The spectrum of known disorders of
iron metabolism has expanded dramatically over the past few years. Identification of HFE, the gene most commonly mutated in patients with hereditary
hemochromatosis, has allowed molecular diagnosis and paved the way for identification of other genes, such as TFR2, that are important in non-HFE-associated
iron overload. There are clearly several other, unidentified,
iron overload disease genes yet to be found. In parallel, our understanding of
iron transport has expanded through identification of Fpn1/Ireg1/MTP1, Sfxn1 and DCYTB: Ongoing studies of
Friedreich's ataxia,
sideroblastic anemia,
aceruloplasminemia and neurodegeneration with brain-
iron accumulation are clarifying the role for
iron in the nervous system. Finally, as the number of known
iron metabolic genes increases and their respective functions are ascertained, new opportunities have arisen to identify genetic modifiers of
iron homeostasis.