Acrodermatitis enteropathica of the zinc deficiency type (AEZ) is characterized by intermittent simultaneous occurrence of diarrhea and dermatitis with failure to thrive. Alopecia of the scalp, eyebrows, and eyelashes is a usual feature. The skin lesions are bullous. Noteworthy is the cure by diodoquin, or diiodohydroxyquinoline (Dillaha et al., 1953; Bloom and Sobel, 1955). Rodin and Goldman (1969) described autopsy findings, including pancreatic islet hyperplasia, absence of the thymus and of germinal centers, and plasmocytosis of lymph nodes and spleen.

Transient neonatal zinc deficiency occurs in breast-fed infants as a consequence of low milk zinc concentration in their nursing mothers, which cannot be corrected by maternal zinc supplementation. A large amount of zinc, an essential trace mineral, is required for normal growth particularly in infants, and breast milk normally contains adequate zinc to meet the requirement for infants up to 4 to 6 months of age. Zinc deficiency can lead to dermatitis, alopecia, decreased growth, and impaired immune function. The disorder shows autosomal dominant inheritance with incomplete penetrance (summary by Chowanadisai et al., 2006). Some aspects of TNZD resemble the more severe disorder acrodermatitis enteropathica (AEZ; 201100), an autosomal recessive disorder caused by mutation in the zinc transporter SLC39A4 (607059). However, infants with transient neonatal zinc deficiency do not require zinc supplementation following weaning and have normal zinc absorption, whereas those with AEZ require lifelong zinc supplementation (summary by Chowanadisai et al., 2006).

GRIDHH is an autosomal recessive multisystem disorder characterized by poor overall growth, impaired intellectual development, hypotonia, and variable liver dysfunction. Additional features, such as seizures and hearing loss, may also be present (summary by Kopajtich et al., 2016).