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":4,"sourceGroups":{"omim":0,"orphanet":0,"published":4}},"features":[{"hpoId":"HP:0003233","label":"Decreased circulating HDL-C concentration","primary":false},{"hpoId":"HP:0002155","label":"Hypertriglyceridemia","primary":false},{"hpoId":"HP:0001658","label":"Myocardial infarction","primary":false},{"hpoId":"HP:0005181","label":"Premature coronary artery atherosclerosis","primary":false}],"ledeHtml":"Familial HDL deficiency is a condition characterized by low levels of high-density lipoprotei% (HDL) in the blood. HDL is a molecule that transports cholesterol and certain fats called phospholipids through the bloodstream from the body's tissues to the liver. Once in the liver, cholesterol and phospholipids are redistributed to other tissues or removed from the body. HDL is often referred to as "good cholesterol" because high levels of this substance reduce the chances of developing heart and blood vessel (cardiovascular) disease. People with familial HDL deficiency may develop cardiovascular disease at a relatively young age, often before age 50.","mondoId":"MONDO:0011393","records":[{"frequencyKind":"count","key":"a107b19581a9b0950370e36a591e22c85c73e59d00f109afb8bbf87d46b9bcd9","raw":{"aspect":"P","body_system":"metabolic","disease_id":"OMIM:604091","disease_name":"HDL deficiency, familial, 1","evidence":"PCS","frequency_raw":"0/7","hpo_id":"HP:0002155","is_excluded":true,"label":"Hypertriglyceridemia","onset_id":null,"reference":"PMID:30503498","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"count","key":"b82a5d9da100aff261e2c941f070d0d532ff8138dc494d223b27775db803a1a4","raw":{"aspect":"P","body_system":"metabolic","disease_id":"OMIM:604091","disease_name":"HDL deficiency, familial, 1","evidence":"PCS","frequency_raw":"6/7","hpo_id":"HP:0003233","is_excluded":false,"label":"Decreased circulating HDL-C concentration","onset_id":null,"reference":"PMID:30503498","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"reported","key":"c0c3970a7fd2a70cd565be6d90173087bab8cec126f9c5f2f05fb5f3501e8def","raw":{"aspect":"P","body_system":"cardiovascular","disease_id":"OMIM:604091","disease_name":"HDL deficiency, familial, 1","evidence":"PCS","frequency_raw":null,"hpo_id":"HP:0001658","is_excluded":false,"label":"Myocardial infarction","onset_id":null,"reference":"PMID:10431236","source_release":"2026-06-23"},"sourceGroups":["published"]},{"frequencyKind":"count","key":"fe0c07670aa86ad8653e5139ee5354703bf443b6926a4c90b1b7cdbf0bed7a48","raw":{"aspect":"P","body_system":"cardiovascular","disease_id":"OMIM:604091","disease_name":"HDL deficiency, familial, 1","evidence":"PCS","frequency_raw":"2/4","hpo_id":"HP:0005181","is_excluded":false,"label":"Premature coronary artery atherosclerosis","onset_id":null,"reference":"PMID:7627690","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":"Mutations in the ABCA1 gene or the APOA1 gene cause familial HDL deficiency. The proteins produced from these genes work together to remove cholesterol and phospholipids from cells.
The ABCA1 gene provides instructions for making a protein that removes cholesterol and phospholipids from cells by moving them across the cell membrane. The movement of these substances across the membrane is enhanced by another protein called apolipoprotein A-I (apoA-I), which is produced by the APOA1 gene. Once outside the cell, the cholesterol and phospholipids combine with apoA-I to form HDL. ApoA-I also triggers a reaction that converts cholesterol to a form that can be fully integrated into HDL and transported through the bloodstream.
ABCA1 gene mutations and some APOA1 gene mutations prevent the release of cholesterol and phospholipids from cells. Other mutations in the APOA1 gene reduce the protein's ability to stimulate the conversion of cholesterol. These ABCA1 and APOA1 gene mutations decrease the amount of cholesterol or phospholipids available to form HDL, resulting in low levels of HDL in the blood. A shortage (deficiency) of HDL is believed to increase the risk of cardiovascular disease.
","key":"forms","title":"What causes Familial HDL deficiency?"},{"bodyHtml":"Severely reduced levels of HDL in the blood is a characteristic feature of a related disorder called Tangier disease. People with Tangier disease have additional signs and symptoms, such as disturbances in nerve function; enlarged, orange-colored tonsils; and clouding of the clear covering of the eye (corneal clouding). However, people with familial HDL deficiency do not have these additional features.
Source: MedlinePlus Genetics
","key":"overview","title":"Condition overview"}],"sharedSources":[],"slug":"familial-hdl-deficiency","sourceDocuments":[{"name":"Familial HDL deficiency","reviewed":"2012-11","sections":{"causes":{"fetchedAt":"2026-10-20T20:21:22.932792+00:00","label":"Causes","pageSha256":"37042e48ed56603023871d76edd230a91aaa027c4e3fb8140cece24114546056","sourceUrl":"https://medlineplus.gov/genetics/condition/familial-hdl-deficiency/#causes","status":"available"}},"source_release":"2026-10-01","url":"https://medlineplus.gov/genetics/condition/familial-hdl-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":"Familial HDL deficiency"},"schemaVersion":1}