ANGIOTENSINOGEN GENE AND HYPERTENSION IN CHINESE

The renin-angiotensin system plays a major role in regulating blood pr essure and maintaining electrolyte and volume homeostasis, Previously, the angiotensinogen gene, which encodes the key substrate for renin w ithin this system, has been reported linked to and associated with ess ential hypertension in White Europeans, African-Caribbeans, and Japane se, Therefore, we investigated whether the angiotensinogen gene might be similarly implicated in the pathogenesis of essential hypertension in Chinese by carrying out linkage analysis in 310 hypertensive siblin g pairs, Genotypes for two diallelic DNA polymorphisms observed at ami no acid residues 174 (T174M) and 235 (M235T) within the coding sequenc e and for two highly informative dinucleotide (GT)-repeat sequences (o ne in the 3' flanking region, and one at a distance of 6.1 cM from the gene) were determined, Affected sibpair analysis conducted according to three different algorithms (S.A.G.E./SIBPAL, MAPMAKER/SIBS, and APM methods) revealed no evidence for linkage of the angiotensinogen gene to hypertension. Our data indicate that molecular variants of this ge ne do not appear to contribute materially to the pathogenesis of prima ry hypertension among Chinese (a notion supported by concomitant, dire ct estimates of power), and that the disease relevance of this gene ma y vary therefore depending on ethnicity.