Genomics Inform.  2013 Sep;11(3):129-134. 10.5808/GI.2013.11.3.129.

Genome-Wide Association Study of Orthostatic Hypotension and Supine-Standing Blood Pressure Changes in Two Korean Populations

• Hong KW
• Kim SS
• Kim Y

• KMID: 2009105
• DOI: http://doi.org/10.5808/GI.2013.11.3.129

Abstract

Orthostatic hypotension (OH) is defined by a 20-mm Hg difference of systolic blood pressure (dtSBP) and/or a 10-mm Hg difference of diastolic blood pressure (dtDBP) between supine and standing, and OH is associated with a failure of the cardiovascular reflex to maintain blood pressure on standing from a supine position. To understand the underlying genetic factors for OH traits (OH, dtSBP, and dtDBP), genome-wide association studies (GWASs) using 333,651 single nucleotide polymorphisms (SNPs) were conducted separately for two population-based cohorts, Ansung (n = 3,173) and Ansan (n = 3,255). We identified 8 SNPs (5 SNPs for dtSBP and 3 SNPs for dtDBP) that were repeatedly associated in both the Ansung and Ansan cohorts and had p-values of <1 x 10(-5) in the meta-analysis. Unfortunately, the SNPs of the OH case control GWAS did not pass our p-value criteria. Four of 8 SNPs were located in the intergenic region of chromosome 2, and the nearest gene (CTNNA2) was located at 1 Mb of distance. CTNNA2 is a linker between cadherin adhesion receptors and the actin cytoskeleton and is essential for stabilizing dendritic spines in rodent hippocampal neurons. Although there is no report about the function in blood pressure regulation, hippocampal neurons interact primarily with the autonomic nervous system and might be related to OH. The remaining SNPs, rs7098785 of dtSBP trait and rs6892553, rs16887217, and rs4959677 of dtDBP trait were located in the PIK3AP1 intron, ACTBL2-3' flanking, STAR intron, and intergenic region, respectively, but there was no clear functional link to blood pressure regulation.

Keyword

genome-wide association study; human CTNNA2 protein; orthostatic hypotension; single nucleotide polymorphism

MeSH Terms

Actin Cytoskeleton
Autonomic Nervous System
Blood Pressure
Case-Control Studies
Chromosomes, Human, Pair 2
Cohort Studies
Dendritic Spines
DNA, Intergenic
Genome-Wide Association Study
Hypotension, Orthostatic
Introns
Neurons
Polymorphism, Single Nucleotide
Reflex
Rodentia
Supine Position
DNA, Intergenic