abetalipoproteinemia (Bassen-Kornzweig syndrome)

Epidemiology

rare disorder

Pathology

• acanthocytosis
• biopsy shows fat-laden mucosal cells in well-formed villi
• virtually no circulating apolipoprotein B-containing lipoproteins (chylomicrons, VLDL, LDL, lipoprotein<A>)
• much of the pathology may be due to fat-soluble vitamin deficiency

Genetics

• autosomal recessive
• associated with defects in MTTP gene

Clinical manifestations

• fat malabsorption
  • fat-soluble vitamin deficiency
    • vitamin A deficiency
    • vitamin D deficiency
    • vitamin E deficiency
    • vitamin K deficiency
  • steatorrhea
• neuromuscular abnormalities, spinocerebellar degeneration
• mental retardation
• retinitis pigmentosa
• fat soluble vitamin deficiencies
  • vitamin E, vitamin A, vitamin D

Laboratory

• decreased serum cholesterol & LDL cholesterol
• absence of apolipoprotein B, chylomicrons, VLDL & LDL

Management

• dietary modification
  • restriction of long-chain fatty acids to 15 g per day
  • supplementation with medium-chain triglycerides may be necessary
    • monitor closely to avoid liver toxicity.
• fat-soluble itamin supplementation
  • vitamin E (100-300 mg/kg/day)
  • vitamin A (10,000-25,000 IU/day)
• consults
  • gastroenterologist
  • ophthalmologist
  • neurologist
  • nutritionist

Notes

• distinguish from familial dysbetalipoproteinemia

More general terms

• beta lipoprotein deficiency

Additional terms

• low density lipoprotein (LDL, beta-lipoprotein)

Database

• OMIM: https://mirror.omim.org/entry/200100