THE S-A GENE - PREDISPOSITION TO HYPERTENSION AND RENAL-FUNCTION IN MAN

1. The S-A gene is expressed in the kidneys and is associated with hypertension in man and experimental animal models, Predisposition to hypertension is associated with renal haemodynamic abnormalities and increased renal S-A gene expression. 2. We studied the distribution of the S-A gene alleles (A1, A2), defined by the PstI polymorphism, in young adults with contrasting predisposition to hypertension to determine whether genetic variation at the S-A gene locus is associated with variations in renal haemodynamics, electrolyte metabolism and the renin-angiotensin system. 3. The frequency of the A2 allele was not significantly different between subjects with high personal and parental blood pressures and subjects with low personal and parental blood pressures, We detected no overall relationship between blood pressures and S-A genotype, even after taking sodium intake into account. 4. Glomerular filtration rate, renal blood flow, renal vascular resistance, plasma volume, exchangeable sodium and total body water did not differ according to S-A genotypes, Moreover, we detected no significant effect of S-A genotype on circulating components of the renin-angiotensin system or atrial natriuretic peptide. 5. In our population, genetic variation at the S-A gene locus defined by PstI polymorphism does not influence the renal characteristics that contribute to the development of hypertension.