Featured Research

from universities, journals, and other organizations

A Genetic Cause For Iron Deficiency

Date:
April 15, 2008
Source:
Children's Hospital Boston
Summary:
The discovery of a gene for a rare form of inherited iron deficiency may provide clues to iron deficiency in the general population -- particularly iron deficiency that doesn't respond to iron supplements -- and suggests a new treatment approach.

The discovery of a gene for a rare form of inherited iron deficiency may provide clues to iron deficiency in the general population -- particularly iron deficiency that doesn't respond to iron supplements - and suggests a new treatment approach.

Related Articles


Iron deficiency is the most common nutritional deficiency and the leading cause of anemia in the United States.* Most cases are easily reversed with oral iron supplements, but over the years, Mark Fleming, MD, DPhil, interim Pathologist-in-Chief at Children's Hospital Boston, and pediatric hematologist Nancy Andrews, MD, PhD, formerly of Children's and now Dean of Duke University School of Medicine, had been referred a number of children with iron deficiency anemia who didn't respond to oral supplements, and only poorly to intravenous iron.

The cause of their condition -- termed iron-refractory iron-deficiency anemia (IRIDA) --was a mystery. The children all had good diets, and none had any condition that might interfere with iron absorption or cause chronic blood loss, the most common causes of iron deficiency. All had evidence of anemia from a very early age, and many also had siblings with iron deficiency anemia. Seeing reports of several similarly afflicted families in the medical literature, Fleming and Andrews were convinced that genetics was a factor.

"After nearly 15 years, we finally had enough families that we could begin to think about positionally cloning the gene for the disorder," says Fleming.

Fleming and Andrews, experts in iron metabolism, and their colleagues Karin Finberg, MD, PhD, and Matthew Heeney, MD, studied five extended families with more than one chronically iron-deficient member. They found a variety of mutations in a gene called TMPRSS6 (the acronym stands for transmembrane serine protease S6) in all of these families, as well as several patients without a family history of the disorder.

Although IRIDA is quite rare, the authors believe it might be the extreme end of a broad continuum of disease, since TMPRSS6 mutations varied widely in the five families and caused different degrees of iron deficiency and anemia.

"Our observations suggest that more common forms of iron deficiency anemia may have a genetic component," says Andrews.

All patients in the study apparently had recessive mutations, since their parents did not have iron deficiency anemia. The investigators now want to determine whether people with just a single abnormal copy of TMPRSS6 have subtler alterations in iron absorption that might not otherwise have come to the attention of a hematologist.

Although the mechanism is still unknown, deficiency of the TMPRSS6 protein causes the body to produce too much hepcidin, a hormone that inhibits iron absorption by the intestine. Normally, hepcidin is produced to protect the body against iron overload -- but patients with IRIDA make large amounts of hepcidin even though they are iron deficient. "People with this disorder make too much hepcidin, putting the brakes on iron absorption inappropriately," Fleming says.

In addition, patients with TMPRSS6 mutations cannot make new red blood cells efficiently because the iron needed to make them comes from macrophages, and hepcidin causes macrophages to hold on to iron. This explains the patients' poor response to intravenous iron -- the iron is trapped in macrophages and cannot be used for red blood cell production.

The fact that TMPRSS6 regulates hepcidin may open up new avenues for therapy, the researchers say. For example, blocking TMPRSS6 may help patients with iron overload disorders make more hepcidin in order to limit intestinal iron absorption. Conversely, stimulating TMPRSS6 may have therapeutic benefit in certain patients with anemia, particularly those in which hepcidin is overproduced.

The finding was published online by the journal Nature Genetics on April 13. The study was supported by the National Institutes of Health.

*Centers for Disease Control and Prevention. Iron deficiency -- United States, 1999--2000. MMWR 2002;51:897--899.


Story Source:

The above story is based on materials provided by Children's Hospital Boston. Note: Materials may be edited for content and length.


Cite This Page:

Children's Hospital Boston. "A Genetic Cause For Iron Deficiency." ScienceDaily. ScienceDaily, 15 April 2008. <www.sciencedaily.com/releases/2008/04/080413161038.htm>.
Children's Hospital Boston. (2008, April 15). A Genetic Cause For Iron Deficiency. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2008/04/080413161038.htm
Children's Hospital Boston. "A Genetic Cause For Iron Deficiency." ScienceDaily. www.sciencedaily.com/releases/2008/04/080413161038.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
Today's Prostheses Are More Capable Than Ever

Today's Prostheses Are More Capable Than Ever

Newsy (Nov. 26, 2014) Advances in prosthetics are making replacement body parts stronger and more lifelike than they’ve ever been. Video provided by Newsy
Powered by NewsLook.com
From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com
Daily Serving Of Yogurt Could Reduce Risk Of Type 2 Diabetes

Daily Serving Of Yogurt Could Reduce Risk Of Type 2 Diabetes

Newsy (Nov. 25, 2014) Need another reason to eat yogurt every day? Researchers now say it could reduce a person's risk of developing type 2 diabetes. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins