Association between rs2200733 and rs7193343 genetic variants and atrial fibrillation in a Spanish population, and meta-analysis of previous studies

Genotype-phenotype associations in atrial fibrillation: meta-analysis

PURPOSE

Genome-wide association studies have identified several single-nucleotide polymorphisms (SNPs) associated with atrial fibrillation (AF). The relationship between SNPs and the incidence of stroke, heart failure, and the recurrence rate of AF after cardioversion has been reported. This meta-analysis focuses on the genotype-phenotype associations in AF.

METHODS

We searched PubMed/Medline and Embase for literature providing the phenotypic parameters and genotypes of RS10033464, RS13376333, RS2106261, RS2200733, and RS7193343. We selected literature published in English and reviewed the full text of included studies to perform a meta-analysis.

RESULTS

Fifteen papers, and 7034 patients with AF, were included. The mean risk gene frequency of the investigated variants was between 12 and 43%. The mean age of patients was between 50 and 70 and 70-80% of them were male. The stroke and heart failure frequencies in AF patients with RS2200733 were 10 and 7%, respectively. There was no significant difference in left ventricular ejection fraction and left ventricular end-diastolic diameter for all risk genotypes. For the AF recurrence after cardioversion treatment with direct current electric conversion, catheter ablation therapy, and anti-arrhythmic drugs. The early AF recurrence rate was 46% in RS10033464 and RS13376333 patients, and the late AF recurrence rate was 53% in RS2200733 patients.

CONCLUSIONS

Pooled analysis showed a significantly high prevalence of stroke (10%) in RS2200733 AF patients. AF patients with the studied SNPs had preserved left ventricular systolic function (i.e., ejection fraction greater than 50%). AF patients with RS10033464 presented larger left atrium diameter (44 mm (95% CI 42.02-45.98)) than those with other SNPs. The late AF recurrence rate was highest in RS2200733 patients (53% (95% CI 0.43-0.64)). This study aids our understanding of the existing genetic findings and the function-altering "strongest" SNPs.

Rs7193343 polymorphism in zinc finger homeobox 3 (ZFHX3) gene and atrial fibrillation: an updated meta-analysis of 10 case-control comparisons

Background

The previous genome-wide studies have shown that rs7193343 single-nucleotide polymorphism (SNP) in zinc finger homeobox 3 (ZFHX3) gene correlate with risk of atrial fibrillation (AF). However, the distribution of this SNP differs significantly among various populations. The present study was to investigate whether combined evidence shows the association between ZFHX3 rs7193343 SNP and the risk of AF in various populations.

Methods

A systematic search of all studies published through Dec 2014 was conducted using the Medline, Embase, WanFang, ScienceDirect, CNKI, and OVID databases. The case-control studies that evaluated an association between rs7193343 SNP and risk of AF were identified. The association between the ZFHX3 rs7193343 SNP and AF susceptibility was assessed using genetic models.

Results

We collected 10 comparisons from six studies for rs7193343 SNP, including 1037 cases and 4310 controls in Asian, 5583 cases and 38215 controls in Caucasian, and then performed an updated meta-analysis and subgroup analysis based on ethnicity. In overall population, the occurrence of AF was found to be associated with T-allelic of rs7193343 SNP in ZFHX3 (OR =1.17, 95% CI 1.10-1.26). In subgroup analysis, we observed there was significant association between T-allele of rs7193343 and risk of AF in Caucasian subgroups (OR =1.20, 95% CI 1.12-1.30), but no statistically significance (OR = 1.07, 95% CI 0.92-1.24) in Asian population.

Conclusion

In Caucasian population, genetic variant rs7193343 SNP is associated with risk of AF in Caucasian population. However, no association is found in Asian population based on the current evidence. Further studies with larger sample size involving case-control populations with multiple ethnics are still required in the future.