AT1R A1166C gene polymorphism is associated with essential hypertension in Caucasions [23]–[24], [26]–[27], Iranian [28] and Asian populations [29]–[31] while other studies have shown no significant association in Nigerian [32], Kazakans [33], Japanese [34] and South Indian Tamilian population [35]. This evidence concerns the gene AGTR1 and essential hypertension.