HJV and hereditary hemochromatosis: Other types of hereditary hemochromatosis are caused by mutations in the transferrin receptor-2 gene (TfR2) (Camaschella et al., 2000), hemojuvelin gene (HJV) (Papanikolaou et al., 2004), hepcidin gene (HAMP) (Roetto et al., 2003), and the ferroportin gene (SCL40A1) (Pietrangelo, 2004).