Successful treatment of hypercalcemia in a Chinese patient with a novel homozygous mutation in the CYP24A1 gene using zoledronic acid: a case report.

OBJECTIVES: To emphasize the significance of genetic mutations in idiopathic infantile hypercalcemia and the potential therapeutic effectiveness of zoledronic acid in managing hypercalcemia attributed to gene mutations. CASE PRESENTATION: A 1-year-old female infant was referred to our hospital. The patient developed hypercalcemia despite no vitamin D prophylaxis or intake. In the acute phase, conventional calcium-lowering treatments showed limited efficacy, while the administration of zoledronic acid demonstrated effectiveness in controlling hypercalcemia. Subsequently the patient maintained normal calcium levels via a low-calcium diet and avoiding vitamin D intake. Genetic testing confirmed a homozygous mutation (c.476G>C) in the CYP24A1 gene. CONCLUSIONS: Family screening and genetic counseling are crucial for early detection and prevention of hypercalcemia. This case emphasizes the importance of genetic mutations in disease development and the potential therapeutic efficacy of zoledronic acid in managing hypercalcemia attributed to gene mutations.