Which laboratory tests are recommended for screening hereditary hemochromatosis?

Laboratory Tests for Hemochromatosis Screening

The first-step screening for hereditary hemochromatosis requires measuring both transferrin saturation (TS) and serum ferritin together—never rely on a single test. 1, 2

Initial Screening Tests

Primary Screening Panel

• Transferrin saturation (TS): The most important initial test

  • Abnormal threshold: ≥45% 1, 2
  • Normal range: 20-50% 2

• Serum ferritin: Essential companion test

  • Abnormal thresholds:
    • Men: >300 μg/L 2
    • Women: >200 μg/L 2
  • Normal ranges:
    • Men: 20-200 μg/L 2
    • Women: 15-150 μg/L 2

Both tests must be ordered together because either can be abnormal in hemochromatosis, and relying on a single test misses cases. 2 The 2022 EASL guidelines achieved 100% consensus that TS and ferritin together constitute the first step in testing 1.

Additional Iron Parameters (Optional)

The following provide supplementary information for differential diagnosis but are not required for initial screening 1:

• Serum iron concentration
• Total iron binding capacity (TIBC) or transferrin level

What NOT to Measure

Hepcidin measurement is NOT recommended (100% consensus) 1. Despite its pathophysiologic role, hepcidin testing has no established clinical utility for diagnosis 3.

When to Proceed to Genetic Testing

If either TS ≥45% OR ferritin is elevated above normal limits, proceed immediately to HFE gene mutation analysis after obtaining informed consent 1, 2.

Specific Genetic Testing Approach

For individuals of European ancestry with biochemical iron overload:

• Test for p.C282Y mutation in HFE gene (primary mutation) 1
• Consider p.H63D testing only in special clinical situations 1

The thresholds that trigger genetic testing are:

• Females: TS >45% AND ferritin >200 μg/L 1
• Males: TS >50% AND ferritin >300 μg/L 1
• OR persistently elevated TS alone, even without elevated ferritin 1

Target Populations for Screening

High-Priority Groups (Screen These)

1. First-degree relatives of diagnosed hemochromatosis patients: Screen with both iron studies AND genetic testing simultaneously at a single visit 2
2. Patients with suggestive symptoms: unexplained chronic liver disease, elevated liver enzymes, arthritis, cardiomyopathy, diabetes, skin pigmentation, hypogonadism 2
3. Patients with unexplained persistently elevated TS 1

Do NOT Screen

Average-risk population screening is NOT recommended 2. The clinical penetrance of C282Y homozygosity is low, making widespread screening not cost-effective 2.

Common Pitfalls to Avoid

1. Ordering ferritin alone: Ferritin can be elevated from inflammation, liver disease, alcohol use, or metabolic syndrome without iron overload. Without TS, you cannot distinguish hemochromatosis from these conditions 2.

2. Dismissing normal TS with elevated ferritin: Iron overload can exist with normal TS, particularly in non-HFE hemochromatosis or C282Y/H63D compound heterozygotes 2.

3. Ordering genetic testing first: Always start with iron studies (TS and ferritin), then proceed to genetics only if biochemically abnormal 2. This approach is more cost-effective than genetic testing first 4.

4. Testing children of probands without testing the other parent: If the other parent tests negative for HFE mutations, the child is an obligate heterozygote and needs no further testing 2.

Clinical Context

The 2022 EASL guidelines 1 represent the most recent expert consensus and align closely with the 2011 AASLD guidelines 2, which remain the standard in North America. Both emphasize that transferrin saturation is the diagnostic hallmark of hemochromatosis 5, as it reflects the expanded plasma iron pool that characterizes this condition.

Serum ferritin >1000 μg/L predicts increased risk of cirrhosis and helps determine who needs liver biopsy, but this is for staging disease severity, not initial screening 2.