Somatic mutations in SLC30A1 cause disruptions in cellular zinc homeostasis leading to primary aldosteronism. This is reported by the authors of a study recently published in Nature Genetics. Primary aldosteronism (PA) is a condition in which too much aldosterone is produced, a hormone released by the adrenal glands. PA is the most common cause of secondary hypertension, which refers to high blood pressure that occurs due to endocrine abnormalities independent of the renin-angiotensin system. The disorder is associated with a strongly elevated risk for cardiovascular and renal diseases.

Using exome sequencing, the researchers discovered somatic in-frame deletions in SLC30A1 present in tissue samples of aldosterone-producing adenomas/nodules taken from PA patients. SLC30A1 encodes a zinc transport protein called ZnT1. It belongs to a family of proteins that are essential in regulating cellular zinc homeostasis. Specifically, ZnT1 is responsible for exporting zinc out of cells, thus reducing intracellular zinc concentration. From the results of their functional investigations, the researchers conclude that the identified mutations in SLC30A1 cause an abnormal influx of sodium into cells, leading to depolarization of the resting membrane potential and increase in cytosolic calcium activity, ultimately resulting in excessive production of aldosterone hormone.