ATP-binding cassette transporter A1 gene I823M polymorphism affects plasma high-density lipoprotein cholesterol level and modifies the effect of low high-density lipoprotein cholesterol on the risk of coronary artery disease

Effects of ABCA1 gene polymorphisms on risk factors, susceptibility and severity of coronary artery disease

BACKGROUND

The relationships between the rs1800976, rs4149313 and rs2230806 polymorphisms in ATP binding cassette protein A1 and severity of coronary artery disease (CAD) remain unclear.

METHODS

Four hundred and forty-two patients with CAD and 217 CAD-free subjects were enrolled in this study. The rs1800976, rs4149313 and rs2230806 polymorphisms were genotyped by PCR-RFLP. Severity of CAD was evaluated by Gensini score system, number of stenotic coronary vessels and extent of coronary stenosis.

RESULTS

C allele of the rs1800976 polymorphism, G allele of the rs4149313 polymorphism and A allele of the rs2230806 polymorphism were found to be risk alleles for CAD (p<0.05 for all). In patients with CAD, C allele of the rs1800976 polymorphism was associated with high levels of hypersensitive C reactive protein (hs-CRP) and cystatin c (CysC), and its frequency increased with percentiles of Gensini score, number of stenotic coronary vessels and extent of coronary stenosis (p<0.05 for all). The subjects with GA genotype of the rs4149313 polymorphism had higher levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), apolipoprotein B and hs-CRP than those with AA genotype (p<0.05 for all). The subjects with AA genotype of the rs2230806 polymorphism had higher levels of TC, LDL-C and uric acid than those with GA genotype (p<0.05 for all). No associations between the rs4149313 or rs2230806 polymorphism and severity of CAD were detected.

CONCLUSIONS

The rs1800976 polymorphism is significantly associated with the occurrence and severity of CAD, which is possibly mediated by hs-CRP and CysC.

Single nucleotide polymorphism rs3774261 in the AdipoQ gene is associated with the risk of coronary heart disease (CHD) in Northeast Han Chinese population: a case-control study

Background

Coronary Heart Disease (CHD) is one of the leading causes of death in the world with a projected global 82 million DALYs by 2020. Genetic and environmental factors contribute to CHD development. Here, the authors investigate the association between CHD risk and three Single Nucleotide Polymorphisms (SNPs) in the AdipoQ gene (rs3774261, rs1063537 and rs2082940); and the interaction of this association with environmental factors, in Northeast Han Chinese population.

Methods

Using a case–control study design, 1514 participants (754 cases and 760 controls) were investigated. Three variants in the AdipoQ gene (rs3774261, rs1063537 and rs2082940) were selected and genotyped. The online SNPstats program and SPSS 21.0 software were used for data analyses.

Results

The authors found that the rs3774261G allele is associated with the risk of CHD but that the rs2082940T allele protects against CHD. No significant association was found between rs1063537 and CHD risk. The study also found significant interactions between triglyceride levels and the SNPs studied (P < 0.0001 for rs3774261, P = 0.014 for rs1063537, and P = 0.031 for rs2082940).

Conclusions

Variations in AdipoQ gene can protect against CHD (as with rs2082940T) or associated with CHD risk (as with rs3774261G) in Northeast Han Chinese – findings that will help shed light on the reported conflicting roles of AdipoQ in cardiovascular diseases. Serum triglycerides levels also interact in the AdipoQ – CHD association, thus further highlighting the roles environmental factors play in the genetic aspect of diseases.

Influence of ATP-binding cassette transporter 1 R219K and M883I polymorphisms on development of atherosclerosis: a meta-analysis of 58 studies

Background

Numerous epidemiological studies have evaluated the associations between ATP-binding cassette transporter 1 (ABCA1) R219K (rs2230806) and M883I (rs4149313) polymorphisms and atherosclerosis (AS), but results remain controversial. The purpose of the present study is to investigate whether these two polymorphisms facilitate the susceptibility to AS using a meta-analysis.

Methods

PubMed, Embase, Web of Science, Medline, Cochrane database, Clinicaltrials.gov, Current Controlled Trials, Chinese Clinical Trial Registry, CBMdisc, CNKI, Google Scholar and Baidu Library were searched to get the genetic association studies. All statistical analyses were done with Stata 11.0.

Results

Forty-seven articles involving 58 studies were included in the final meta-analysis. For the ABCA1 R219K polymorphism, 42 studies involving 12,551 AS cases and 19,548 controls were combined showing significant association between this variant and AS risk (for K allele vs. R allele: OR = 0.77, 95% CI = 0.71–0.84, P<0.01; for K/K vs. R/R: OR = 0.60, 95% CI = 0.51–0.71, P<0.01; for K/K vs. R/K+R/R: OR = 0.69, 95% CI = 0.60–0.80, P<0.01; for K/K+R/K vs. R/R: OR = 0.74, 95% CI = 0.66–0.83, P<0.01). For the ABCA1 M883I polymorphism, 16 studies involving 4,224 AS cases and 3,462 controls were combined. There was also significant association between the variant and AS risk (for I allele vs. M allele: OR = 0.85, 95% CI = 0.77–0.95, P<0.01).

Conclusions

The present meta-analysis suggested that the ABCA1 R219K and M883I polymorphisms were associated with the susceptibility to AS. However, due to the high heterogeneity in the meta-analysis, the results should be interpreted with caution.

Genetic variation of the ATP-binding cassette transporter A1 and susceptibility to coronary heart disease

ATP-binding cassette transporter A1 (ABCA1) is a member of a superfamily of membrane proteins that has attracted considerable attention as a candidate gene for coronary heart disease (CHD) based on its enzyme function as a key factor in regulating plasma HDL-C and apo A-I metabolism. It has been suggested that polymorphisms in the ABCA1 gene are risk factors for CHD, but a large number of studies have reported apparently conflicting results. To investigate this inconsistency and derive a more precise estimation of the relationship, a meta-analysis of 14,040 cases and 28,607 controls from 31 published case-control studies was performed. Five potential sources of heterogeneity including ethnicity, source of control, sample size, HWE status and genotyping method of study were also assessed. Overall, significantly decreased CHD risk was associated with 219K allele of R219K polymorphism when all studies were pooled into the meta-analysis. In the subgroup analysis by ethnicity, significantly decreased risks were found in Asians and other ethnic population for the polymorphism in all genetic models; while no significant associations were found among Caucasians. When stratified by source of controls, both population and hospital based studies get consistent positive results. However, no significant results were observed for I883M polymorphism of ABCA1 in all genetic models. In conclusion, this meta-analysis suggests that K allele of ABCA1 R219K polymorphism is a protective factor associated with decreased CHD susceptibility, but these associations vary in different ethnic populations.

Effect of ABCA1 mutations on risk for myocardial infarction

The adenosine triphosphate-binding cassette A1 (ABCA1) gene codes for a cellular phospholipid and cholesterol transporter that mediates the initial and essential step in high-density lipoprotein (HDL) biogenesis: the formation of nascent HDL particles. Mutations at the ABCA1 gene locus cause severe familial HDL deficiency and, in the homozygous form, cause Tangier disease. Several studies have investigated the influence of ABCA1 variation on lipid metabolism and coronary heart disease, but they have resulted in controversial and inconsistent results. Genetic variability at the ABCA1 gene has also been associated with increased risk of myocardial infarction. In one study, this association was independent of HDL cholesterol levels, raising the possibility that the measurement of HDL cholesterol levels may not provide adequate information on the functional roles of HDL particles. Nevertheless, genomic screening for complex diseases, such as coronary heart disease, and HDL deficiency in particular, may not add additional information to that gained from conventional global cardiovascular risk stratification.