Pseudohypoparathyroidism associated with Gitelman syndrome. Case report

Abstract

Introduction: Pseudohypoparathyroidism (PHP) is a genetic disease with a very low prevalence that causes parathyroid hormone (PTH) resistance, in which patients present complications secondary to the resulting hypocalcemia. Clinical case: A 37-year-old man with a history of tetanic seizures since childhood and an imprecise diagnosis of hypokalemic periodic paralysis since 2013 was admitted to the emergency department of a secondary care hospital in Bogotá D.C., Colombia, due to paresthesia in his hands and feet for two days, which worsened to painful intermittent muscle spasms. The patient stated that he had no genetic family history. Laboratory tests showed hypocalcemia, hypomagnesemia, hyperphosphatasemia, hypokalemia, and elevated PTH levels (369 pg/mL). Therefore, after ruling out several causes of secondary hyperparathyroidism, PTH-dependent hypocalcemia compatible with PHP was suspected. Simultaneously, the patient had compensated metabolic alkalosis, increased renal potassium loss, hypocalciuria, and normal blood pressure, raising the possibility of Gitelman syndrome (GS). Taking this into account, calcium, potassium and magnesium supplementation was started, achieving the complete resolution of the symptoms and normal electrolytes levels. However, it should be noted that since the hospital where the patient was treated did not have the necessary means to perform genetic tests, which is common in Colombia, it was not possible to confirm the diagnosis of both conditions. Conclusion: Although genetic confirmation of the PHP and GS diagnoses was not possible in this case, this would be the second case reported in the world of a patient with clinical suspicion of PHP and GS, which could be a new, yet unknown, genetic mutation that explains the simultaneous occurrence of these two conditions.

Keywords

• Pseudohypoparathyroidism
• Gitelman Syndrome
• Hypocalcemia
• Hypokalemia
• Case report