ARG1 Gene Polymorphisms and Their Association in Individuals with Essential Hypertension: A Case-Control Study.

The purpose of this study is to investigate the association of variant alleles (rs2781666 and rs2781667) at ARG1 to be involved in the generation of essential hypertension (EH) phenotypes in human subjects. The ARG1 noncoding polymorphisms (rs2781666; Chr6:131572419-G/T and rs2781667; Chr6:131573754-C/T) were investigated in 570 subjects, including 285 individuals diagnosed with EH. Determination of serum arginase activity and concentrations of nitric oxide catabolites were detected by the colorimetric enzymatic assay. Genetic typing of the noncoding polymorphisms, in ARG1, was performed using PCR and restriction digestion strategy. A significant increase in arginase activity was observed in individuals exhibiting EH phenotypes, compared with controls (p < 0.0001). Arginase showed negative correlation with serum nitrite and nitrate (r = -0.446 and r = -0.6075, respectively). A significant difference to be claimed in the distribution of SNPotypes, in rs2781666 and rs2781667, between cases and controls (p = 0.0086 and p = 0.0232; respectively). Interestingly, variant allele T, at both loci, is tightly linked to the disease phenotypes compared to the wild-type allele (p = 0.002; and p = 0.007, respectively). To our knowledge, this report is the first ever that described arginase activity, and the ARG1 polymorphism data of individuals originated in Pakistan, segregating EH phenotypes, thus, highlighting a novel risk factor for the disease.