ESPE Abstracts

Purpose: This study aimed to profile children diagnosed with hypercalcemia of different etiologies at a single center.

Method: We retrospectively reviewed 13 children diagnosed with hypercalcemia of different etiologies.

Results: We describe 13 pediatric cases, aged 4 months to 12 years old (median age: 8 months), diagnosed from 2018 to 2021. Six males and seven females were included, with varied clinical presentations across departments. The most common etiology was malignant tumors (6/13), including one parathyroid carcinoma, one neuroblastoma, three leukemias, and one ovarian malignant tumor. Genetic disorders were the second most common cause (5/13), including glycogen storage disease type I，hypophosphatasia caused by ALPL gene mutation, idiopathic infantile hypercalcemia (IIH) caused by CYP24A1 gene mutation, hypocalciuric hypercalcemia caused by CaSR gene mutation, and infantile hypercalcemia caused by SLC34A1 gene mutation. Except for one child with parathyroid carcinoma, all had high serum calcium levels and normal or lower serum parathyroid hormone (PTH) levels.

Conclusions: Hypercalcemia is a rare condition in childhood. The etiology of hypercalcemia in children can differ by age and include a broad differential diagnosis. All forms of hypercalcemia should be interpreted according to the serum PTH level. The vast majority of hypercalcemia that occurs in childhood is PTH-independent and is attributed to genetic disorders in infants and malignant tumors in older children and adolescents. As untreated hypercalcemia can have a profound impact on a child's growth and development, it is important to have a prompt diagnosis and intervention.