As seen online:
“The prevalence of C282Y homozygosity is approximately 1 case per 200 persons, with elevated levels of serum ferritin and transferrin saturation occurring in 40 to 60% of female homozygotes and in 75 to 100% of male homozygotes.9–13 An elevated serum ferritin level is a necessary but not sufficient prerequisite for the diagnosis of iron overload, which can be objectively documented either by liver biopsy with determination of quantitative hepatic iron levels or by quantitative phlebotomy.14”
— from Iron-Overload–Related Disease in HFE Hereditary Hemochromatosis | New England Journal of Medicine as of 22 September 2026