One is due to mutation in the SLC39A4 gene, which codes for zinc transporter ZIP4 in the affected individual and leads to impairment in the absorption of zinc from the gastrointestinal tract and hence low serum levels of the Zn (<50 mcg/dL); this is referred to as acrodermatitis enteropathica (AE) [7,10]. This evidence concerns the gene SLC39A4 and acrodermatitis enteropathica.