Disorders of water metabolism are common among the elderly, the acutely and chronically ill, and among patients taking certain medications. Abnormal water balance is detected clinically by an increase or decrease in the serum sodium concentration (hyper- and hyponatremia, respectively). Hyponatremia is the most common of the electrolyte abnormalities and even a modest reduction in serum sodium concentration (i.e., water excess) is associated with substantial morbidity and mortality. Rare mutations in water-regulatory genes cause familial abnormalities of water balance;however, these account for only a small minority of cases of hyponatremia. Our preliminary data strongly support the heritability of systemic water balance;in addition, we have identified a non-synonymous polymorphism in a water-regulatory gene that is associated with hyponatremia in several human populations. No prior studies have addressed the genetics of water balance on a population-wide basis and there is at present no way to predict who is at greatest risk from medications or disease states statistically associated with the development of hyponatremia. The over-arching objective of this proposal is to define the genetics of systemic water balance on a population-wide basis using data derived from prior large-scale NHLBI-sponsored (and other NIH-sponsored) cohort and family-based studies.
In Aim I, we will quantify the heritability of water balance in additional human populations using data from family-based components of large NHLBI-funded cohort studies.
In Aim II, we will identify human genetic polymorphisms associated with aberrant water balance via a candidate gene approach. Banked genomic DNA previously obtained in the course of large NHLBI-funded cohort studies will be used.
In Aim III, genome-wide association studies will be performed to identify in an unbiased fashion genetic polymorphisms associated with aberrant systemic water balance in large cohorts. For this Aim, we will use high-density genotyping data generated as part of ongoing analysis in several NHLBI-funded cohort studies. Through this combination of approaches made possible by NHLBI-supported data generation, we hope to elucidate the human genetic basis for systemic water balance and identify polymorphisms associated with hypo- and hypernatremia.

Public Health Relevance

Disorders of water metabolism cause substantial morbidity and mortality among the elderly, the acutely and chronically ill, and among patients taking certain commonly- prescribed medications. Our preliminary data indicate that heredity determines, in large part, which patients are most susceptible to this complication. We will use an array of data generated in the course of multiple large NHLBI-funded cohort studies to elucidate the human genetic basis for abnormalities in systemic water balance.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK084004-04
Application #
8466312
Study Section
Special Emphasis Panel (ZDK1-GRB-S (J2))
Program Officer
Rasooly, Rebekah S
Project Start
2010-07-01
Project End
2014-04-30
Budget Start
2013-05-01
Budget End
2014-04-30
Support Year
4
Fiscal Year
2013
Total Cost
$340,592
Indirect Cost
$119,428
Name
Oregon Health and Science University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
096997515
City
Portland
State
OR
Country
United States
Zip Code
97239
Fu, Y; Rope, R; Fargue, S et al. (2015) A mutation creating an out-of-frame alternative translation initiation site in the GRHPR 5'UTR causing primary hyperoxaluria type II. Clin Genet 88:494-8
Cohen, David M; Ellison, David H (2015) Evaluating hyponatremia. JAMA 313:1260-1
Kerns, Eric; Patel, Shweta; Cohen, David M (2014) Hourly oral sodium chloride for the rapid and predictable treatment of hyponatremia. Clin Nephrol 82:397-401
Zhang, Zheng; Duckart, Jonathan; Slatore, Christopher G et al. (2014) Individuality of the plasma sodium concentration. Am J Physiol Renal Physiol 306:F1534-43
Baru, Ashvin; Kerns, Eric Scott; Cohen, David M (2013) A reversible cause of 'end-stage renal disease': discrepant findings in serial duplex ultrasonograms in a suspected occlusion of a renal arterial bypass graft. BMJ Case Rep 2013:
Zeng, Liling; Bai, Ming; Mittal, Amit K et al. (2013) Candidate tumor suppressor and pVHL partner Jade-1 binds and inhibits AKT in renal cell carcinoma. Cancer Res 73:5371-80
Cohen, David M; Mittalhenkle, Anuja; Scott, David L et al. (2011) African American living-kidney donors should be screened for APOL1 risk alleles. Transplantation 92:722-5
Fu, Yi; Chen, Zhan; Blakemore, Alexandra I F et al. (2010) Absence of AVPR2 copy number variation in eunatremic and dysnatremic subjects in non-Hispanic Caucasian populations. Physiol Genomics 40:121-7
Tian, Wei; Fu, Yi; Garcia-Elias, Anna et al. (2009) A loss-of-function nonsynonymous polymorphism in the osmoregulatory TRPV4 gene is associated with human hyponatremia. Proc Natl Acad Sci U S A 106:14034-9