PSRC1, CELSR2, and SORT1 Liver Expression Is Associated with a CAD Risk Allele and Plasma LDL Cholesterol Levels

The CAD risk allele for SNP rs599839 was established in a previous WTCCC study [16] (lilac panel). In the HLC, this same SNP is strongly associated with PSRC1, CELSR2, and SORT1 expression, with the CAD risk allele associated with lower relative expression (pink panel). In the BXH/wt cross designed to study metabolic traits that increase cardiovascular risk (green panel), all three of these expression traits were strongly correlated with plasma LDL cholesterol levels, a major CAD risk factor (scatter plots associated with the green panel). Given the association of these genes to plasma LDL-cholesterol levels, we examined whether rs599839 was associated with LDL cholesterol in a previously published GWAS [35] and found this SNP was significantly associated with LDL cholesterol levels, where the CAD risk allele was associated with higher LDL cholesterol levels in this cohort. Lower levels of CELSR2 and SORT1 expression were associated with the risk allele in humans, and with higher LDL cholesterol levels in mouse, making them ideal candidate susceptibility genes for the CAD and LDL cholesterol associations to this locus. On the other hand, lower levels of PSRC1 expression were associated with the risk allele in humans, but with lower LDL cholesterol levels in mouse, suggesting that PSRC1 is not the gene increasing CAD risk, but instead may be acting to protect against it.