A type of renal tubular acidosis characterized by a failure of the proximal tubular cells to reabsorb bicarbonate, leading to urinary bicarbonate wasting and subsequent acidemia.

Pseudohypoaldosteronism type II (PHAII) is characterized by hyperkalemia despite normal glomerular filtration rate (GFR) and frequently by hypertension. Other associated findings in both children and adults include hyperchloremia, metabolic acidosis, and suppressed plasma renin levels. Aldosterone levels are variable, but are relatively low given the degree of hyperkalemia (elevated serum potassium is a potent stimulus for aldosterone secretion). Hypercalciuria is well described.

Proximal renal tubular acidosis-ocular anomaly syndrome (PRTAO) is a rare autosomal recessive systemic disease resulting from isolated impairment of bicarbonate (HCO3-) reabsorption in the proximal renal tubules, which is characterized by a decreased renal HCO3- threshold. Affected individuals exhibit stunted growth and eye anomalies, including band keratopathy, cataracts, and glaucoma. Affected individuals may also exhibit impaired intellectual development and dental defects (Igarashi et al., 2001; Inatomi et al., 2004; Dinour et al., 2004).