Non-HFE hemochromatosis.

The term "non-HFE hemochromatosis" (non-HFE HC) refers to several phenotypically similar but genetically distinct forms of hereditary hemochromatosis affecting individuals without pathogenic mutations of HFE. The involved genes are, sinsu strictu, transferrin receptor 2 (TfR2), hemojuvelin (HJV), and hepcidin (HAMP). Non-HFE HC share common pathogenic and clinical features with HFE HC. However, depending on the role of the affected gene in iron trafficking, the clinical onset may be earlier and phenotypic expressivity more severe than classic HC. Other forms of hereditary iron overload have distinct pathogenesis and phenotype. The most prevalent of these forms is "ferroportin disease," characterized by autosomal dominant trait, predominant reticuloendothelial cell iron overload, and mild organ damage. Non-HFE HC gene products, while responsible for rarer cases of HC as compared with HFE, are much more central than HFE in human iron homeostasis and understanding their function will greatly advance our comprehension of iron trafficking in health and disease.