Like most nutrients, iron is good for people in the right doses. When the body has enough iron, our cells stop absorbing it from food; if there is too little, they absorb more. This system breaks down in the most common inherited disease in the Western world: hemochromatosis, which affects about one in every 250 people and is often fatal if it is not recognized and treated. Now researchers at the European Molecular Biology Laboratory in Heidelberg (EMBL) and Harvard Medical School (U.S.) have linked the response of a gene in the liver to the disease. The study, which appears in the current issue of Nature Genetics, is changing our understanding of how hemochromatosis develops.
"Untreated iron overload can result in liver cancer, heart disease, or other fatal conditions," says Martina Muckenthaler, a staff scientist at EMBL in the research group of Matthias Hentze. "The mutation that causes the disease was thought to have its major effects in the intestine, where cells absorb iron from food. Our current study has changed that picture."
Sufferers of hemochromatosis have inherited a defective copy of a gene called Hfe from each parent. The mutation can be traced back several centuries into Celtic history, where it originated in a single person who passed it down to his or her children. It has now spread throughout Europe and the Western world.
The defect leads a person's intestine to absorb too much iron from his or her diet. Over the course of many years, this builds up, and by middle age, the overload may be very serious. Hentze and his group at EMBL have been trying to trace these effects back to their molecular causes.
Until now, most researchers have thought that the problem stems from a faulty intestinal signal that there is too little iron, leading cells in the intestines to produce more transport proteins that draw iron inside.
By combining two approaches, the EMBL and Harvard teams have now rewritten this model. TPage: 1 2 3 Related biology news :1
Contact: Russ Hodge
European Molecular Biology Laboratory
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