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Measurement of absolute copy number variation reveals association with essential hypertension

Francine Z Marques1, Priscilla R Prestes1, Leonardo B Pinheiro2, Katrina Scurrah3, Kerry R Emslie2, Maciej Tomaszewski4, Stephen B Harrap3 and Fadi J Charchar1*

Author Affiliations

1 Faculty of Science, Federation University Australia, Y Building, University Drive, Mt Helen, 3350, Ballarat, VIC, Australia

2 National Measurement Institute, Sydney, NSW, Australia

3 Department of Physiology, University of Melbourne, Melbourne, VIC, Australia

4 Department of Cardiovascular Science, University of Leicester, Leicester, UK

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BMC Medical Genomics 2014, 7:44  doi:10.1186/1755-8794-7-44

Published: 15 July 2014



The role of copy number variation (CNV) has been poorly explored in essential hypertension in part due to technical difficulties in accurately assessing absolute numbers of DNA copies. Droplet digital PCR (ddPCR) provides a powerful new approach to CNV quantitation. The aim of our study was to investigate whether CNVs located in regions previously associated with blood pressure (BP) variation in genome-wide association studies (GWAS) were associated with essential hypertension by the use of ddPCR.


Using a “power of extreme” approach, we quantified nucleic acids using ddPCR in white subjects from the Victorian Family Heart Study with extremely high (n = 96) and low (n = 92) SBP, providing power equivalent to 1714 subjects selected at random.


A deletion of the CNVs esv27061 and esv2757747 on chromosome 1p13.2 was significantly more prevalent in extreme high BP subjects after adjustment for age, body mass index and sex (12.6% vs. 2.2%; P = 0.013).


Our data suggests that CNVs within regions identified in previous GWAS may play a role in human essential hypertension.

Copy number variation; Blood pressure; Hypertension; Extreme phenotypes; Droplet digital PCR