The first study reported no effect for a Taq1 restriction fragment length polymorphism on hypertension and blood pressure level.13 Stevens et al.14 and Brown et al.16 studied on single base insertion of adenine at position 138 in the ET-1 gene, and showed the association between the polymorphism and DBP among control subjects with normal blood pressure. This evidence concerns the gene EDN1 and Hypertension.