Study of Genetic Variation of the gene NOS3 and Cadmium Concentrations in a Sample of Iraqi Patients with Essential Hypertension

Abstract

High blood pressure is defined as a systolic blood pressure of 140 mm Hg or more, or a diastolic blood pressure of 90 mm Hg or more. Blood pressure is the force exerted by the circulation of blood on the walls of the body’s arteries, which are the main blood vessels in the body. High blood pressure is classified into normal, first stage, second stage, or third stage. Risk factors include lifestyle factors, environmental factors, and genetics. There are two types of high blood pressure, essential hypertension and non-essential hypertension. samples were collected, representing 50 samples from welding laborers patients with high blood pressure, in addition to 50 healthy samples. This study was conducted with the aim of studying the relationship between genetic variation of some genes and environmental factors associated with basic blood pressure in Iraqi patients. The studies were conducted in the laboratories of the Institute of Genetic Engineering - University of Baghdad, as well as in the research laboratories of the Ministry of Science and Technology. Total genomic DNA was extracted using a special kit (Geneaid) from fresh unfrozen blood samples, and then normal polymerase chain reaction and PCR-RFLP were used to detect mutations in the gene NOS3 rs1799983 T>G (Glu 298 Asp) using primers and specialized severing enzyme is MboI. The results of the wild-type TT of NOS3 gene showed a bundle (206 bp), while the heterozygous TG genotypes showed (206, 119 and 87 bp), respectively, and for the mutant GG genotypes (119 and 87 bp). Nitrogenous base sequence analysis (Sequencing) was conducted for both infected and healthy samples. The results of the study showed that the incidence of hypertension in the age group (20-65) years was higher in males than in females, reaching (60% and 40%), respectively. The study showed that stress, smoking and exposure to pollution all have a clear and dangerous effect on the percentage of people with high blood pressure. The results also showed that mutations between patients and healthy subjects in the NOS3 gene for wild-type TT is (60%) versus (40%), respectively, at a significant level (p<0.01), while for the heterozygous TG it is (28)% versus (32%) found not significant. As for the GG homozygous mutant, the results were (12%) versus (28%) found to be significant at (p<0.05) and these results indicate that genetic variation (T>G) may be a risk factor (TT) for high blood pressure. The results of the NOS3 gene also showed the relationship between the TT genotype of the NOS3 gene and the cadmium concentration between patients and healthy subjects for the wild-type TT is 4.82 ± 0.09 versus 0.388 ± 0.025 with a level (p<0.01) while for the heterozygous TG is 4.96 ± 0.10 versus 0.371 ± 0.035 with a level (p<0.01). The homozygous mutant GG is 5.02 ± 0.08 versus 0.356 ± 0.025 with a level (p<0.01). These results indicate that the high level of cadmium in welding laborers has an effect on high blood pressure.