[hemo + chromatosis]
A genetic disease marked by excessive absorption and accumulation of iron in the body. The disease is caused by one of several recessive mutations that result in excessive absorption of iron from the gastrointestinal tract. It is not caused by secondary iron overload, as may occur in patients who have received multiple transfusions or who have hemolytic anemia. The disease is often diagnosed before it causes symptoms.
Between 0.25 and 1.9% of the population is homozygous for the genes that cause hemochromatosis.
At the time of diagnosis, the patient may be asymptomatic. Symptomatic patients may experience weakness, fatigue, arthralgias, abdominal pain, liver failure (cirrhosis), symptoms of diabetes mellitus or heart failure, thyroid disorders, or impotence. These symptoms are caused by the deposition of excess iron into multiple organ systems.
Physical findings include gray or bronzed skin pigmentation changes, enlarged liver, arthritis, signs of congestive heart failure, and in males, testicular atrophy. Laboratory studies used to screen for the disease include transferrin saturation or ferritin tests. Liver biopsies from affected persons show excessive stainable iron. Genetic testing is available to identify patients with the most common forms of hemochromatosis.
HEMOCHROMATOSIS With excessive quantities of iron found in liver cells
Treatment includes phlebotomy (blood drawing) done at regular intervals until the patient's iron stores drop to below normal. Typically, the ferritin level is monitored to ensure that this has occurred. Initially, approximately 1 unit of blood is removed each week until the desired ferritin level is reached. Maintenance therapy consists of removal of blood at 1- to 4-month intervals. Iron chelators such as deferoxamine are used if phlebotomy is not possible, but they are much less effective at decreasing iron stores than is blood drawing.
Blood removed from patients with iron overload cannot be used for transfusion.
The need for phlebotomy and its role in the removal of excess iron are explained to the patient. To prevent dizziness or hypotension, the patient is encouraged to drink plenty of fluids and to abstain from vigorous exercise for the first 24 hr after the procedure. Patients should be educated to avoid taking iron supplements or vitamin C, both of which may increase body stores of iron.
SYN: SEE: bronze diabetes; SEE: iron storage disease
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