title: Measurement of absolute copy number variation reveals association with essential hypertension.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  Our data suggests that CNVs within regions identified in previous GWAS may play a role in human essential hypertension.
authors.forename: Francine Z
authors.initials: FZ
authors.lastname: Marques
authors.forename: Priscilla R
authors.initials: PR
authors.lastname: Prestes
authors.forename: Leonardo B
authors.initials: LB
authors.lastname: Pinheiro
authors.forename: Katrina
authors.initials: K
authors.lastname: Scurrah
authors.forename: Kerry R
authors.initials: KR
authors.lastname: Emslie
authors.forename: Maciej
authors.initials: M
authors.lastname: Tomaszewski
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Harrap
authors.affiliation: Faculty of Science, Federation University Australia, Y Building, University Drive, Mt Helen, 3350, Ballarat, VIC, Australia. f.charchar@federation.edu.au.
authors.forename: Fadi J
authors.initials: FJ
authors.lastname: Charchar
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000235:genetics; D056915:DNA Copy Number Variations; D000075222:Essential Hypertension; D005260:Female; D055106:Genome-Wide Association Study; D005838:Genotype; D006801:Humans; D006973:Hypertension / Q000235:genetics* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction