Prevalence of Iron Overload in Central Sweden

Abstract

An increase in the iron content of food may be harmful to people with genetic hemochromatosis. We studied the prevalence of this disorder in Sweden, which is the country with the world's highest iron fortifhtion of food. Serum ferritin and transferrin (TIBC) saturation levels were used as initial screening methods. Three (0.5 %) of 623 males aged 30-39 years were found to have genetic hemochromatosis. Family studies revealed 10 additional homozygotic family members. A prevalence of 0.5 % of homozygotes (47 implies a gene frequency (4) of 6.9% or a heterozygote frequency ( 2 x q ) of 13.8%. The high gene frequency may be explained by a possible genetic advantage of heterozygotes in the past. We conclude that idiopathic hemochromatosis is not as rare as previously thought. Affected persons should be detected and treated before irreversible organ damage occurs. This study demonstrates that serum ferritin levels together with TIBC saturation levels are adequate methods for screening populations. Abbreviations:TIBC= transferrin, HLA= histocompatibility antigen, DF=desferrioxamine. S-ALAT= serum alanine aminotransferase. N Engl J Med 1979; 301: 1291. 24. Bezwoda WR, Bothwell TH. Derman DP et al. Effect of diet on the rate of iron accumulation in idiopathic haemochromatosis. S Afr Med J 1981; 5 9 219-22. ASSW J 1976; 114 417-21. Acra Med Scand 213

Screening for Iron Overload Using Transferrin Saturation

“…If in-patients are excluded for the reason mentioned above, 11 out of approximately 4700 out-patients and blood donors were found to have iron overload. This prevalence figure of 0.24% represents a gene frequency of 0.05, which concurs well with those reported from Utah, USA ( l l ) , Brittany, France (15) and Central Sweden (4). It disagrees with the figure of 0.01% reported in the classic work of Finch and Finch (14).…”

Prevalence of Hemochromatosis in Finland

“…The prevalence rate estimate in our study is not very far from the rate (100/100000) obtained from southern Sweden (11). The much higher prevalence rates (240-500/100000) also reported (8,9) could have resulted from selection of study populations or clustering of the disease and use of more liberal criteria for hemochromatosis, and cannot be considered applicable to the Finnish population.…”

Was the C282Y mutation an Irish Gaelic mutation that the Vikings helped disseminate?*

“…Serum iron, transferrin saturation and serum ferritin were determined by routine methods. Iron stores were measured by quantitative phlebotomy as previously described (26). HLA typing was performed by the method of Vartdal (27) and HFE genotype analysis according to Feder et al.…”