[Bartter syndrome].

Bartter's syndrome, sometimes a familial autosomal recessive condition, is characterized by hypokalaemia with normal kaliuresis, hyperreninaemia with secondary hyperaldosteronism, vascular resistance to angiotensin and overproduction of prostaglandins by the kidneys. This syndrome is rare but sometimes envisaged in patients with unexplained hypokalaemia, the main difficulty being to exclude intoxication with diuretics which is very similar in all respects. Its physiopathology is unknown, and the various hypotheses put forward since it was first described (vascular insensitiveness to angiotensin, defect of sodium or chloride reabsorption, excess of atrial natriuretic factor, general abnormality of membrane permeability) were unable to demonstrate their primary character, each disorder described seeming, subsequently, secondary to another. For this reason, treatment is difficult and disappointing, but although the hypokalaemia is sometimes worrying, Bartter's syndrome is usually a benign condition.