ABCD syndrome, an uncommon cause of hypercalcemia in pediatrics.

ABCD syndrome (ABnormal Calcium, Calcinosis, and Creatinine in Down syndrome) is characterized by an association of hypercalcemia, hypercalciuria, nephrocalcinosis, and impaired kidney function in patients with Down syndrome. Only 7 cases have been published worldwide, although it is believed to be underdiagnosed. This report describes 2 new patients with ABCD syndrome and compares them with the cases reported to date. Although it is a rare cause of pediatric hypercalcemia, it should be considered in children with Down syndrome once other more common etiologies have been ruled out. Once this diagnosis is confirmed, the recommended treatment is to reduce dietary calcium intake and work with an interdisciplinary team to maintain an adequate calorie and protein intake.