Here is the abstract for the paper I will be presenting at the Human Biology Meetings in Minneapolis.
Intima-media thickness (IMT) of the common and internal carotid arteries is a well known marker of subclinical atherosclerosis and a strong predictor of heart disease and stroke. IMT differs between ethnic populations and higher incidences of stroke have been demonstrated in Hispanics. The objective of this study was to conduct genome-wide association (GWA) and biological pathway analysis of IMT measurements in Mexican American participants from the San Antonio Family Heart study (SAFHS). B-mode carotid ultrasound was performed among 772 SAFHS participants and the near and far wall of the common and internal carotid artery were measured. GWA (based on Illumina’s HumanHap 550K BeadChip) was performed under an additive measured genotype association model, accounting for the non-independence of family members with a random effects kinship model. Models were corrected for age, sex, systolic blood pressure, BMI, diabetes, diabetes medication, and lipids. No significant associations were detected after correcting for multiple-testing (p=5.0x10-8). The strongest suggestive association was observed on chromosome 15q24 at rs4886741 for carotid artery far wall IMT (P=3.6x10-7) within an intergenic region. Nominally significant SNPs (p<0.01) were then entered into Ariadne Pathways Studio to identify relevant biological pathways and to investigate how the assignment of intergenic SNPs to genes might impact these results. The WNT-signaling (p=7.8x10-5) pathway remained significant for both the internal and common carotid arteries under a variety of analysis scenarios. We conclude that through investigation of nominally significant SNPs we are able to detect biological pathways influencing IMT in SAFHS participants.
