The study was renewed again in FY 2005 to : supplement evidence of hypertension causation on chromosomes 6,7, and 11 with a new set of dense markers and to search for positional candidate genes for hypertension at the two best regions; identify the genes under the linkage peak(s), find appropriate single nucleotide polymorphisms for a frequency of greater than 10% and conduct association/linkage disequilibrium mapping; replicate these findings in additional case-control studies and assess potential gene-environment interactions.