SLC40A1 and hemochromatosis type 4: Hemochromatosis associated with mutation in FPN1 can result in two different types of iron loading: one type is phenotypically indistinguishable from classical HFE hemochromatosis, in that the patients have both an elevated transferrin saturation and serum ferritin, while the other type termed “ferroportin disease” is associated with microcytic anemia, a raised serum ferritin and iron deposition in macrophages rather than hepatocytes [23].