Renin, ANP, ACE polymorphisms, blood pressure and age in American Samoans: Preliminary data

Molecular studies have identified numerous candidate genes that may influence interindividual variation in physiologically important endpoints. Among these are molecular variants of three proteins associated with blood pressure regulation, renin, atrial natriuretic peptide (ANP), and angiotensin-converting enzyme (ACE). These loci are polymorphic in all populations examined. The purpose of this study was to determine gene and genotype frequencies at these three loci in a sample of American Samoans and to examine associations of the various genotypes with blood pressure, hypertension, and age. Genotype frequencies of a BglI restriction fragment length polymorphisms (RFLP) at the renin locus were slightly out of Hardy-Weinberg expectations (P ⩽ 0.025). Frequencies of a BglI RFLP at the ANP locus and of the insertion/deletion polymorphism at the ACE locus approximated Hardy-Weinberg expectations (P ⩾ 0.10). These frequencies differed from those reported in "Afro-Caribbean" and "Caucasian" samples from London. Neither average blood pressures nor the frequencies of either systolic or diastolic hypertension differed significantly across genotypes at the ANP or ACE loci. However, systolic pressure was elevated among those heterozygous for the renin BglI cut site (P = 0.07). Mean age was 34.4 years among individuals heterozygous for the ANP BglI cut site, while it was 46.0 years for homozygotes without the site (P = 0.04). After dividing the sample at its median age (45 years), 31.8% of younger, but only 8.7% of older participants were ANP BglI heterozygotes (G = 9.48; P = 0.005). Am. J. Hum. Biol. 10:439-449, 1998. © 1998 Wiley-Liss, Inc.