HFE rs28936415: What Your Genotype Means
The HFE rs28936415 variant, commonly known as H63D, is a genetic change in the HFE gene that influences how the body regulates iron. While it is frequently studied in the context of hereditary hemochromatosis, its clinical significance is often considered lower than other HFE variants.
What each genotype means
Typical iron metabolism
This genotype represents the most common form of the HFE gene, often referred to as the wild-type. Individuals with this profile do not carry the H63D variant and are not at an increased genetic risk for hereditary hemochromatosis associated with this specific mutation.
This is the most common genotype found in the vast majority of the global population.
H63D carrier
Carrying one copy of the H63D variant is generally considered to have no significant, predictable risk of developing iron overload. While some studies suggest a potential for slightly elevated iron markers in certain populations, it is not considered clinically significant on its own.
The H63D variant is carried by approximately 10-15% of individuals of European ancestry.
H63D homozygous
Individuals with two copies of the H63D variant may show increased serum transferrin saturation, but this genotype is not typically associated with the development of clinically significant iron overload. In the absence of other genetic factors, such as the C282Y mutation, the risk of disease remains very low.
This genotype is relatively uncommon, occurring in a small percentage of the population, primarily among those of European descent.
Understanding the HFE Gene and rs28936415
The HFE gene provides instructions for making a protein that plays a critical role in iron homeostasis. This protein interacts with the transferrin receptor to help regulate the amount of iron absorbed from the diet. The rs28936415 variant, also referred to as p.His63Asp or H63D, involves a specific change in the DNA sequence that results in an amino acid substitution in the HFE protein. This variant is located within the gene's coding region, and researchers have long investigated whether this alteration impairs the protein's ability to properly signal iron levels to the body. Unlike some other genetic variants that cause severe, early-onset disease, the functional impact of H63D on iron regulation is generally considered to be less pronounced, leading to ongoing scientific discussion regarding its exact role in clinical iron overload.
Research and Clinical Associations
The H63D variant is most famously discussed in relation to hereditary hemochromatosis, a condition characterized by excessive iron accumulation in the body. However, the evidence linking H63D to clinical disease is complex and often described as having low penetrance. While homozygosity for the C282Y variant is the primary driver of classic hereditary hemochromatosis, the role of H63D is more nuanced. Some individuals who are compound heterozygotes—carrying one copy of C282Y and one copy of H63D—may have an increased risk of iron overload, but many individuals with the H63D variant never develop clinical symptoms. Recent literature has cautioned against over-interpreting the presence of H63D, noting that it is common in the general population and often does not lead to significant iron-related health issues. Consequently, some clinical guidelines suggest focusing diagnostic efforts on more high-risk variants.
Population Frequency
The H63D variant is relatively common, particularly in populations of European descent. Allele frequencies typically range between 10% and 15% in many European countries, though this can vary by region. For example, studies have observed frequencies around 12.5% in parts of Italy and Denmark, and slightly higher in France. The variant is also present, though generally at lower frequencies, in other global populations, including those in Southeast Asia. Because the variant is so widespread, it is frequently identified in genetic screening panels. Its high prevalence in healthy individuals underscores the fact that carrying the variant is not synonymous with having a disease, and most people who carry one or even two copies of the H63D allele will not experience clinically significant iron overload.
Navigating Genetic Information
If you have received information about your HFE genotype, it is important to interpret it within the context of your overall health. Genetic testing results for H63D should not be used to self-diagnose or predict future health outcomes without professional guidance. Because the clinical significance of this variant is often limited or uncertain, it is not a reliable standalone predictor of iron-related disorders. If you are concerned about your iron levels or have a family history of hemochromatosis, the most appropriate step is to consult with a healthcare provider or a genetic counselor. They can order appropriate blood tests, such as serum ferritin or transferrin saturation, which provide a direct measure of your body's iron status. Never make changes to your diet or supplement regimen based on genetic data alone without first discussing these results with your clinician.
How common is this variant?
The H63D variant is common, with a minor allele frequency of approximately 10-15% across many European populations.
Frequently asked questions
Does having the H63D variant mean I have hemochromatosis?
No, having the H63D variant does not mean you have hemochromatosis. The variant is common in the general population, and most people who carry it do not develop iron overload or related symptoms.
What is the difference between C282Y and H63D?
C282Y is a variant more strongly associated with the development of hereditary hemochromatosis. H63D is a different, more common variant that is generally considered to have a much lower impact on iron regulation.
Should I get tested for HFE variants?
Genetic testing for HFE variants is typically recommended only if a doctor suspects iron overload based on blood test results or family history. You should discuss the necessity of such testing with your healthcare provider.
Can I prevent iron overload if I have the H63D variant?
If you are concerned about iron levels, the best approach is to monitor your iron status through blood tests ordered by a physician. Lifestyle changes should only be implemented under the guidance of a medical professional.
Sources & further reading
Educational information only, last refreshed 9/20/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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The Ser65Cys missense polymorphism in HFE linked to mild systemic iron regulation changes and downstream impacts on hypogonadotropic reproductive function.
The C282Y missense variant in HFE is the primary genetic cause of hereditary hemochromatosis, leading to iron overload.
Common HFE missense variant H63D associated with hereditary hemochromatosis and mild iron overload risk.
Coding variant (p.Val162Met) in the homeostatic iron regulator gene studied alongside classical hemochromatosis variants.
Known as HFE S65C (c.193A>T), this missense variant is associated with mild variations in transferrin saturation and iron accumulation, often evaluated alongside C282Y and H63D.
The H63D missense variant in HFE, associated with mild iron overload phenotypes.