Title: The association of adult GWAS-BP variants with blood pressure trajectories in children.

Background: From genomewide association scans of population cohorts 30 genetic loci with modest influences on blood pressure phenotypes have been identified (paper from large GlobelBPgen consortium currently being drafted with planned date for submission May 2010). These GWAS anayses have been done in adults only and whether these variants similarly relate to BP in children is unknown. It is also possible that a focus upon variation in mean blood pressure does not capture the full information of the effects of genetic variants over time. Recent data from observational cohorts and a cardiovascular intervention trial - again in adults only - suggest that visit to visit systolic BP variability, or maximum systolic BP reached may be an important driver to adverse cardiovascular outcomes (see series of papers by Rothwell et al, Lancet and Lancet Neurology March 2010 and ACC). In the case of the outcome trial this is of considerable interest as the BP variability and maximal systolic correlated strongly with CV outcomes and offered superior predictivity of events than the mean BP differences between the two arms of the trial. In addition, observational cohort data suggest that blood pressure burden and trend over time (from early adulthood) may be an important factor in cardiovascular endpoints.