Hypoparathyroidism, Sensorineural Deafness, and Renal Disease Syndrome Presenting With Febrile Seizures and Hypocalcemia

HDR syndrome is a rare genetic disorder caused by mutations in the GATA3 gene and characterized by hypoparathyroidism, sensorineural deafness, and renal disease. Here, we report case of a 9-month-old male with history of hydronephrosis and sensorineural deafness who presented with febrile seizures. He was found to have hypocalcemia and inappropriately normal parathyroid hormone. His neurologic and infectious workup were negative. Genetic testing revealed a nonsense mutation in the GATA3 gene, consistent with HDR syndrome. Hypocalcemia was responsive to calcium carbonate and calcitriol treatment. This case highlights hypocalcemia caused by hypoparathyroidism as a potential etiology of seizures. When hypoparathyroidism is detected with either hearing loss or renal disease, HDR syndrome should be considered, and other features of the syndrome should be investigated.