Genes, Salt and Blood Pressure

Abstract

Nephrology| August 01 1999 Genes, Salt and Blood Pressure AAP Grand Rounds (1999) 2 (2): 20–21. https://doi.org/10.1542/gr.2-2-20 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Genes, Salt and Blood Pressure. AAP Grand Rounds August 1999; 2 (2): 20–21. https://doi.org/10.1542/gr.2-2-20 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search toolbar search search input Search input auto suggest filter your search All PublicationsAll JournalsAAP Grand RoundsPediatricsHospital PediatricsPediatrics In ReviewNeoReviewsAAP NewsAll AAP Sites Search Advanced Search Topics: blood pressure, dietary sodium chloride, genes Source: Wong ZY, Stebbing M, Ellis JA, Lamantia A, Harrap SB. Genetic linkage of beta and gama subunits of epithelial sodium channel to systolic blood pressure. Lancet. 1999;353:1222–1225. Two hundred and eighty-six Caucasian families from Victoria, Australia, comprised of both parents and two natural children (ages 18–30 including 32 dizygotic twin pairs) were genotyped at chromosome 16p12. Genomic DNA was analyzed for genes on chromosome 16p12 which code for the beta and gamma subunits of two epithelial sodium channels, SCNNIB and SCNNIG respectively. These genes previously have been shown to be linked with sodium dependent forms of low and high blood pressure. Systolic blood pressure is influenced by pulse pressure which, in turn, reflects left-ventricular stroke volume, the compliance of larger arteries, and reflected pulse waves. Additionally, blood pressure control depends on sodium balance, ie, renal sodium regulation, which in turn determines extracellular fluid volume. A significant linkage between systolic blood pressure and the beta and gamma subunits of chromosome 16p12 was found. The difference in systolic blood pressure of 7.1 mm/Hg between siblings identical at these loci was half as large as the difference (14.0 mm/Hg) between non-identical siblings at these loci. No linkage was found between these genes on chromosome 16p12 and diastolic blood pressure or body mass. In short, this study shows a significant genetic linkage between systolic blood pressure and chromosome 16p12, demonstrating that one or more genes in this chromosomal region contributes significantly to individual variation in systolic blood pressure. This study is important because it shows a distinct genetic influence between genes that regulate sodium absorption and systolic blood pressure.1 Liddle’s syndrome, a heritable form of hypertension, has been shown to be caused by a mutation in the beta sub-unit of the epithelial sodium channel.2 Essential hypertension may be associated with an isolated, elevated systolic pressure, elevated diastolic pressure, or a combination of both. The lack of any correlation with diastolic pressure in this study demonstrates the polygenetic nature of blood pressure control. It may be anticipated that other genes will be identified that regulate factors that influence diastolic blood pressure. Perhaps the genetic alterations in this study may explain part of the blood pressure variability seen in those susceptible individuals whose blood pressure is affected by dietary salt. These studies further suggest that we are getting close to being able to identify genetic tests that can identify children at risk for developing hypertension. Hopefully, dietary and/or drug intervention in at-risk children will someday prevent the onset of some forms of essential hypertension. Experimental studies have shown that in genetically transmitted forms of experimental hypertension, the timing of introducing excessive amounts of salt into the diet can influence both the generation and the persistent phase of hypertension.3 The etiology of essential hypertension can no longer be considered hocus-pocus since we can now focus on a locus. We only wish it were as simple as one chromosome and one locus but, as Dr. Gruskin points out, this... You do not currently have access to this content.