Background. Hereditary hemochromatosis is one of the most common autosomal recessive diseases. Aim of the study. 1. To establish frequency of C282Y and H63D mutations in the HFE gene (the hemochromatosis gene) in general population of the Czech Republic and in patients with hemochromatosis. 2. To find out whether hemochromatosis in homo- or heterozygous state plays a role in the pathogenesis of rheumatic diseases. Methods and Results. In 32 patients with hereditary hemochromatosis, in 84 patients with polymyositis or dermatomyositis, in 246 patients with juvenile idiopathic arthritis and in 481 persons of the control group the presence of HFE gene mutations was etablished. The HFE gene mutations were screened for by restriction enzyme analysis performed on PCR amplified products. In the control group, 6.86 % carriers of the C282Y mutation and 26.61 % those of H63D were found. Homozygous C282Y or H63D mutation was found in 90.6% (p<0.001) of patients with hemochromatosis. Heterozygous C282Y mutation was found in 12.2 % (p<0.05) of patients with juvenile idiopathic arthritis. We didn@t detected higher prevalence of HFE gene mutations in patiens with polymyositis and dermatomyositis. Conclusions. Results of this study show that heterozygosity for C282Y mutation may be a risk factor for juvenile idiopathic arthritis but not for polymyositis and dermatomyositis.

        Key words: hemochromatosis, HFE gene, polymyositis, dermatomyositis, juvenilie idiopathic arthritis, C282Y mutation, H63D mutation.