Bassen-Kornzweig syndrome
Definition
Bassen-Kornzweig syndrome is a rare disease passed down through families. The person is unable to fully absorb dietary fats through their intestines.
Alternative Names
Abetalipoproteinemia; Acanthocytosis; Apolipoprotein B deficiency
Causes
Bassen-Kornzweig syndrome is caused by changes in the MTTP gene that tells the body to create lipoproteins (molecules of fat combined with protein). These variants make it hard for the body to properly digest fat and essential vitamins.
Symptoms
Symptoms include:
- Balance and coordination difficulties
- Curvature of spine
- Decreased vision that gets worse over time
- Developmental delay
- Failure to thrive (grow) in infancy
- Muscle weakness
- Poor muscle coordination that usually develops after age 10
- Protruding abdomen
- Slurred speech
- Stool abnormalities, including fatty stools that appear pale in color, frothy stools, and abnormally foul-smelling stools
Exams and Tests
There may be damage to the retina of the eye (retinitis pigmentosa).
Tests that may be done to help diagnose this condition include:
- Apolipoprotein B blood test
- Blood tests to look for vitamin deficiencies (fat-soluble vitamins A, D, E, and K)
- "Burr-cell" malformation of the red cells (acanthocytosis)
- Complete blood count (CBC)
- Cholesterol studies
- Electromyography
- Eye exam
- Nerve conduction velocity
- Stool sample analysis
Genetic testing may be available for genetic variants in the MTTP gene.
Treatment
Treatment involves large doses of vitamin supplements containing fat-soluble vitamins (vitamin A, vitamin D, vitamin E, and vitamin K).
Linoleic acid supplements are also recommended.
People with this condition should talk to a dietitian. Diet changes are needed to prevent stomach problems. This may involve limiting intake of some types of fat.
Supplements of medium-chain triglycerides are taken under the supervision of a health care provider. They should be used with caution, because they may cause liver damage.
Outlook (Prognosis)
How well a person does depends on the amount of brain and nervous system problems.
Possible Complications
Complications may include:
- Blindness
- Mental deterioration
- Loss of function of peripheral nerves, uncoordinated movement (ataxia)
When to Contact a Medical Professional
Contact your provider if your infant or child has symptoms of this disease. Genetic counseling can help families understand the condition and the risks of inheriting it, and learn how to care for the person.
Prevention
High doses of fat-soluble vitamins may slow the progression of some problems, such as retina damage and decreased vision.
References
Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM. Defects in metabolism of lipids. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 104.
Shamir R. Disorders of malabsorption. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 364.
Reviewed By: Anna C. Edens Hurst, MD, MS, Associate Professor in Medical Genetics, The University of Alabama at Birmingham, Birmingham, AL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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