Types of RTA: Type 2: Proximal RTA

This form of RTA occurs most frequently in children as part of a disorder called Fanconi's syndrome. The symptoms of Fanconi's syndrome include high levels of glucose, amino acids, citrate, and phosphate in the urine, as well as vitamin D deficiency and low blood-potassium.

Proximal RTA can also result from inherited disorders that disrupt the body's normal breakdown and use of nutrients. Examples include the rare disease cystinosis (in which cystine crystals are deposited in bones and other tissues), hereditary fructose intolerance, and Wilson's disease.

Proximal RTA also occurs in patients treated with ifosfamide, a drug used in chemotherapy. A few older drugs--such as acetazolamide or outdated tetracycline--can also cause proximal RTA. In adults, proximal RTA may complicate diseases like multiple myeloma, or it may occur in people who experience chronic rejection of a transplanted kidney.

When possible, identifying and correcting the underlying causes are important steps in treating the acquired forms of proximal RTA. The diagnosis is based on the chemical analysis of blood and urine samples. Children with this disorder would likely receive large doses of oral alkali, such as sodium bicarbonate or potassium citrate, to treat acidosis and prevent bone disorders, kidney stones, and growth failure. Correcting acidosis and low potassium levels restores normal growth patterns, allowing bone to mature while preventing further renal disease. Vitamin D supplements may also be needed to help prevent bone problems.

source: http://kidney.niddk.nih.gov/kudiseases/pubs/tubularacidosis/index.htm