APOB
LOCUS ID338
GENE_SYMBOLAPOB
GENE NAMEapolipoprotein B
SYNONYMNSFLDB, LDLCQ4, apoB-48, apoB-100
CHROMOSOME2
HOMOLOGENE ID328
microRNAsNANA
GENE SUMMARY
This gene product is the main apolipoprotein of chylomicrons and low density lipoproteins. It occurs in plasma as two main isoforms, apoB-48 and apoB-100the former is synthesized exclusively in the gut and the latter in the liver. The intestinal and the hepatic forms of apoB are encoded by a single gene from a single, very long mR. The two isoforms share a common N-terminal sequence. The shorter apoB-48 protein is produced after R editing of the apoB-100 transcript at residue 2180 (CAA->UAA), resulting in the creation of a stop codon, and early translation termination. Mutations in this gene or its regulatory region cause hypobetalipoproteinemia, normotriglyceridemic hypobetalipoproteinemia, and hypercholesterolemia due to ligand-defective apoB, diseases affecting plasma cholesterol and apoB levels. [provided by RefSeq, Jul 2008]

OBSERVATIONS

Complication Evidence PMID
Cardiovascular1. lipoprotein abnormalities characteristic of type 2 diabetes (low HDL cholesterol, high LDL triglycerides or apolipoprotein B levels, and low LDL cholesterol/apolipoprotein B ratio as a marker for LDL size) were predictive of cardiovascular death in these analyses.9802734
Retinopathy1. ApoAI and apoB and the apoB-to-apoAI ratio were significantly and independently associated with diabetic retinopathy and diabetic retinopathy severity and improved the ability to discriminate diabetic retinopathy by 8%. Serum apolipoprotein levels may therefore be stronger biomarkers of diabetic retinopathy than traditional lipid measures.21270203
Neuropathy1.In summary, the Ox-LDL/apoB ratio was associated with macrovascular disease and peripheral neuropathy in Japanese patients with type 2 diabetes. Increased Ox-LDL/apoB may result, at least partly, from reduced serum antioxidant capacity in the diabetic state, including the attenuation of PON1 action. Increased Ox-LDL/apoB could be a significant marker for susceptibility to vascular complications in diabetic patients.15015140