Hereditary hemochromatosis is not an uncommon condi¬tion. Approximately 10% of individuals of European and particularly Celtic background are heterozygous carriers who only develop iron overload if there is a second defect added to environmental and nutritional factors.
Homozygosity is about 1 in 400. Fortunately, the num¬ber of individuals affected clinically is much less than predicted by the genetic frequency, perhaps, because of variable penetrance and other unknown factors. The fre¬quency of the clinical disease was estimated to be roughly 1 in 5000 in the Pacific Northwest of the United States and 1 in 500 and 1 in 1000 in autopsy series in Scotland and Sweden, respectively. The majority of affected homo-zygotes do not exhibit signs or symptoms; the disease may therefore go undetected. The development of clinical hemochromatosis with damage to organs usually requires a double dose of the mutant gene and affected parents are homozygous. Individuals of Asian and African background are rarely affected.
HEMOCHROMATOSIS IS A CONDITION CAUSED by a genetic defect in which excessive amounts of iron are absorbed in the small intestine and deposited in tissues and organs of the body. Iron overload has several causes one of which is repeated and excessive blood transfusions, as may occur in individuals with sickle cell anemia and beta-thalassemia major. Also, excessive alcohol consumption may increase the blood levels of iron because alcohol stimulates iron absorption. In addition, red wines contain increased amounts of iron. The con¬tainers in which alcoholic beverages are kept may also contain iron and increase the iron content of the beverage. The use of cooking utensils with an iron base from which iron may leach can increase blood levels of iron and deposition in the tissues. Such a condition was noted several years ago in the Bantus who used iron pots for preparation of meals.

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