The Study of rs693 and rs515135 in APOB in People with Familial Hypercholestrolemia

Document Type : Original Article


1 Department of Biology, Science Faculty, Science and Research Branch, Islamic Azad University, Tehran, Iran

2 Department of Medical Genetics, National Institute for Genetic Engineering and Biotechnology, Tehran, Iran


APOB-related familial hypercholesterolemia (FH) is the most common hereditary hyperchlosterolemia with an autosomal dominant pattern. A number of APOB variants are the most important risk factors for hyperchlosterolemia. APOB is a large glycoprotein that plays an important role in the metabolism of lipoproteins in the human body. Small changes in the structure and function of APOB can cause major problems in lipid metabolism. Two forms of APOB are produced by an editing process of gene replication. APOB48 is required for the production of chylomicrons in the small intestine and APOB100 is essential in liver for the production of very low density lipoprotein (VLDL) and is also a ligand for LDL receptor (LDLR) that mediates LDL endocytosis.
Materials and Methods
In this case-control study, rs693 (in exon 26 of APOB) and rs515135 (5 'end of APOB) single nucleotide polymorphisms (SNPs) were analyzed in 120 cases of familial hypercholesterolemia and 120 controls. Both SNPs were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) where PCR products were digested with specific restriction enzymes recognising each single nucleotide polymorphism.
This study was analyzed by odds-ratio (OR) and its 95% confidence interval (CI) to examine the association of the two SNPs with familial hypercholostermia susceptibility. Statistical analysis showed that both SNPs were in Hardy- Weinberg equilibrium.
We found no significant relationship between rs515135 and familiar hypercholesterolemia. However, there was a significant association between the C allele of rs693 and high familial cholesterol levels. Furthermore, it seems the dominant model of T allele occurrence has a protective role in emergence of disease.