Figure 1. Enzyme defects related to aldosterone synthesis. Schematic of adrenal steroidogenesis demonstrating the various enzymes involved in aldosterone synthesis (large black box). The red lines indicate the specific enzymatic defects that result in defects in aldosterone synthesis. Cortisol circulates in the bloodstream at higher concentrations than aldosterone and it also interacts with MR. However, within the kidney and target tissues, there is selectivity of MR by aldosterone due to the enzyme 11βHSD2 that converts active cortisol to inactive cortisone (small black box). SCC: side-chain cleavage. HSD: hydroxysteroid dehydrogenase. MR: mineralocorticoid receptor. DHEA: dehydroepiandrosterone. Aldo: aldosterone.