Association of polymorphisms in the promoter region of the PNMT gene with essential hypertension in African Americans but not in whites

Background: Several studies have indicated that a region on human chromosome 17 may influence blood pressure. Our group reported positive linkage for hypertension to the region on human chromosome 17, between D17S1814 and D17S800 in white sibling pairs. In this study, we further investigated this result by examining the phenylethanolamine N-methyltransferase (PNMT) gene, which is located at 17q21 within the region where we found linkage. Methods: A case/control association study was conducted to evaluate the relationship between genetic variants of the PNMT gene and risk for essential hypertension. Two single nucleotide polymorphisms (SNPs) in the promoter region of the gene were genotyped, PNMT-148 and PNMT-353, in three ethnic samples: African American (117 hypertensive, 96 normotensive), American white (91 hypertensive, 80 normotensive), and Greek white (99 hypertensive, 90 normotensive), using the homogeneous mass extend reaction (Sequenom) and RFLP for genotyping. Results: A significant difference in allelic frequency of SNP-353 between hypertensives (38.02%) and normotensives (27.35%) in African Americans (P = .019) was found; however, no significant differences were observed for this SNP for the other ethnic groups. No association was found with SNP PNMT-148 in any of the ethnic groups. Frequencies of haplotypes based on the two SNPs were also compared between hypertensive and normotensive individuals. No significant difference was found in estimated haplotype frequencies between hypertensive and control subjects in the three ethnic groups. Conclusions: These results suggest that genetic variants of PNMT may play a role in the development of essential hypertension. (C) 2003 American Journal of Hypertension, Ltd.