery. However, these are common problems in the general population, and most affected individuals have other risk factors for developing them, so it is unclear whether their occurrence is related to prekallikrein deficiency.
Source: MedlinePlus Genetics
","key":"overview","title":"Condition overview"}],"sharedSources":[],"slug":"prekallikrein-deficiency","sourceDocuments":[{"name":"Prekallikrein deficiency","reviewed":"2014-07","sections":{"causes":{"fetchedAt":"2026-10-20T20:24:22.044210+00:00","label":"Causes","pageSha256":"56f2c5d280befbea85086c09c718eaa57dfd362a2aaaae0c47ed6a8c16c05a36","sourceUrl":"https://medlineplus.gov/genetics/condition/prekallikrein-deficiency/#causes","status":"available"}},"source_release":"2026-10-01","url":"https://medlineplus.gov/genetics/condition/prekallikrein-deficiency"}],"sourceNote":"MedlinePlus descriptions and Causes; original HPO annotations.","takeawayHtml":"Cause explanations are from MedlinePlus Genetics. Feature values below retain their original sources and patient groups.","title":"Prekallikrein deficiency"},"schemaVersion":1}