Type 2 RTA is very rare and most often occurs in patients who have one of the following: Fanconi syndrome Light chain nephropathy due to multiple myeloma Various drug exposures (usually acetazolamide, sulfonamides, ifosfamide, outdated tetracycline, or streptozocin) It sometimes has other etiologies, including vitamin D deficiency, chronic hypocalcemia with secondary hyperparathyroidism, kidney transplantation, heavy metal exposure, and other inherited diseases (eg, fructose intolerance, Wilson disease, oculocerebrorenal syndrome [Lowe syndrome], cystinosis).