A suspicious hypokalemia
A 13 year-old boy was evaluated at our outpatient clinic for short stature. Growth hormone (GH) deficit was diagnosed after stimulation tests with arginine and insulin, and GH therapy was initiated. A few weeks after therapy initiation Blood tests documented hypokalemia (2.7 mmol/L), hypomagnesemia (1,5 mg/dl), and hypochloremia (94 mmol/L). The symptoms and laboratory results seemed not related to the recent initiation of GH therapy, and more suggestive of Gitelman syndrome, which is characterized by potassium and magnesium renal loss and metabolic alkalosis. Short stature and GH deficit are among the most frequent extra-renal symptoms.