Familial hyperaldosteronism type III

Primary aldosteronism is a frequent form of endocrine hypertension comprising both sporadic and familial forms. Three forms of familial hyperaldosteronism have been described to date. In this chapter we discuss the clinical phenotypes and the genetic basis of familial hyperaldosteronism type III. This condition is caused by a mutation in the KCNJ5 gene, encoding the potassium channel GIRK4 ( also called Kir 3.4), that alters the selectivity filter of the ion channel. In the presence of these mutations, aldosterone secretion is increased leading to a particularly severe form of hyperaldosteronism with early-onset hypertension that is usually resistant to pharmacological treatment and requires bilateral adrenalectomy.