Abetalipoproteinaemia

Abetalipoproteinaemia is a disorder in the synthesis of serum lipoproteins containing apolipoprotein B, for example chylomicrons, VLDL and LDL.

• a rare autosomal recessive metabolic disorder
  • characterized by extremely low levels of plasma cholesterol and triglycerides and almost complete absence of lipoproteins in the density ranges of chylomicrons, VLDL and LDL
• plasma lipids are carried almost entirely in the high density lipoproteins class
• patients suffer from fat malabsorption
  • may present with failure to thrive in early childhood
    • in later childhood patients develop a progressive, ataxic neuropathy and retinopathy, attributed in part to deficiency of fat soluble vitamins, specifically vitamins E and A
• combined high dose vitamin E and vitamin A therapy does confer protection against severe retinal degeneration, fundoscopic and functional retinal changes have been demonstrated, suggesting a role for other factors, including polyunsaturated fatty acid deficiency and ongoing oxidative damage

Reference:

• (1) J. Kane and R. Havel, Disorders of the biogenesis and secretion of lipoproteins containing the B apolipoproteins. In: C. Scriver, A. Beaudet, W. Sly and D. Valle, Editors, The Metabolic and Molecular Bases of Inherited Disease, McGraw-Hill, New York (2001): 2717-2752.
• (2) Granot E, Kohen R.Oxidative stress in abetalipoproteinemia patients receiving long-term vitamin E and vitamin A supplementation, Am. J. Clin. Nutr. 2004;79: 226-230
• (3) Sharp, D. et al. Cloning and gene defects in microsomal triglyceride transfer protein associated with abetalipoproteinaemia. Nature 1993;365: 65-9.