A British study of over 10,000 European men and women tested the relation between salt consumption, blood pressure and variation in the gene for angiotensinogen production. Angiotensinogen is a compound which is transformed to angiotensin in the body. One effect of angiotensin is to raise blood pressure by constricting arteries. Some variants of the angiotensinogen gene make people naturally susceptible to hypertension.
Salt consumption raised blood pressure, no matter what angiotensinogen gene the participants had.