Human familial hypobetalipoproteinemia (FHBL) is a genetic disorder, inherited as an autosomal dominant trait, characterized by decreased levels of low density lipoprotein (LDL) cholesterol and apoB. The classical clinical picture of the homozygous patient includes profound hypocholesterolemia with virtual absence of LDL cholesterol and apoB, hypotriglyceridemia, fat malabsorption, clotting abnormalities due to vitamin K deficiency and red cell acanthocytosis [Kane J.P, 1989]. In addition, severe neurologic disorders may became evident after the first decade of life that seem related to vitamin E malabsorption [Muller D.P.R., 1983]. Heterozygous individuals are usually free from symptoms but their LDL cholesterol and apoB concentrations are half the normal value or less.
