Table 3.

Classification of iron overload

Hereditary hemochromatosis and related disorders
Hereditary hemochromatosis	Type 1
	HFE gene (6p21.3) mutation
	Type 2
	Subtype A: hemojuvelin gene (1q21) mutation
	Subtype B: hepcidin gene (19q13) mutation
	Type 3
	Transferrin receptor 2 gene (7q22) mutation
	Type 4
	Ferroportin gene (2q32) mutation
Ferritin gene mutation	H-ferritin gene mutation (mRNA iron-responsive-element mutation)
DMT1 gene mutation
Ceruloplasmin gene mutation
Atransferrinemia	Transferrin gene mutation
Secondary iron overload
Ineffective erythropoiesis	Thalassemia, sideroblastic anemia, myelodysplastic syndromes
Administration of iron for long periods	Take orally or intravenous injection
Transfusion for long periods
Dietary iron overload
Liver dysfunction	Alcoholic liver injury, chronic hepatitis (type C), non-alcoholic steatohepatitis
Others	Porphyria