👤 Gilberto Vargas-Alarcón

We evaluated whether cholesteryl ester transfer protein (CETP) gene polymorphisms are associated with the presence of coronary artery disease (CAD) and/or restenosis in patients with coronary stent. Two polymorphisms of the CETP gene [-971 A/G (rs4783961), and Taq1B A/G (rs708272)] were genotyped by 5'exonuclease TaqMan assays in 219 patients with CAD (66 patients with restenosis and 153 without restenosis) and 607 control individuals. The distribution of polymorphisms was similar in patients with and without restenosis. However, when the whole group of patients (with and without restenosis) was compared to healthy controls, under dominant model, the G allele of the Taq1B A/G polymorphism was associated with increased risk of CAD (odds ratio [OR] = 1.48, pCDom = 0.032). In the same way, under codominant, dominant, and additive models, the A allele of the -971 A/G polymorphisms was associated with an increased risk of developing CAD (OR = 2.03, pCCo-dom = 0.022, OR = 1.83, pCDom = 0.008, and OR = 1.39, pCAdd = 0.011, respectively). In addition, the linkage disequilibrium showed that the "AG" haplotype was associated with increased risk of developing CAD (OR = 1.28, p = 0.03). This study demonstrates that CETP Taq1B A/G and CETP -971 A/G polymorphisms are associated with an increased risk of developing CAD, but no association with restenosis was observed. Show less

Low HDL-C (high-density lipoprotein cholesterol) is the most frequent dyslipidemia in Mexicans, but few studies have examined the underlying genetic basis. Our purpose was to identify genetic variants associated with HDL-C levels and cardiovascular risk in the Mexican population. A genome-wide association studies for HDL-C levels in 2335 Mexicans, identified four loci associated with genome-wide significance: CETP, ABCA1, LIPC, and SIDT2. The SIDT2 missense Val636Ile variant was associated with HDL-C levels and was replicated in 3 independent cohorts (P=5.9×10−18 in the conjoint analysis). The SIDT2/Val636Ile variant is more frequent in Native American and derived populations than in other ethnic groups. This variant was also associated with increased ApoA1 and glycerophospholipid serum levels, decreased LDL-C (low-density lipoprotein cholesterol) and ApoB levels, and a lower risk of premature CAD. Because SIDT2 was previously identified as a protein involved in sterol transport, we tested whether the SIDT2/Ile636 protein affected this function using an in vitro site-directed mutagenesis approach. The SIDT2/Ile636 protein showed increased uptake of the cholesterol analog dehydroergosterol, suggesting this variant affects function. Finally, liver transcriptome data from humans and the Hybrid Mouse Diversity Panel are consistent with the involvement of SIDT2 in lipid and lipoprotein metabolism. This is the first genome-wide association study for HDL-C levels seeking associations with coronary artery disease in the Mexican population. Our findings provide new insight into the genetic architecture of HDL-C and highlight SIDT2 as a new player in cholesterol and lipoprotein metabolism in humans. Show less

Obesity, a chronic low-grade inflammation metabolic abnormality, is related to high proinflammatory cytokines concentrations. Epstein-Barr virus-induced gene 3 (EBI3) encodes for the EBI3 beta subunit that constitutes interleukin (IL) 27 and 35. Our objective was to assess the association of three EBI3 single nucleotide polymorphisms (SNPs) with the presence of central obesity in a group of Mexican subjects. The rs428253, rs4740, and rs4905 EBI3 SNPs were genotyped in 1323 individuals (1092 central obese and 231 non-central obese). We also analyzed IL-6, IL-27, and IL-35 concentrations. Under different models, the rs4740 (OR = 0.384, P Show less