The Unique Presentation of a Pediatric Patient with Gitelman's Syndrome (GS)

Background: Gitelman's Syndrome (GS), also referred to as familial hypokalemia-hypomagnesemia, is an autosomal recessive disorder that affects nearly 1 in 40,000 people worldwide. It is characterized in patients as hypokalemia, hypomagnesemia, hypercalciuria, and metabolic alkalosis. The disease results from 1 of nearly 140 different known mutations that can occur in the thiazide sensitive NaCl co-transporter located in the apical membrane of the distal convoluted tubule resulting in effects similar to thiazide diuretics. Most patients are diagnosed in adolescence and frequently present with complaints of tetany, facial paresthesia's, fatigue, and even delayed growth. Low potassium is especially concerning for the cardiovascular health of these patients. A potential complication is the development of ventricular arrhythmias, and even cardiac arrest, originating from prolonged potentials in cardiomyocytes that manifests as a wide QT interval on ECG. Case Presentation: This report outlines a unique presentation of an 8-year-old female with Gitelman's syndrome (GS). This patient experienced polyuria and polydipsia primarily at night as well as severe episodes of vomiting that her guardian later described as self-induced. Genetic testing for Gitelman's syndrome was eventually performed after labs indicated chronic hypokalemia. Interestingly, in contrast to the normal presentation of GS, labs for this patient showed elevated levels of magnesium instead of the usual hypomagnesemia seen in the majority GS patients. She was later found to have an abnormally prolonged QT interval likely resulting from her decreased potassium levels. Treatment for this patient's GS was potassium chloride to maintain potassium homeostasis. The patient of interest has experienced severe physical and sexually abusive relationships from a young age as well as family instability that eventually resulted in her placement into foster care. She was later placed on Guanfacine, Ritalin, and Zoloft for the treatment of her ADD/ADHD and depression symptoms. Conclusion: In this case report, we describe a pediatric patient and how her diagnosis of GS was made more complicated by abnormal lab values and her significant social circumstances.