Hereditary hemochromatosis in the post-HFE era

Abstract

Following the discovery of the HFE gene in 1996 and its linkage to the iron overload disorder hereditary hemochromatosis (HH) there have been profound developments in our understanding of the pathogenesis of the biochemical and clinical manifestations of a number of iron overload disorders. This article provides an update of recent developments and key issues relating to iron homeostasis and inherited disorders of iron overload, with emphasis on HFE-related HH, and is based on the content of the American Association for the Study of Liver Diseases Single-Topic Conference entitled "Hemochromatosis: What has Happened After HFE?" which was held at the Emory Convention Center in Atlanta, September 7-9, 2007.

Figures

Figure 1

A) Under normal conditions, plasma transferrin saturation regulates the expression of liver hepcidin via a HFE, TFR2 and BMP-HJV signaling pathway which in turn, is secreted into the blood, binding to FPN in the intestine and macrophages inducing FPN internalization and degradation, limiting intestinal Fe absorption and Fe recycling by macrophages to maintain plasma transferrin saturation. B) In HH, mutations in HFE, HJV and TFR2 impair hepcidin synthesis, increasing FPN levels and Fe release from intestinal cells and macrophages, elevating plasma transferrin saturation and deposition of iron in the liver and other tissues.