From Proteopediaproteopedia link
Carbonic anhydrase inhibitors. Sulfonamide diuretics revisited old leads for new applications
[CAH2_HUMAN] Defects in CA2 are the cause of osteopetrosis autosomal recessive type 3 (OPTB3) [MIM:259730]; also known as osteopetrosis with renal tubular acidosis, carbonic anhydrase II deficiency syndrome, Guibaud-Vainsel syndrome or marble brain disease. Osteopetrosis is a rare genetic disease characterized by abnormally dense bone, due to defective resorption of immature bone. The disorder occurs in two forms: a severe autosomal recessive form occurring in utero, infancy, or childhood, and a benign autosomal dominant form occurring in adolescence or adulthood. Autosomal recessive osteopetrosis is usually associated with normal or elevated amount of non-functional osteoclasts. OPTB3 is associated with renal tubular acidosis, cerebral calcification (marble brain disease) and in some cases with mental retardation.    
[CAH2_HUMAN] Essential for bone resorption and osteoclast differentiation (By similarity). Reversible hydration of carbon dioxide. Can hydrate cyanamide to urea. Involved in the regulation of fluid secretion into the anterior chamber of the eye. 
Publication Abstract from PubMed
Diuretics such as hydrochlorothiazide, hydroflumethiazide, quinethazone, metolazone, chlorthalidone, indapamide, furosemide, and bumetanide containing primary sulfamoyl moieties were reevaluated as inhibitors of 12 human carbonic anhydrases (hCAs, EC 188.8.131.52). These drugs considerably inhibit (low nanomolar range) some CA isozymes involved in critical physiologic processes, among the 16 present in vertebrates, for example, metolazone against CA VII, XII, and XIII, chlorthalidone against CA VB, VII, IX, XII, and XIII, indapamide against CA VII, IX, XII, and XIII, furosemide against CA I, II, and XIV, and bumetanide against CA IX and XII. The X-ray crystal structure of the hCA II-indapamide adduct was also resolved at high resolution.
Carbonic anhydrase inhibitors. Interaction of indapamide and related diuretics with 12 mammalian isozymes and X-ray crystallographic studies for the indapamide-isozyme II adduct.,Temperini C, Cecchi A, Scozzafava A, Supuran CT Bioorg Med Chem Lett. 2008 Apr 15;18(8):2567-73. Epub 2008 Mar 20. PMID:18374572
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.