FUNCTIONAL CHARACTERIZATION OF NOVEL AMINO ACID VARIANTS IN APOB IN FAMILIAL HYPOBETALIPOPROTEINEMIA

Introduction. Familial Hypobetalipoproteinemia (FHBL) is a codominant disorder characterized by reduced levels of LDL and apolipoprotein B (apoB) in plasma. In approximately 50% of FHBL cases is due to mutations in APOB gene resulting in truncated apoBs of various size. Only a few missense mutations have been reported so far as the cause of FHBL. In vitro studies have shown that these mutations induce retention of the mutant apoB in the endoplasmic reticulum and impair the secretion of apoB-containing lipoproteins. We identi ed two novel amino acid variants (Thr26-27del and Tyr102Cys) located in the N-terminal 1000 amino acids of mature apoB in two hypocholesterolemic blood donors. Methods.…