Hypokalemia in pregnancy: Clue to Gitelman syndrome

A normotensive 38-year-old woman had severe hypokalemia and metabolic alkalosis in her 16th week of pregnancy. She also had hypomagnesemia and hypocalciuria and evidence of activation of the renin/aldosterone system. DNA analysis revealed a mutation in the sodium chloride co-transporter gene, NCCT, located in the distal renal tubule. Gitelman syndrome was diagnosed, and she required massive potassium and magnesium supplements during pregnancy. She delivered, uneventfully, a healthy baby girl. We review the molecular pathophysiology of Gitelman syndrome and related tubular disorders and discuss management in pregnancy.