Work

A Hypercalcemic Deception: Uncovering an Unusual Case of Familial Hypocalciuric Hypercalcemia

Year: 2025

Type: article

Abstract: Although a rare cause of hypercalcemia, familial hypocalciuric hypercalcemia (FHH) is an inherited condition most often due to a missense mutation in the calcium-sensing receptor (CASR) gene, giving rise to increased calcium levels with elevated parathyroid hormone (PTH) levels and hypocalciuria. Many clinical features of FHH show a high degree of overlap with the much more common disorder of primary hyperparathyroidism (PHPT), making the correct diagnosis a challenge since surgery should be avoided in FHH. In the current case, although PHPT was initially suspected based on urine biochemistry and imaging, FHH-1 and metastatic micropapillary thyroid cancer were diagnosed following thyroid surgery. Moreover, an underlying novel missense CASR mutation shared with the patient's biological father was uncovered. This case highlights the challenge of making the correct hypercalcemic diagnosis without genetic tools. The concurrence with thyroid cancer has been reported once before, albeit not with this novel CASR mutation.

Source: Cureus

DOI: 10.7759/cureus.95514

Authors: Shruti M Gandhi, Eric S Nylen

Institutions: United States Department of Veterans Affairs, Veterans Health Administration, Washington DC VA Medical Center, George Washington University

Language: English

Topic: Parathyroid Disorders and Treatments

Subfield: Nephrology

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: diamond

OpenAlex ID: W4416815645