Bartter's syndrome, chondrocalcinosis and nephrogenic hypomagnesemia in an adult. Bartter's syndrome, chondrocalcinosis and nephrogenic hypomagnesemia in an adult. Bartter's syndrome, initially described in children, becomes a controversial entity when it is observed in adults, as it cannot be dissociated easily from the pseudo Bartter's syndrome caused by an abuse of diuretics or provoked by surreptitious vomiting. Yet its association with chondrocalcinosis, about ten cases of which have already been published and which is not reproducible by prolonged diuretic treatment, seems to give it some authenticity. The link between the two conditions might well be the low blood magnesium level observed significantly in both diseases and constantly when they are associated. This hypomagnesaemia is of renal origin and it may reflect a complex tubular disorder which also includes a defect of chloride reabsorption by the tubule. We report here a case of diffuse chondrocalcinosis and Bartter-like syndrome in a 38-year old woman, leading to the discovery of nephrogenic hypomagnesaemia.