Effect of Polymorphisms in the NADSYN1/DHCR7 Locus (rs12785878 and rs1790349) on Plasma 25-Hydroxyvitamin D Levels and Coronary Artery Disease Incidence

Abstract

BACKGROUND/AIMS: Recent genome-wide association studies have identified the rs1790349 and rs12785878 single-nucleotide polymorphisms (SNPs), present in the NADSYN1/DHCR7 locus, as an influential player on circulating 25-hydroxyvitamin D [25(OH)D] levels, which itself has been linked to various diseases including cardiovascular disease (CVD). This study investigated the association of these SNPs with CVD and 25(OH)D levels. METHODS: Sixty- three male patients with verified coronary artery disease (CAD) were recruited, as well as 31 age- and sex-matched controls. Genotyping was performed by sequencing, whereas plasma 25(OH)D levels were assessed by HPLC-UV. RESULTS: Statistical insignificance was observed in comparing the genotype distribution of patients and controls for both the rs12785878 (NADSYN1) polymorphism (p = 0.097) and the rs1790349 (DHCR7; p = 0.9). Comparison of allelic distributions of rs1790349 and rs12785878 yielded insignificant results (p = 0.7, OR: 0.58-2.6 and p = 0.14, OR: 0.88-2.85, respectively). Taking together patients and controls, both SNPs were found to influence total 25(OH)D levels (p = 0.001 and p < 0.0001) as well as 25(OH)D3 levels only in controls. CONCLUSION: This study further supports the evidence of the ability of the investigated SNPs to predict circulating 25(OH)D levels, nonetheless opposing their use as genetic markers for CAD.