Background: Zinc is an essential trace element required by all living organisms because of its vital role both as a structural component of proteins and as a cofactor in enzymatic catalysis. The importance of zinc in human metabolism characterized by the effects of zinc deficiency, include a diminished immune response, retarded healing and neurological disorders. This study aimed to review the effects of zinc deficiency in onset of inherited disorders.

Materials and Methods: A comprehensive search was done in academic databases (e.g. Pubmed)

Results: While zinc deficiency is commonly caused by dietary factors, several inherited defects of zinc metabolism have been identified. Acrodermatitis enteropathica is the most commonly described inherited condition found in humans. According to some reports, this disorder is associated with mutations in the hZIP4 gene. Another inherited form of zinc deficiency occurs in the lethal milk mouse syndrome, where a mutation in ZnT4 gene, a member of the SLC30 family of transmembrane proteins results in impaired secretion of zinc from the mammary gland into milk. A similar disorder to the lethal milk mouse occurs in humans.

Conclusion: The presence of several minor phenotypic differences between the zinc deficiency in humans and mice suggests that the human condition is caused by defects in genes that are yet to be identified. Taking into account the fact that there are no definitive tests for zinc deficiency detection and that this disorder can left undiagnosed, it is likely that mutations in other genes may underlie additional inherited disorders of zinc deficiency.

Background: Environmental pollution and also the continuous exposure of human beings to toxic heavy metals (e.g. Mercury, Cadmium and Lead) is a seriously growing problem throughout the world. Exposure to metals has risen dramatically in the last fifty years as the result of exponential increase in the use of heavy metals in industrial processes and products. Although we are usually exposed to metals in a latent manner and in small daily doses, as they are present in various environmental components, foods and materials. Heavy metals occur as natural constituents of the earth shell, and are persistent environmental contaminants since they cannot be degraded or destroyed. This study reviews the effects of Lead as one of these heavy metals on different parts of the human body.

Materials and Methods: Pubmed database has been searched to prepare the review.

Results: Lead is the most significant toxin of the heavy metals, and its inorganic form is absorbed through ingestion by food, water, and inhalation. When ingested, they combine with the body’s biomolecules (e.g. proteins and enzymes) to form stable biotoxic compounds, thereby mutilating their structures and hindering them from the bioreactions of their functions. Lead poisoning causes inhibition of the synthesis of haemoglobin, results in dysfunctions in the kidneys, joints and reproductive systems, cardiovascular system and acute or chronic damage to the central and peripheral nervous system.

Conclusion: Lead through poor development of the grey matter of the brain affects children health, thereby resulting in poor intelligence quotient. Moreover, acute and chronic effects of Lead result in psychosis.