Genetic risk assessment for cardiovascular disease in Azoreans (Portugal): a general population-based study

Abstract

The identification of clinically validated genetic variants contributing to complex disorders raise the possibility to investigate individuals' risk. In this line of research, the present work aimed to assess the genetic risk for cardiovascular disease (CVD) in Azoreans. Genotyping of 19 SNPs - 9 on 9p21, 5 on LDLR and 5 on USF1 - was performed by TaqMan assays on 170 healthy Azorean individuals. Results demonstrate that the most frequent haplotype in 9p21, with a frequency of 41.4%, is TGGGCGCGC, which harbors all risk alleles. Considering haplotype homozygosity data show that females present higher value of homozygosity for both LDLR (13.5%) and USF1 (15.3%), whereas males present higher value for the 9p21 region (8.2%). Interestingly, genetic profile analysis revealed differences in terms of geographic and gender distribution. The Azorean Central group presented a higher risk for atherosclerosis, 2.7 times higher when compared to the Eastern group, while the Eastern group shows 1.5 times higher risk for dyslipidemias. Moreover, Azorean females demonstrated a 4 times higher risk for dyslipidemias when compared to males, whereas males have an increased risk for atherosclerosis. Although allele frequencies in Azoreans were similar to those reported for the HapMap CEU population, the differences in terms of haplotype and genetic profile distribution must be taken in consideration when assessing genetic risk. Taken together, the data here presented evidence for the need to perform biomedical research and epidemiologic analysis in Azoreans with the aim of developing strategies to CVD prevention, health promotion and population education.

Keywords: 9p21; Azores; CAD; CHD; CVD; Cardiovascular disease; Coronary artery disease; Coronary heart disease; GP; Genetic profiles; Genetic risk; HWE; Hardy-Weinberg equilibrium; INE; LD; LDLR; Linkage disequilibrium; Low density lipoprotein receptor; MAF; MI; Minor allele frequency; Myocardial infarction; National Institute of Statistics; ROH; Run of homozygosity; SNP; Single nucleotide polymorphism; USF1; Upstream stimulatory factor 1.