High Quality Content by WIKIPEDIA articles! Abetalipoproteinemia, or Bassen-Kornzweig syndrome, is a rare autosomal recessive disorder that interferes with the normal absorption of fat and fat-soluble vitamins from food. It is caused by a deficiency of apolipoprotein B-48 and B-100, which are used in the synthesis and exportation of chylomicrons and VLDL respectively. It is not to be confused with familial dysbetalipoproteinemia.