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Genetic and Rare Diseases Information Center (GARD)

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Norum disease

Other Names for this Disease
  • LCAT deficiency
  • Lecithin cholesterol acyltransferase deficiency
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Your Question

I have been diagnosed with Norum disease, a condition also known as lecithin cholesterol acyltransferase (LCAT) deficiency. I would appreciate any information that you could provide and post about this disease, as three generations of my family have been identified with it.

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What is Norum disease?

Norum disease is an autosomal recessive disorder of lipoprotein metabolism that causes a typical triad of diffuse corneal opacities, target cell hemolytic anemia, and proteinuria with renal (kidney) failure.[1][2] Two clinical forms are recognized: familial LCAT deficiency and fish-eye disease. Familial LCAT deficiency is associated with a complete absence of alpha and beta LCAT activities and results in esterification anomalies involving both HDL (alpha-LCAT activity) and LDL (beta-LCAT activity).[2]
Last updated: 9/10/2009

What are the symptoms of Norum disease?

Norum disease is marked by low plasma HDL levels and corneal clouding due to accumulation of cholesterol deposits in the cornea ('fish-eye'). Corneal opacity is often present at birth, beginning at the periphery of the cornea and progressing gradually to the center. Hemolytic anemia, and proteinuria are other common findings.[3] This condition may also present with:[4]

Last updated: 9/8/2009

What causes Norum disease?

Norum disease is caused by defects in the LCAT gene.[2] The clinical manifestations of LCAT deficiency are probably due to a defect in LCAT-mediated cholesterol ester formation and, therefore, accumulation of unesterified cholesterol in certain tissues, such as the cornea, kidneys, and erythrocytes (red blood cells).[4]
Last updated: 9/8/2009

How is Norum disease inherited?

Norum disease is transmitted as an autosomal recessive trait, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.[1][4] Sporadic cases have also been reported.[3]
Last updated: 9/8/2009

How might Norum disease be treated?

Symptomatic treatment for anemia, renal insufficiency, and atherosclerosis is indicated.[5]

  • LCAT gene therapy or liver transplantation theoretically would be a treatment of choice to correct the underlying pathophysiology, but neither procedure has been reported.
  • Short-term whole blood or plasma transfusion has been tried to replace the LCAT enzyme in some patients with familial LCAT deficiency, but it did not correct anemia, proteinuria, or lipoprotein abnormalities.
  • Renal replacement by dialysis is necessary in those individuals who develop kidney failure.
  • Kidney transplantation is indicated in patients with familial LCAT deficiency and renal failure.
  • Corneal transplantation is indicated in patients with corneal opacities with severely reduced vision.
  • Restriction of fat intake may be advisable in patients with familial LCAT deficiency, but no evidence supports its potential benefits.
  • Because of the small but measurable risk of atherosclerosis in persons with LCAT deficiency, exercise, under the guidance of a physician, theoretically would have a role in prevention of this complication.
Last updated: 9/8/2009

What is the prognosis for individuals with Norum disease?

The prognosis for individuals with Norum disease depends on the extent to which the disease affects renal function: the accumulation of abnormal lipoproteins (LpX) in the kidneys may lead to renal insufficiency.[3]
Last updated: 9/8/2009