SPECIFIC AIM 3: To determine effect of heterozygosity for the GHRHR mutation. To this end, we propose to genotype a large number of apparently normal members of the Itabaianinha community with the goal of separating subjects homozygous for the wild-type allele from subjects heterozygous for the GHRHR mutation, and to compare their phenotype with the one observed in subjects homozygous for the wild type allele residing in the same geographical area.