EP1869 - LBA_ECE_1302 - A case report of a 17 year old male patient presenting with tetany and secondary hyperparathyroidism. A diagnostic revision
Year: 2026
Type: article
Study design: Case Report
Abstract: Background Pseudohypoparathyroidism (PHP) is a group of heterogeneous genetic disorders, characterized by kidney and bone unresponsiveness to PTH, with hypocalcemia, hyperphospatemia and elevated parathormone levels. It is divided into PHP Type 1 and 2. Type 1 demonstrates diminished cAMP and phosphate excretion in urine and Type 2 shows normal cAMP response but blunted phosphate excretion. PHP type 1b is defined as resistance to PTH in the kidney and normal PTH response in bone. Unlike patients with PHP type 1a and 1c patients with type 1b do not have phenotypic expression of Albright hereditary osteodystrophy (AHO). The differential diagnosis of hypocalcemia includes hypoparathyroidism, Vitamin D deficiency and chronic kidney disease. Clinical Case A 17-year-old boy presented with tetany. He had no notable prior personal of family medical history, skeletal abnormalities or intellectual impairment. During physical examination Chvostek sign was positive and intermittent carpometacarpal spasms were present. Biochemical testing revealed Calcium: 5.7 mg/dl, PTH: 188 pg/mL (12-65), 25(OH)VitD:35 ng/mL. Imaging studies were normal. He received intravenous calcium and alfacalcidol when normocalcemia was achieved, he was switched to oral treatment with calcium carbonate, alfacalcidol and cholecalciferol. In his first follow up visit,patient demonstrated normal calcium levels, hyperphosphatemia, normal creatinine,high parathormone and suboptimal 25(OH)D3(19.7 ng/mL) levels. Due to limited resources, genetic testing was not performed and the patient was treated as a suspected case of pseudohypoparathyroidism type 1. During his follow up visits, primary hypothyroidism was diagnosed and he achieved adequate 25(OH)VitD3 levels (>30 ng/mL) for a limited period. On his last visit at the pediatric department, his lab exams showed normal calcium, parathormone and 25(OH)VitD3 levels. In view of these results, the initial diagnosis was re-considered.The patient discontinued treatment for one month, after which a repeat biochemical workup was performed revealing normal calcium,phosphorus, parathormone, suboptimal 25(OH)VitD3 and normal 1,25(OH)2VitD3 levels (Ca: 9.9 mg/dl, P: 4.5 mg/dl Creat: 1 mg/dl, Alb: 4.2 g/dl, PTH: 44 pg/mL, 25(OH)VitD3: 17 ng/mL, Mg: 2 mg/dl, 1,25Vit(OH)D3 46 pg/mL). The results were evaluated, revising the diagnosis to secondary hyperparathyroidism due to Vitamin D deficiency. The patient will receive cholecalciferol monotherapy until his next follow-up appointment. Conclusion This case illustrates the diagnostic challenges of calcium disorders, as the initial diagnosis of pseudoparathyroidism, was re-evaluated during follow-up and the patient was managed as a case of severe and prolonged Vitamin D deficiency and secondary hyperparathyroidism.
Language: English
Subfield: Nephrology
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $4,292
OpenAlex ID: W7213368366