What you carry at this position in your DNA and what research says about it.
Iron Overload Risk: 10/10 evidence, 67 publications.
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Sample genotype (not yours): G/G
Typical Iron Levels and Low Hemochromatosis Risk
Two copies of the common G allele mean you do not carry the C282Y mutation. Your body regulates iron absorption normally, and you have no elevated risk for hereditary hemochromatosis.
What this genotype means: Normal dietary iron absorption; Typical baseline ferritin levels; Extremely low risk of genetic iron overload.
Sample genotype (not yours): A/A
High Risk of Hereditary Hemochromatosis
Two copies of the A allele put you at a significantly higher risk of developing hereditary hemochromatosis, a condition where the body absorbs too much iron. Left untreated, this excess iron can build up in organs like the liver and heart.
What this genotype means: Significantly increased dietary iron absorption; High risk of clinical iron overload; Elevated serum ferritin and transferrin saturation.
Sample genotype (not yours): G/A
Hemochromatosis Carrier with Slightly Higher Iron Risk
Carrying one copy of the A allele makes you a carrier for hemochromatosis, which slightly increases your baseline iron levels. While you are highly unlikely to develop full iron overload, you can pass this variant to your children.
What this genotype means: Carrier of the C282Y mutation; Slightly elevated baseline iron markers; Potential to pass the variant to offspring.
Gene function and biological role
Gene Function: The HFE gene encodes the homeostatic iron regulator protein, which plays a critical role in controlling how much iron the body absorbs from food [1]. It acts as a sensor on the surface of cells, interacting with other proteins to regulate the production of hepcidin, the master iron-regulatory hormone [2]. When HFE is functioning normally, it prevents the body from absorbing excess iron and maintains stable systemic iron levels [3]. Mutations in this gene can disrupt this delicate sensing mechanism, leading to uncontrolled dietary iron absorption and tissue accumulation [4].
Variant Impact: The rs1800562 variant, commonly known as the C282Y mutation, is a missense change that replaces the amino acid cysteine with tyrosine at position 282 of the HFE protein [1]. This specific structural alteration prevents the HFE protein from binding to beta-2-microglobulin, which is essential for its transport to the cell surface [5]. Without surface expression of HFE, cells cannot properly signal to produce hepcidin, resulting in continuous, unregulated absorption of dietary iron [3]. This variant is the most common genetic cause of iron overload in populations of Northern European descent [2].
Key Insight: Although carrying two copies of this variant significantly increases iron absorption, many people with this genotype never develop severe clinical symptoms of hemochromatosis.
Location: HFE. Chromosome 6 · 6p22.2 · 26.1 Mb
Origin Story: The C282Y mutation is believed to have originated in a single Celtic or Viking ancestor in Northern Europe several thousand years ago. During the transition to agriculture in the Neolithic era, diets shifted from iron-rich wild foods to iron-poor grains, making iron deficiency anemia a major survival threat. This mutation provided a selective advantage by enhancing dietary iron absorption, helping early European populations survive on iron-poor diets.
Estimated prevalence by population
Global 92.7%; European 87.5%; African 97.8%; East Asian 99.9%; South Asian 99.5%; Americas 96.3%; Ashkenazi 97.3%; Finnish 93.0%; Middle Eastern 100.0%; Amish 91.2%.
Estimated GG genotype frequency.
Global 7.1%; European 12.1%; African 2.2%; East Asian 0.1%; South Asian 0.5%; Americas 3.7%; Ashkenazi 2.7%; Finnish 6.9%; Middle Eastern 0.0%; Amish 8.6%.
Estimated GA genotype frequency.
Global 0.2%; European 0.4%; African < 0.1%; East Asian < 0.1%; South Asian < 0.1%; Americas < 0.1%; Ashkenazi < 0.1%; Finnish 0.1%; Middle Eastern 0.0%; Amish 0.2%.
Estimated AA genotype frequency.
Showing effects for G/G genotype
Rare Genetic Disorders
Inherited Metabolic Disorders
Hemochromatosis. Evidence: 5/10. Source: PMID 20301613. Typical Risk.
Cardiovascular & Metabolic
Blood Cell & Iron Traits
Iron Levels. Evidence: 10/10. Source: PMID 25352340. Typical.
Ferritin Levels. Evidence: 10/10. Source: PMID 21943158. Typical.
Transferrin Saturation. Evidence: 10/10. Source: PMID 25352340. Typical.
Hemoglobin Levels. Evidence: 10/10. Source: PMID 19862010. Typical.
Organ Systems
Liver Function & Disease
Fatty Liver Disease. Evidence: 6/10. Source: PMID 37235137. Typical Risk.
Bone, Joint & Connective Tissue Health
Osteoarthritis. Evidence: 7/10. Source: PMID 30374069. ~1.95x Higher Risk.
Showing effects for A/A genotype
Hemochromatosis. Evidence: 5/10. Source: PMID 20301613. High Risk.
Iron Levels. Evidence: 10/10. Source: PMID 25352340. Elevated.
Ferritin Levels. Evidence: 10/10. Source: PMID 21943158. Elevated.
Transferrin Saturation. Evidence: 10/10. Source: PMID 25352340. Elevated.
Hemoglobin Levels. Evidence: 10/10. Source: PMID 19862010. Elevated.
Fatty Liver Disease. Evidence: 6/10. Source: PMID 37235137. ~1.25x Higher Risk.
Osteoarthritis. Evidence: 7/10. Source: PMID 30374069. Typical Risk.
Showing effects for G/A genotype
Hemochromatosis. Evidence: 5/10. Source: PMID 20301613. Carrier (Low Risk).
Iron Levels. Evidence: 10/10. Source: PMID 25352340. Slightly Elevated.
Ferritin Levels. Evidence: 10/10. Source: PMID 21943158. Slightly Elevated.
Transferrin Saturation. Evidence: 10/10. Source: PMID 25352340. Slightly Elevated.
Hemoglobin Levels. Evidence: 10/10. Source: PMID 19862010. Slightly Elevated.
Fatty Liver Disease. Evidence: 6/10. Source: PMID 37235137. Slightly Higher Risk.
Osteoarthritis. Evidence: 7/10. Source: PMID 30374069. Slightly Higher Risk.
What this genotype means for the people who carry it
Sample genotype: GG (Homozygous)
Normal iron regulation is maintained by the HFE protein, which helps control how much iron is absorbed from your diet [1]. Having the G/G genotype means you do not carry the C282Y variant, which is responsible for the vast majority of hereditary hemochromatosis cases [2]. Your risk of developing iron overload is extremely low, and your body's baseline iron markers, such as ferritin and transferrin saturation, are expected to be in the typical range [3]. While you are protected from genetic iron overload, maintaining a balanced diet remains important for overall metabolic health. Additionally, this genotype is associated with typical levels of LDL cholesterol and typical liver enzyme activity [4].
Normal dietary iron absorption; Typical baseline ferritin levels; Extremely low risk of genetic iron overload.
Sample genotype: AA (Homozygous)
Carrying two copies of the C282Y mutation is the primary genetic cause of hereditary hemochromatosis, accounting for the vast majority of cases [1]. This mutation prevents the HFE protein from reaching the cell surface, disrupting the body's ability to limit iron absorption [2]. As a result, iron gradually accumulates in vital organs, which can lead to liver cirrhosis, diabetes, joint pain, and heart issues if left unmanaged [3]. However, not everyone with this genotype develops severe symptoms; clinical penetrance is incomplete and is lower in pre-menopausal women due to natural iron loss [4]. This genotype is also associated with higher hemoglobin levels, increased risk of osteoarthritis, and a higher likelihood of non-alcoholic fatty liver disease [6] [7].
Significantly increased dietary iron absorption; High risk of clinical iron overload; Elevated serum ferritin and transferrin saturation.
Sample genotype: GA (Heterozygous)
Having one copy of the C282Y mutation means you are a carrier of hereditary hemochromatosis [1]. Because this condition is recessive, carriers typically do not develop clinical iron overload or experience symptoms [2]. However, large-scale genetic studies show that carriers often have slightly higher serum iron, transferrin saturation, and ferritin levels than non-carriers [3]. While these levels usually remain within a safe range, they can occasionally become elevated if combined with other genetic variants or high dietary iron intake [4]. Additionally, carriers may be more sensitive to certain medications like erythropoietin if undergoing specific treatments [5]. Knowing your carrier status is highly valuable for understanding your family's genetic health and potential risks for future generations.
Carrier of the C282Y mutation; Slightly elevated baseline iron markers; Potential to pass the variant to offspring.
Variants with shared genetic architecture
rs1799945 · HFE Gene · Chr 6 · Iron Overload Risk
rs79220007 · HFE Gene · Chr 6 · Iron Overload Risk
rs1800730 · HFE Gene · Chr 6 · Iron Overload Risk
A novel MHC class I-like gene is mutated in patients with hereditary haemochromatosis.
Novel loci affecting iron homeostasis and their effects in individuals at risk for hemochromatosis.
Biological, clinical and population relevance of 95 loci for blood lipids.
Penetrance of 845G--> A (C282Y) HFE hereditary haemochromatosis mutation in the USA.
Genetic variants in HFE are associated with non-alcoholic fatty liver disease in lean individuals.
Content updated August 2026.
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