[Hereditary hemochromatosis].
Hereditary hemochromatosis is an inherited autosomal recessive disease, associated to a mutation in the recently described HFE gene, which is located on the short arm of chromosome 6. The product of this gene combines with the beta-2-microglobulin and the ferritin receptor, and regulates the iron absorption in the small intestine crypt cells. It is possible that the mutation may cause the increased iron uptake by the intestinal cells. The disease is very much common in men after the forties, and its expression is influenced by concomitant alcoholism, iron rich diet, oral and parenteral iron administration, menstrual blood loss or abnormal hemorrhages, blood donations, pregnancy, lactation, and iron malabsorption clinical conditions, like celiac disease. Many patients are asymptomatic, and the diagnosis may be suspected by hepatomegaly of unknown cause, abnormal iron metabolism tests, increased serum aminotransferase levels, diabetes mellitus, and anonymous arthropathy. Less commonly hereditary hemochromatosis presented by symptoms and signs of chronic liver disease, or by the classic triad described by Trousseau skin pigmentation, hepatomegaly and diabetes mellitus. The diagnosis is confirmed by the increased serum ferritin levels and transferrin saturation, and the stainable iron in hepatocytes, measured by scale devised by Scheuer et al, or the measurement of the hepatic iron. The C282Y mutation was found in 64 to 100% of patients; eventually, subjects with hepatic iron overload identical to hereditary hemochromatosis has no mutation, and homozygous for the C282Y mutation do not express iron overload. Iron is best and quickly removed by weekly or twice-weekly phlebotomy of 500 ml, containing approximately 250 mg iron. One to 3 years of weekly phlebotomy may be required to reduce stores to normal. As a guide to long-term maintenance therapy, is recommended phlebotomy every 3 months and the serum ferritin level should be maintained by less than 50 ng/ml.
Dantas
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Departamento de Clínica Médica da Universidade Federal de Santa Catarina.
D000328:Adult; D000428:Alcohol Drinking / Q000009:adverse effects; D019943:Amino Acid Substitution; D015913:Chelation Therapy; D002896:Chromosomes, Human, Pair 6 / Q000235:genetics; D015897:Comorbidity; D003676:Deferoxamine / Q000627:therapeutic use; D003937:Diagnosis, Differential; D005260:Female; D005293:Ferritins / Q000097:blood; D006680:HLA Antigens / Q000235:genetics / Q000502:physiology; D006432:Hemochromatosis / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics* / Q000628:therapy; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000502:physiology; D006801:Humans; D007408:Intestinal Absorption; D007501:Iron / Q000493:pharmacokinetics; D007502:Iron Chelating Agents / Q000627:therapeutic use; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D018962:Phlebotomy; D017354:Point Mutation; D015995:Prevalence
C103673:HFE protein, human; D006680:HLA Antigens; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I; D007502:Iron Chelating Agents; D008565:Membrane Proteins; D005293:Ferritins; D007501:Iron; D003676:Deferoxamine