Hypercalcemia in an Infant with Primary Hyperoxaluria Type 2: A Novel Association

Hypercalcemia in infants presents with a variety of clinical features and the etiology of hypercalcemia varies with age. Here we present a case of hypercalcemia in an infant presenting with nephrocalcinosis and nephrolithiasis. Our investigations led us to a diagnosis of primary hyperoxaluria (PH) type 2, a rare metabolic disorder, along with hypercalcemia, a never before reported association. A 9-month-old female presented with urinary tract infection and systemic features requiring hospitalization and parenteral antibiotics. Investigations revealed bilateral medullary nephrocalcinosis. Genetic testing revealed a diagnosis of Primary hyperoxaluria type 2 with two possible mutations. Sanger sequencing of the parents identified the pathogenic mutation in the mother. This is the first report of a genetically proven case of primary hyperoxaluria type 2 associated with hypercalcemia.