Abstract P111: A Genome-Wide Gene Expression Study of Blood Pressure in Twins

Abstract

Background: Recently, a genome wide gene expression study identified 34 genes that were differentially expressed in relation to blood pressure (BP). However, to what extend these BP related gene expression signatures are driven by genetic factors or environmental factors have not been investigated. Methods: In this study of 383 twins (84 DZ pairs, 105 MZ pairs and 5 singletons; age 32-69; 40% male) recruited from the Finland Twin Cohort Study, genome-wide gene expression data in peripheral leukocytes were obtained using illumine HT12 V4 array. Systolic and diastolic BP related gene expression changes were identified using linear mixed model. Structural equation modeling was used to estimate the genetic and environmental sources of variance of BP related gene expression signatures. Results: Our genome wide gene expression analysis identified 1 gene ( ECT2 , FDR=0.019) with its expression level associated with SBP and 1 gene ( LMNA , FDR=0.004) with its expression level associated with DBP at the cutoff of FDR<0.05. Out of the previously identified SBP (N=21) and DBP related genes (N=20), 5 genes ( CD97, TAGLN2, MYADM, SL31A2 and TIPARP ) for SBP and 5 genes ( CD97, S100A10, MYADM, TIPARP and SLC31A) for DBPcan be replicated in the twin cohort with same directions and p<0.05. Four genes showed association with both SBP and DBP. Structural equation modeling was conducted on the expression levels of the newly identified BP related genes as well as the ones that were previously identified but can been replicated in this study. Out of the 8 genes, genetic factors contributed significantly to the expression of 2 genes ( LMNA and S100A10 ) and shared environmental factors contributed significantly to the expression of 1 gene ( MYADM ), while for 5 genes, both genetic and shared environmental factors have significant contributions to their gene expression levels. Conclusion: In this study of twins, we identified novel genes with its expression level associated with BP and replicated several previously identified signals. Our study further provides new insights into the genetic and environmental sources of BP related gene expression signatures.