Apparent mineralocorticoid excess syndrome (AME) is an autosomal recessive disorder that results in low renin hypertension and other characteristic clinical features.
This mechanism is related either to a mutation of the gene, which encodes 11HSD2 (apparent mineralocorticoid excess syndrome and some cases of low renin hypertension) or to an acquired reduction of the activity of the enzyme due to glycyrrhetinic acid, carbenoxolone, and grapefruit juice.
Inhibition by xenobiotics such as liquorice or mutations in the HSD11 B2 gene, as occur in the rare monogenic hypertensive syndrome of apparent mineralocorticoid excess (AME), result in a compromised 11 betaHSD2 enzyme activity, which in turn leads to overstimulation of the MR by cortisol, sodium retention, hypokalaemia, low plasma renin and aldosterone concentrations, and hypertension.
Mutations generating inactive enzymes have been described in the HSD11B2 gene in the congenital syndrome of apparent mineralocorticoid excess (AME)--a low renin form of hypertension.