Type 3 hereditary hemochromatosis in a patient from sub-Saharan Africa: Is there a link between African iron overload and TFR2 dysfunction?

摘要

To the editor: Hereditary hemochromatosis (HHC) is a common genetic trait that increases the risk of developing systemic iron overload. The disorder is caused by mutations in genes coding various proteins involved in the regulation of iron access into the blood. In HHC, excessive iron storage may result in progressive multiorgan damage, which can be treated with phlebotomy. HHC is well defined in Northern Europe. In this population, most affected individuals share the HFE recessive p.C282Y mutation, which is the most common genetic cause for classic (type 1) HHC. It is presumed that p.C282Y appeared for the first time in the Celtic or Viking population more than 2000 years ago and followed their migrations. Accordingly, p.C282Y is less frequent in Southern Europeans, Native Americans, American of African descent, Pacific Islanders, and Asians, and nearly absent in Southern Africans. Mutations in 4 additional genes (namely HJV, HAMP, TFR2 and SLC40A1) account for different, rarer forms of HHC (type 2A, type 2B, type 3, type 4), and can be found also in patients outside Northern Europe.