London, Apr 14 : The discovery of the gene behind a rare form of inherited iron deficiency may offer clues to iron deficiency in the general population, says a new study.
Iron deficiency, one of the most common nutritional deficiencies, is the leading cause of anaemia in humans, and now researchers have found that the cause of this deficiency may lie in genes.
The researchers have discovered a gene, called TMPRSS6, for a rare form of inherited iron deficiency, which can be the reason behind iron deficiency in the general population, especially those which are non-responsive to iron supplements, paving the way for a new treatment approach.
Usually, it is possible to overturn this deficiency using oral iron supplements, but since a long time, Mark Fleming, MD, DPhil, interim Pathologist-in-Chief at Children's Hospital Boston and his colleagues have come across a number of children with iron deficiency anaemia who didn't respond to oral supplements, with a poor response to intravenous iron.
Their condition was called, iron-refractory iron-deficiency anaemia (IRIDA). While the children showed good dietary habits and did not have any condition that might interfere with iron absorption or cause chronic blood loss, still they including their siblings showed evidence of anaemia since early stages. This made the researchers to conclude that genetics was a controlling factor for iron deficiency.
"After nearly 15 years, we finally had enough families that we could begin to think about positionally cloning the gene for the disorder," Nature quoted Fleming, as saying.
For the study, the researchers studied five extended families with more than one chronically iron-deficient member and discovered a large number of mutations in a gene called TMPRSS6 (transmembrane serine protease S6) in all of these families, as well as several patients without a family history of the disorder.
"Our observations suggest that more common forms of iron deficiency anemia may have a genetic component," said one of the authors of the study.
While the mechanism behind this condition is still unknown, it is the deficiency of the TMPRSS6 protein, that leads to the production of a large amount of hepcidin, a hormone that inhibits iron absorption by the intestine.
Usually, hepcidin is known to be released to protect the body against iron overload, but patients with IRIDA make large amounts of hepcidin even after being iron deficient.
"People with this disorder make too much hepcidin, putting the brakes on iron absorption inappropriately," said Fleming.
The researchers concluded that as TMPRSS6 regulates hepcidin, it may open up new avenues for therapy.
The finding of this study was published online by the journal Nature Genetics.