Bassen-Kornzweig syndrome

Alternative names 
Abetalipoproteinemia; Acanthocytosis; Apolipoprotein B deficiency

Bassen-Kornzweig syndrome is a rare, inherited disease characterized by the inability to fully absorb dietary fats through the gut. It results in fatty stools, diarrhea, failure to thrive in infancy, and problems with nerves.

Causes, incidence, and risk factors

Bassen-Kornzweig syndrome is an autosomal recessive inherited disorder that affects both sexes, but predominantly males (70%). It is due to mutations in one of two genes: apolipoprotein B (APOB) or microsomal triglyceride transfer protein (MTP).

The syndrome causes the body not to make lipoproteins (molecules of fat combined with protein) including low-density lipoproteins (LDL), very-low-density lipoproteins (VLDL), and chylomicrons (small molecules of fat in the blood).

People with this disease are unable to properly digest fat, and have underdeveloped nerves (neuropathy), poor muscle coordination (ataxia), and other nerve disorders.


  • Failure to thrive (grow) in infancy  
  • Fatty stools that appear pale in color  
  • Frothy stools  
  • Abnormally foul-smelling stools  
  • Protruding abdomen  
  • Developmental delay  
  • Poor muscle coordination that usually develops after age 10  
  • Muscle weakness  
  • Slurred speech  
  • Curvature of spine  
  • Progressive decreased vision  
  • Balance and coordination difficulties

Signs and tests

  • CBC (complete blood count) that shows abnormally shaped red blood cells (thorny appearance)  
  • Cholesterol studies, including total cholesterol that shows low levels of VLDL and LDL  
  • Stool collection that shows elevated fat levels  
  • Low levels of fat-soluble vitamins such as vitamins A, D, E, or K  
  • Ophthalmology exam showing retinal degeneration  
  • Absent or low apolipoprotein B levels in blood  
  • Genetic testing may be available for mutations in the APOB or MTP genes  
  • EMG or nerve conduction velocity testing may show demyelination of peripheral nerves


Consult a nutritionist or other medical professional for dietary instruction. Large doses of vitamin supplements containing the fat-soluble vitamins (vitamin A, vitamin D, vitamin E and vitamin K) are given.

To avoid intestinal symptoms, avoid eating long-chain triglycerides. Thus, the diet should contain no more than 5 ounces of lean meat, fish, or poultry per day. Use skim milk instead of whole milk.

Since a certain amount of fat is needed for normal growth and development in all people, medium chain triglycerides are alternatively used as the major source of fat in the diet. These are absorbed from the gut differently than other fats, and thus avoid the intestinal symptoms. Medium chain triglycerides are taken as a dietary supplement, typically under the supervision of a physician or nutritionist.

Expectations (prognosis)

The outcome is related to the degree and progression of neurological and visual problems. Severe forms of the disease lead to irreversible neurologic disease before age 30.


  • Blindness  
  • Mental deterioration  
  • Loss of function of peripheral nerves, ataxia

Calling your health care provider
Call if your infant or child exhibits symptoms of this disease.

High doses of fat soluble vitamins may be able to slow progression of some problems such as degeneration of the retina and decreased vision.

Johns Hopkins patient information

Last revised: December 5, 2012
by Potos A. Aagen, M.D.

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