Single nucleotide polymorphisms (SNPs) in the noncoding region of 9p21 have been associated with cardiovascular disease (CVD), but the mechanisms by which these genetic variants contribute to the pathogenesis of CVD remain unknown since no annotated proteins are present in this region of DNA. The objective of the current study was to determine if 9p21 genotypes are associated with distinct plasma proteins in young adults. Subjects were 1611 young adults aged 20-29 years from the Toronto Nutrigenomics and Health Study (1098 females and 513 males). DNA was isolated from fasting blood to analyze four SNPs in 9p21 (rs2383206, rs10757274, rs10757278, and rs1333049). Abundant plasma proteins ( n = 54) were measured using liquid chromatography multiple reaction monitoring mass spectrometry. Analysis of covariance was used to determine differences in plasma proteins between genotypes. In Caucasians ( n = 524), four SNPs were associated with apolipoprotein E and two with haptoglobin-β-chain concentration. In East Asians ( n = 388), three SNPs were associated with α-1b-Glycoprotein, two with apolipoprotein B-100, one with apolipoprotein E and one with haptoglobin-β-chain concentration. In South Asians ( n = 117), one SNP was associated with apolipoprotein B-100 concentration. Our findings suggest that 9p21 genotypes may play a role in various pathophysiological pathways that contribute to risk of CVD in early adulthood that might be distinct among different ethnocultural groups.
Keywords: 9p21; Apolipoprotein E; Apolipoprotein B-100; CVD; Haptoglobin-β-Chain; genetics; multiethnic; multiple reaction monitoring (MRM); proteomics; α-1b-Glycoprotein.