Clinical feature: 

Definition: Bartter syndromes is a group genetically heterogenous autosomal recessive disorders characterized by hypokalemic salt-losing tubulopathies.

History: 1968 Bartter first described a new syndrome characterized by hyperplasia of the juxtaglomerular complex with hyperaldosteronism and hypokalemic alkalosis. Today we consider these these symptoms as classic Bartter syndrome although some authors maintain that this two cases were in fact Gitelman syndrome.

Pathogenesis: Wastage of salt and water is a result of inactivating mutations in genes that encode membrane transportes of the thick ascending limb of the loop of Henle. The effect of these mutations on salt and water handling is similar to that of loop diuretics such as furosemide.

Clinical picture: All forms of Bartter syndrome are characterized by hypokalemia, metabolic alkalosis, hyperreninemic hyperaldosteronism, normal blood pressure, and hyperkaliuria. Also renal chloride excretion is incresead when related to serum levels.

Diagnostics: 

Differential: A large volume of diluted urine is also common in diabetes insipidus, which can be neurogenic or nephrogeneic. The normal conservation of of sodium, potassium, chloride, and calcium can be useful to distinguish these conditions.  » » » 
   Gitelman syndrome is similar in many aspects except that its molecular defect is located at the distal tubule and the symptoms also inlcude hypocalciuria and hypomagnesemia. The diagnosis is made at a later age when muscular signs and symptoms give the first hint.  » » » 

Literature: 

BARTTER FC et al. (1962) Hyperplasia of the juxtaglomerular complex with hyperaldosteronism and hypokalemic alkalosis. A new syndrome.
Bichet DG et al. (2004) Reabsorption of sodium chloride--lessons from the chloride channels.
Fujiwara TM et al. (2005) Molecular biology of hereditary diabetes insipidus.
Peters M et al. () Hereditary Hypokalemic Salt-losing Tubular Disorders.