[Asymptomatic hypokalemia and hypomagnesemia with renal cation loss (Gitelman syndrome)]

Hypokalemia with hyperkaliuresis was diagnosed in a 10 1/4-year-old boy, who presented with spontaneously disappearing abdominal pain. The diagnosis of Gitelman-Syndrome (asymptomatic chronic hypokalemia and -magnesemia) was established after detection of hypomagnesemia, renal magnesium losing but normal renin-angiotensin-aldosterone system and glomerular filtration rate. After oral supplementation of potassium hypokalemia persisted and hyperkaliuresis increased. The substitution was discontinued, the hyperkaliuresis diminished and the child remained asymptomatic during a 24 months follow-up. The substitution of potassium and magnesium can be avoided in children with Gitelman-Syndrome as long as they remain asymptomatic.