Israel Medical Association Journal

Background: Genetic hemochromatosis leads to iron overload in many tissues and may lead to liver cirrhosis and hepatocellular carcinoma. Early diagnosis and therapy are crucial. Since 80–100% of hemochromatosis patients of European origin are homozygous for a cysteine to tyrosine exchange in the HFE gene at codon 282, genetic screening might be useful. Representative population studies are needed to evaluate the phenotype of people heterozygous and homozygous for the C282Y mutation.

Objective: To determine the correlation between parameters of iron metabolism and the hemochromatosis genotype in a large population-based study.

Methods: A representative population-based survey, the Diabetomobil study, analyzed 5,083 German probands. Serum transferrin saturation and ferritin levels were determined, and the C282Y mutation of the HFE gene was analyzed by restriction fragment length polymorphism- polymerase chain reaction analysis.

Results: Nine of 373 probands with a transferrin saturation > 55% (2.4%) and none of 264 randomly selected probands with a transferrin saturation £ 55% (0%) were homozygous for the C282Y mutation. Three of the nine homozygous probands had ferritin values less than 250 µg/L. The frequency of the heterozygous genotype was 8.8%, and the percentage of heterozygous probands increased with increasing levels of transferrin saturation.

Conclusion:We propose a population screening strategy with an initial transferrin saturation test, followed by genotyping for the C282Y mutation if the transferrin saturation is above 55%, regardless of the ferritin level. Heterozygous individuals with higher transferrin saturation values may be protected against iron loss but may also be more susceptible for certain liver diseases, depending on the simultaneous prevalence of other diseases.
 

Systemic infection or inflammation causes a decrease in intestinal iron absorption and impairs the release of recycled iron from macrophages. Decreased availability of iron may deny this essential element to invading pathogens and may inhibit their multiplication and other metabolic processes but also results in anemia of chronic disease. This article reviews recent discoveries that shed light on the regulation of iron metabolism during infection and iron overload, and point to the central role of a newly discovered peptide, hepcidin. Evidence to date indicates that hepcidin is a negative regulator of intestinal iron absorption, placental iron transport, and the release of iron from macrophages that recycle iron from senescent red cells. It may also be the central mediator of iron sequestration during infections and inflammatory states and the mediator of anemia of chronic disease. Rapid progress in this area is a good example of the beneficial effects of improvements in peptide analysis and chemistry, advances in genomics, and the increasing use of transgenic mice to determine the function of newly discovered genes and proteins.