Transient Neonatal Zinc Deficiency Caused by a Novel Mutation in the SLC30A2 Gene

This is a case report of a 4‐month‐old full‐term, fully breastfed boy who presented with a persistent periorificial and groin rash associated with poor weight gain and irritability. His serum zinc level was low. The mother's breast milk zinc level was found to be low despite her serum zinc levels being normal, confirming the diagnosis of transient neonatal zinc deficiency. Mutational analysis revealed a novel mutation in the mother's SLC30A2 gene, which encodes a zinc transporter expressed in mammary gland epithelial cells.