The world’s largest long-term study of people with a genetic blood disorder has found that men with a specific pair of genes are 30 times more likely than women to develop complications, including major organ damage to the liver and heart, as a result of blood iron overload, or haemochromatosis. Christine McLaren, professor of epidemiology at UC Irvine and study investigator, said her work is the first to quantify how many people carrying the most common genes for haemochromatosis will develop disease. While a common concern for women is having too little iron, this study clearly demonstrates that far more men need to be concerned about absorbing too much iron than previously thought. Results appear in the Jan. 17 issue of the New England Journal of Medicine.