Acrodermatitis enteropathica, zinc-deficiency type (AEZ), is a rare autosomal recessive disease caused by severe zinc deficiency. It typically appears in the first few weeks after birth if the child is fed bovine milk or shortly after cessation of breastfeeding. AEZ is characterized by acral dermatitis, alopecia, diarrhea and growth failure. Other features associated with severe and chronic zinc deficiency include failure to thrive, mental slowness, photophobia, hypogeusia, anemia, poor wound healing, hypogonadism in males, and delayed puberty.
Diagnosis of AEZ is based on the symptoms (diarrhea and acral dermatitis) and laboratory testing for plasma zinc concentrations and serum alkaline phosphatase. Affected patients have low levels of zinc and alkaline phosphatase. Also, molecular genetic testing for the SLC39A4 gene mutations could be performed to confirm the diagnosis.There is no cure for the AEZ disease. However, zinc supplementation therapy for lifetime results in the disappearance of the symptoms. Without appropriate zinc supplementation, acrodermatitis enteropathica usually is lethal within the first few years of life.
Mutations in the SLC39A4 gene are the cause of acrodermatitis enteropathica, zinc-deficiency type (AEZ). SLC39A4 gene encodes a zinc transporter protein called the Zip4 transporter, which plays an important role in the transcellular absorption of zinc into the enterocytes of the duodenum and jejunum. Defects in this protein lead to zinc malabsorption, causing the symptoms of AEZ disease.