As this phenotype in mice mirrors TNZD (OMIM number 608118) in breast-fed infants [7–9] Michalczyk et al. investigated whether changes in the ZnT4 gene are responsible for reduced Zn2+ in breast milk in human in two unrelated mothers with low Zn2+ milk levels whose babies had developed Zn2+ deficiency. Here, SLC30A4 is linked to zinc deficiency, transient neonatal.