WNK4

The WNK4 gene provides instructions for making a protein that plays a role in blood pressure regulation by helping control the amount of sodium and potassium in the body. The WNK4 protein acts as a kinase, which is an enzyme that changes the activity of other proteins by adding a cluster of oxygen and phosphorus atoms (a phosphate group) at specific positions.

The WNK4 protein regulates channels in the cell membrane that control the transport of sodium or potassium into and out of cells, which occurs primarily in the kidneys. Sodium channels help transport sodium into specialized cells of the kidney, from which it is transferred to the blood. This transfer helps keep sodium in the body through a process called reabsorption. Potassium channels handle excess potassium that has been transferred from the blood into the kidney cells. The channels transport the potassium out of the cells in a process called secretion, so that it can be removed from the body in the urine. The WNK4 protein blocks (inhibits) sodium reabsorption and potassium secretion.

pseudohypoaldosteronism type 2 - caused by mutations in the WNK4 gene

Mutations in the WNK4 gene can cause pseudohypoaldosteronism type 2 (PHA2), a condition characterized by high blood pressure (hypertension) and high levels of potassium in the blood (hyperkalemia). The mutations involved in this condition change single protein building blocks (amino acids) in the WNK4 protein, which leads to an abnormal protein that no longer inhibits sodium channels but inhibits potassium channels more strongly. These mutations cause increased sodium reabsorption and decreased potassium secretion, resulting in hypertension and hyperkalemia.

other disorders - increased risk from variations of the WNK4 gene

Studies have associated normal variations in the WNK4 gene with an increased risk of high blood pressure (hypertension) in people without pseudohypoaldosteronism type 2. A combination of genetic variations and environmental factors likely influence the development of this complex condition.