What percentage of C282Y homozygotes develop clinical hemochromatosis?

Penetrance is incomplete: only 10–33% of C282Y homozygous males and 1–5% of females develop clinical disease (iron overload with organ damage). Transferrin saturation >45% with ferritin >300 ng/mL (men) or >200 ng/mL (women) indicates iron overload requiring phlebotomy.

When should liver biopsy be performed in hemochromatosis?

Liver biopsy is indicated when ferritin >1000 ng/mL or ALT/AST elevated, to assess for fibrosis/cirrhosis. Patients with established cirrhosis require 6-monthly liver ultrasound and AFP for HCC surveillance—hemochromatosis cirrhotics have 200× increased HCC risk.

Hereditary Hemochromatosis C282Y Phenotype Probability

Estimate clinical expression probability in HFE C282Y homozygous hereditary hemochromatosis using transferrin saturation, ferritin, age, and sex to predict who requires phlebotomy therapy.

Use the full interactive calculator below, or

Hereditary Hemochromatosis C282Y Phenotype Probability

Frequently Asked Questions

What percentage of C282Y homozygotes develop clinical hemochromatosis?

When should liver biopsy be performed in hemochromatosis?