Pseudohypoaldosteronism (PHA) is assigned to a heterogeneous group of disorders of electrolyte metabolism which is distinguished by a clear state of renal tubular unresponsiveness or resistance to the action of aldosterone. The condition is described by hyperkalemia, metabolic acidosis and normal glomerular filtration rate (GFR). Several features are observed in this condition such as volume depletion or hypervolemia, renal salt wasting or retention, hypotension or hypertension, and elevate, normal or low levels of rennin and aldosterone.
The molecular basis for patients suffering from PHA-II is connected to mutations in WNK1 or WNK4. WNKs include a family of serine-threonine protein kinases with unusual placement of the catalytic lysine compared to all other protein kinases. The function of WNK1 and WNK4 lies in regulating chloride co-transporters of the distal nephron and further epithelia.