High prevalence of the hemochromatosis-associated Cys282Tyr HFE gene mutation in a healthy Norwegian population in the city of Oslo, and its phenotypic expression

Background: Previous studies have shown that 5%-10% of white subjects are h eterozygous for the HFE gene C282Y mutation, which is associated with hemoc hromatosis. The aim of our study was to determine the prevalence of heteroz ygosity and homozygosity for the C282Y HFE gene mutation and its phenotypic expression in a group of healthy Norwegians. Methods: Pasting blood sample s were obtained from 505 unrelated hospital employees. Serum iron, transfer rin, and serum ferritin were measured. Transferrin saturation was calculate d. The presence of HFE gene mutation was determined with a polymerase chain reaction-based analysis. Results: Two of the 505 subjects (0.4%) were homo zygous and 75 (14.9%) were heterozygous for the C282Y mutation. Median seru m ferritin among the heterozygotes was 59 mu g/l, compared with 47 mu g/l a mong individuals without the C282Y mutation (P=0.12). Median transferrin sa turation among the heterozygotes was 31%, compared with 24% among individua ls without C282Y mutation (P < 0.001). Twenty-three individuals (4.6%) had a serum ferritin level greater than or equal to 200 mu g/l. Eight of these (35%) had the C282Y mutation: two homozygotes and six heterozygotes. Transf errin saturation greater than or equal to 50% was observed in 25 individual s (5.0%). Twelve of these (48%) had the C282Y mutation; two were homozygote s and 10 heterozygotes. Only eight individuals (1.6%) had a transferrin sat uration >60%: one homozygote, five heterozygotes, and two individuals witho ut mutation. Conclusions: Fifteen per cent of a healthy Norwegian populatio n is heterozygous for the HFE gene mutation C282Y. This is among the highes t reported prevalence values among healthy individuals. Half of the subject s with transferrin saturation greater than 50% were carriers of the C782Y m utation.