Gitelman Syndrome: Differential Diagnosis of a Female Young Adult with Generalized Weakness, Hypokalemia, Hypomagnesemia, Inappropriate Kaliuresis and Steps towards Final Clinical Diagnosis

This chapter presents the differential diagnosis of the case of a 23-year-old female patient referred to the emergency department due to persistent generalized muscle weakness, hypokalemia, hypomagnesemia and metabolic alkalosis gradually deteriorating during the last three months as well as the steps towards final clinical diagnosis of the syndrome (Gitelman syndrome).

The patient’s medical history as well as family history were thoroughly reviewed by experienced specialized internists. Detailed physical examination was subsequently performed and a panel of blood biochemistry was ordered accordingly. Differential diagnosis was performed subsequently.

The patient’s medical history was unremarkable. Physical examination of the patient did not reveal any abnormal signs. twice daily blood pressure measurements were within the normal range. Blood tests biochemistry revealed metabolic alkalosis, hypokalemia, hypomagnesemia, hypocalciuria, increased plasma renin activity, and elevated plasma levels of aldosterone. A Gitelman syndrome-like phenotype, including hypomagnesemia and hypocalciuria, has also been associated with mutations in the CLCNKB gene encoding the chloride channel ClC-Kb, the cause of classic Bartter syndrome. The woman was treated with spironolactone and oral potassium supplements, and, once her symptoms disappeared and her serum potassium levels returned to normal, Gitelman's syndrome was officially diagnosed. Gitelman syndrome is typically characterized by hypokalemia, metabolic alkalosis, hypomagnesemia, hypocalciuria, increased serum renin and aldosterone levels and normal arterial blood pressure.