Human diseases have been shown to be caused also by variants in ZnT proteins: heterozygous ZnT2 mutations cause transient neonatal zinc deficiency; ZnT8 polymorphism has been associated with augmented risk of type 2 diabetes; and, as we have previously shown,12 biallelic ZnT9 (SLC30A9) mutation causes Birk‐Landau‐Perez cerebro‐renal syndrome (OMIM 604604), characterized by global developmental delay from infancy or early childhood. The gene discussed is SLC30A9; the disease is type 2 diabetes mellitus.