Although the association between the apolipoprotein A5 (APOA5) genetic variants and hypertriglyceridemia has been extensively studied, there have been few studies, particularly in children and adolescents, on the association between APOA5 genetic variants and obesity or non-high-density lipoprotein cholesterol (non-HDL-C) levels.
We describe the clinical features and genetic analysis of three patients with severe hypertriglyceridaemia including novel mutations LPL c.464T>C (p.Leu155Pro) and APOA5 c.823C>T (p.Gln275*).
Using a Mendelian randomization approach, we tested whether genetically increased remnant cholesterol in hypertriglyceridaemia due to genetic variation in the apolipoprotein A5 gene (APOA5) associates with an increased risk of myocardial infarction (MI).
Finally, to explore the possible structural consequences of these mutations, we developed a three-dimensional model of full-length, lipid-free human apoA-V. A complex, wide array of impairments was found in each of the three mutants, suggesting that the specific residues affected are critical structural determinants for apoA-V function in lipoprotein metabolism and, therefore, that these APOA5 mutations are a direct cause of hypertriglyceridemia.
Various studies have identified a number of common (APOA5 c.56C>G; p.S19W; rs 3135506 ) and rare variants in the APOA5 gene in individuals with hypertriglyceridemia.
Finally, comprehensive resequencing studies show a burden of rare variants in some of these same genes - namely in LPL, GCKR, APOB and APOA5 - in HTG patients compared to normolipidemic controls.
Japanese or Korean individuals with the C allele of APOA5 and the T allele of BTN2A1 had a 2.05- or 1.92-fold increased risk for hypertriglyceridemia and a 1.82- or 1.56-fold increased risk for hypo-HDL-cholesterolemia, respectively, compared to those with the TT genotype of APOA5 and the CC genotype of BTN2A1.
The identification of new mutations still relies on the direct sequencing of APOA5 gene of patients with hypertriglyceridemia with an unusual pattern, individually or in huge resequencing studies.
In contrast, common complex HTG results from the cumulative influence of small-effect variants (single nucleotide polymorphisms) in genes such as APOA5, GCKR, LPL, and APOB.
Stepwise positive association between APOA5 minor allele frequencies and increasing plasma triglyceride quartiles in random patients with hypertriglyceridemia of unclarified origin.
We investigated whether apoA-V complexed with phospholipid in the form of a reconstituted high-density lipoprotein (rHDL) has potential utility as a therapeutic agent for treatment of hypertriglyceridemia (HTG) when delivered intravenously.