NPPA and left ventricular hypertrophy: Previous studies have shown an association of a single nucleotide polymorphism rs5068 in the NPPA locus gene with higher levels of circulating atrial natriuretic peptide as well as with lower intra individual blood pressure, but up to date, no association between rs5068 and cardiac organ damage, i.e. left ventricular hypertrophy, has been accounted for in humans.