-Case Reports-

A Case of Gitelman Syndrome that Was Difficult to Distinguish from Hypokalemic Periodic Paralysis Caused by Graves' Disease

Takeshi Oba¹, Shunsuke Kobayashi¹, Yuko Nakamura¹, Mototsugu Nagao¹, Kandai Nozu², Izumi Fukuda¹, Kazumoto Iijima² and Hitoshi Sugihara¹

¹Department of Endocrinology, Diabetes and Metabolism, Graduate School of Medicine, Nippon Medical School, Japan
²Department of Pediatrics, Kobe University Graduate School of Medicine, Japan

A 21-year-old man presented with hyperthyroidism and hypokalemia and was treated for thyrotoxic hypokalemic periodic paralysis caused by Graves' disease. Thyroid function soon normalized but hypokalemia persisted. Laboratory data revealed hyperreninemic hyperaldosteronism and metabolic alkalosis consistent with Gitelman Syndrome. The patient was found to have a previously unreported compound heterozygous mutation of T180K and L858H in the SLC12A3 gene, and Gitelman Syndrome was diagnosed. He was started on eplerenone to control serum potassium level. Alternative diagnoses should be considered when electrolyte imbalances persist after disease resolution.

J Nippon Med Sch 2019; 86: 301-306

Keywords
eplerenone, Gitelman syndrome, thyrotoxic hypokalemic periodic paralysis, hypokalemia, SLC12A3 gene

Correspondence to
Izumi Fukuda, MD PhD, Department of Endocrinology, Diabetes and Metabolism, Graduate School of Medicine, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8603, Japan
i-fukuda@nms.ac.jp

Received, December 10, 2018
Accepted, April 17, 2019