Natural History of the C282Y Homozygote for the Hemochromatosis Gene (HFE) With a Normal Serum Ferritin Level

Background & Aims: The discovery of a genetic test for hereditary hemochromatosis has identified many individuals who are homozygous for the C282Y mutation of the HFE gene with a normal transferrin saturation and serum ferritin level. The long-term prognosis, rate of iron accumulation, and surveillance guidelines for these individuals are unknown. Methods: To determine the degree of iron accumulation over time, an updated serum ferritin level was obtained in patients initially identified as homozygous for the C282Y mutation with a normal serum ferritin level. Results: Twenty-two asymptomatic untreated C282Y homozygotes with a normal serum ferritin level were identified, 10 through population screening, 9 through pedigree analysis, and 3 through a general medical work-up. There were 18 women (4 postmenopausal) and 4 men with a median age of 46 years, range 28-76 years. The median follow-up interval was 4 years, range 2-23 years. The serum ferritin levels of 20 of 22 patients remained below the upper limit of normal during the follow-up period. A decline in serum ferritin level was observed in 13 of 22 patients. Three patients had an increase in serum ferritin level of greater than 50%, with only 1 male patient exceeding the upper limit of normal by having a serum ferritin level increase from 295 to 344 mu g/L during a 3-year period. Conclusions: In C282Y homozygotes with a normal ferritin level at the time of diagnosis, 20 of 22 patients failed to show any significant increase in serum ferritin level during a median follow-up of 4 years. This has clinical and economic implications for follow-up and surveillance of this selected population.