|
Page: Treatment
Main article
| Home > Blood Disorders > Treatment |
Early diagnosis is important because the late effects of iron accumulation can be wholly prevented by periodic phlebotomies (by venesection) comparable in volume to blood donations. Treatment is initiated when ferritin levels reach 300 micrograms per litre (or 200 in nonpregnant premenopausal women).
Every bag of blood (450-500 ml) contains 200-250 milligrams of iron. Phlebotomy (or bloodletting) is usually done at a weekly interval until ferritin levels are less than 50 nanograms per millilitre. After that, 1-4 donations per year are usually needed to maintain iron balance.
Other parts of the treatment include:
* Treatment of organ damage (heart failure with diuretics and ACE inhibitor therapy).
* Limiting intake of alcoholic beverages, vitamin C (increases iron absorption in the gut), red meat (high in iron) and potential causes of food poisoning (shellfish, seafood).
* Increasing intake of substances that inhibit iron absorption, such as high-tannin tea, calcium, and foods containing oxalic and phytic acids (these must be consumed at the same time as the iron-containing foods in order to be effective.)
Haemochromatosis
The gene that controls the amount of iron absorbed from food is called HFE. The HFE gene has two common mutations, C282Y and H63D.
Inheriting just one of the C282Y mutations (heterozygous) makes a person a carrier who can pass this mutation onward. One mutation may lead to slightly excessive iron absorbtion but usually haemochromatosis does not develop.
In the United States, most people with haemochromatosis have inherited two copies of C282Y — one from each parent — and are homozygous for the trait. Mutations of the HFE gene account for 90% of the cases. This gene is closely linked to the HLA-A3 locus. Homozygosity for the C282Y mutation is the most important one, although the heterozygosity C282Y/H63D mutations are also associated to disease (both conditions are sufficient to reach the diagnosis). Carriers of a single copy of either gene have a very slight risk of haemochromatosis when other factors contribute, but are otherwise healthy.
Even if an individual has both copies of the abnormal gene the risk of actual clinical haemochromatosis is low (between 1—25%) due to incomplete penetrance. The variability in these estimates is probably due to different populations studied and how penetrance was defined.
Other genes that cause haemochromatosis are the autosomal dominant SLC11A3/ferroportin 1 gene and TfR2 (transferrin receptor 2). They are much rarer than HFE-haemochromatosis.
Recently, a classification has been developed (with chromosome locations):
* Haemochromatosis type 1 (Mendelian Inheritance in Man (OMIM) 235200): "classical" HFE-haemochromatosis (6p21.3).
* Haemochromatosis type 2 (Mendelian Inheritance in Man (OMIM) 602390): juvenile haemochromatosis :
o Type 2A:(Mendelian Inheritance in Man (OMIM) 602390): mutations in hemojuvelin ("HJV", also known as HFE2)
o Type 2B (Mendelian Inheritance in Man (OMIM) 606464): mutation in hepcidin antimicrobial peptide (HAMP) or HFE2B (19q13)
* Haemochromatosis type 3 (Mendelian Inheritance in Man (OMIM) 604720): transferrin receptor-2 (TFR2 or HFE3, 7q22).
* Haemochromatosis type 4 (Mendelian Inheritance in Man (OMIM) 604653): autosomal dominant haemochromatosis (all others are recessive), ferroportin (SLC11A3) gene mutation (2q32).
• Blood Disorders - Haemochromatosis...
• Blood Disorders - History...
• Blood Disorders - Signs and Symptoms...
• Blood Disorders - Diagnosis...
• Blood Disorders - Epidemiology...
• Blood Disorders - Genetics...
• Blood Disorders - Pathophysiology...
• Blood Disorders - Complications...
• Blood Disorders - Treatment...
|
|
Important notice:
The content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other
qualified health provider with any questions you may have regarding a medical condition.
|