Monogenic forms of low-renin hypertension

Seven single gene mutations are known to cause hypertension, generally by affecting electrolyte transport in the distal nephron, or synthesis or activity of mineralocorticoid hormones. These relatively uncommon disorders should be considered when young patients with a family history of high blood pressure present with severe or refractory hypertension. This article guides clinicians through identification of these defects, their associated laboratory findings, and recommended treatments. Hypertension is an important public health problem affecting more than 50 million individuals in the US alone. The most common form, essential hypertension, results from the complex interplay between genetic predisposition and environmental influences. In contrast, monogenic (mendelian) forms of hypertension are caused by single gene mutations that are influenced little, if at all, by environmental factors. Most monogenic forms of hypertension affect either electrolyte transport in the distal nephron, or the synthesis or activity of mineralocorticoid hormones, leading to the common pathogenic mechanisms of increased distal tubular reabsorption of sodium and chloride, volume expansion and hypertension. In young patients with a family history of hypertension who present with severe or refractory hypertension and characteristic hormonal and biochemical abnormalities, the differential diagnosis should include monogenic forms of hypertension. Genetic testing, which is increasingly available, can facilitate timely diagnosis and treatment of these relatively uncommon disorders, such that the underlying defect can be corrected or ameliorated and the long-term consequences of poorly controlled hypertension prevented.