Abstract
Acquired zinc deficiency is rare, particularly in breastfed infants. We present a case of a second-born breastfed infant presenting with zinc deficiency whose mother was found to have a novel heterozygous mutation in SLC30A2 . A previous baby did not have manifestations of zinc deficiency but the mother had taken a proton pump inhibitor (PPI) during the second pregnancy. Though little is known regarding the effect of PPI on transplacental or transmammary zinc transmission, antenatal PPI exposure is a plausible contributor to transient infantile zinc deficiency.