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Norum disease

MedGen UID:
Concept ID:
Disease or Syndrome
Synonym: Familial lecithin cholesterol acyltransferase deficiency
SNOMED CT: Familial lecithin cholesterol acyltransferase deficiency (1264565005); Complete LCAT deficiency (1264565005); Norum disease (1264565005); Complete LCAT (lecithin-cholesterol acyltransferase) deficiency (1264565005)
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).
Not genetically inherited
MedGen UID:
Concept ID:
Source: Orphanet
clinical entity without genetic inheritance.
Gene (location): LCAT (16q22.1)
Monarch Initiative: MONDO:0009515
OMIM®: 245900
Orphanet: ORPHA79293


Complete LCAT deficiency is a disorder that primarily affects the eyes and kidneys.

In complete LCAT deficiency, the clear front surface of the eyes (the corneas) gradually becomes cloudy. The cloudiness, which generally first appears in early childhood, consists of small grayish dots of cholesterol (opacities) distributed across the corneas. Cholesterol is a waxy, fat-like substance that is produced in the body and obtained from foods that come from animals; it aids in many functions of the body but can become harmful in excessive amounts. As complete LCAT deficiency progresses, the corneal cloudiness worsens and can lead to severely impaired vision.

People with complete LCAT deficiency often have kidney disease that begins in adolescence or early adulthood. The kidney problems get worse over time and may eventually lead to kidney failure. Individuals with this disorder also usually have a condition known as hemolytic anemia, in which red blood cells are broken down (undergo hemolysis) prematurely, resulting in a shortage of red blood cells (anemia). Anemia can cause pale skin, weakness, fatigue, and more serious complications.

Other features of complete LCAT deficiency that occur in some affected individuals include enlargement of the liver (hepatomegaly), spleen (splenomegaly), or lymph nodes (lymphadenopathy) or an accumulation of fatty deposits on the artery walls (atherosclerosis). [from MedlinePlus Genetics]

Clinical features

From HPO
MedGen UID:
Concept ID:
Increased levels of protein in the urine.
Renal insufficiency
MedGen UID:
Concept ID:
Disease or Syndrome
A reduction in the level of performance of the kidneys in areas of function comprising the concentration of urine, removal of wastes, the maintenance of electrolyte balance, homeostasis of blood pressure, and calcium metabolism.
Foam cells
MedGen UID:
Concept ID:
The presence of foam cells, a type of macrophage that localizes to fatty deposits on blood vessel walls, where they ingest low-density lipoproteins and become laden with lipids, giving them a foamy appearance.
Hemolytic anemia
MedGen UID:
Concept ID:
Disease or Syndrome
A type of anemia caused by premature destruction of red blood cells (hemolysis).
Normochromic anemia
MedGen UID:
Concept ID:
Decreased HDL cholesterol concentration
MedGen UID:
Concept ID:
An decreased concentration of high-density lipoprotein cholesterol in the blood.
MedGen UID:
Concept ID:
An abnormal increase in the level of triglycerides in the blood.
Decreased lecithin cholesterol acyl transferase level
MedGen UID:
Concept ID:
Reduced level of the enzyme lecithin cholesterol acyl transferase.
Arcus senilis
MedGen UID:
Concept ID:
A hazy, grayish-white ring about 2 mm in width located close to but separated from the limbus (the corneoscleral junction). Corneal arcus generally occurs bilaterally, and is related to lipid deposition in the cornea. Corneal arcus can occur in elderly persons as a part of the aging process but may be associated with hypercholesterolemia in people under the age of 50 years.

Professional guidelines


Freeman LA, Shamburek RD, Sampson ML, Neufeld EB, Sato M, Karathanasis SK, Remaley AT
J Lipid Res 2019 May;60(5):1050-1057. Epub 2019 Feb 26 doi: 10.1194/jlr.D090233. PMID: 30808683Free PMC Article
Kuroda M, Saito Y, Aso M, Yokote K
Chem Pharm Bull (Tokyo) 2018;66(3):217-224. doi: 10.1248/cpb.c17-00786. PMID: 29491255
Schaefer EJ, Anthanont P, Diffenderfer MR, Polisecki E, Asztalos BF
Prog Cardiovasc Dis 2016 Sep-Oct;59(2):97-106. Epub 2016 Aug 24 doi: 10.1016/j.pcad.2016.08.006. PMID: 27565770Free PMC Article

Recent clinical studies


Goñi Ros N, González-Tarancón R, Sienes Bailo P, Salvador-Ruperez E, Puzo Bayod M, Puzo Foncillas J
Acta Clin Belg 2022 Dec;77(6):970-975. Epub 2021 Nov 18 doi: 10.1080/17843286.2021.2007598. PMID: 34789074

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