HSD17B1 rs4646994: Understanding Your Genetic Variant
The rs4646994 variant is a common genetic change located within the HSD17B1 gene. It is associated with variations in the activity of the 17-beta-hydroxysteroid dehydrogenase type 1 enzyme and baseline circulating steroid hormone levels.
What each genotype means
Typical HSD17B1 activity
This genotype represents the most common form of the HSD17B1 gene in many populations. Research suggests this version of the enzyme is involved in the conversion of estrone to estradiol, and individuals with this profile are considered to have a baseline level of enzyme activity. This is a common genetic variation and is not considered a diagnostic indicator of disease.
Carried by approximately 30% to 35% of individuals of European ancestry.
Varied HSD17B1 activity
Carrying one copy of the G allele may influence the efficiency of the 17-beta-hydroxysteroid dehydrogenase type 1 enzyme. Studies have investigated whether this missense change (p.Ser312Gly) alters circulating steroid hormone balance, though the clinical significance remains limited and research findings are mixed. Please discuss any concerns regarding hormone levels or reproductive health with your clinician.
Carried by approximately 45% to 50% of individuals of European ancestry.
Altered HSD17B1 activity
This genotype results in the expression of the variant form of the HSD17B1 enzyme. While this variant is associated with differences in baseline steroid hormone balance in some research studies, the evidence linking it to specific clinical outcomes is limited. It is important to remember that many factors influence hormone levels; consult with a healthcare provider to interpret these results in the context of your overall health.
Carried by approximately 15% to 20% of individuals of European ancestry.
What is rs4646994?
The rs4646994 variant is a single nucleotide polymorphism (SNP) located in the HSD17B1 gene. In genetics, a SNP represents a variation at a single position in the DNA sequence among individuals. This specific variant is classified as a missense mutation, meaning the change in the DNA sequence results in a different amino acid being incorporated into the protein structure. Specifically, this change leads to a substitution of serine for glycine at position 312 (p.Ser312Gly) in the resulting protein. Because this protein is an enzyme responsible for critical chemical reactions in the body, such structural changes can potentially influence how efficiently the enzyme functions. Researchers track these variants to understand how subtle differences in our genetic code contribute to the diversity of human biological traits, including how our bodies process hormones.
The Role of the HSD17B1 Gene
The HSD17B1 gene provides instructions for making an enzyme called 17-beta-hydroxysteroid dehydrogenase type 1. This enzyme plays a central role in the body's endocrine system by facilitating the conversion of steroid hormones. Specifically, it is primarily involved in the reduction of estrogens and androgens, which are essential for various physiological processes, including reproductive health and development. By acting on the C17 hydroxy or keto group of these hormones, the enzyme helps regulate the balance of active versus inactive forms of steroids in tissues. Because this enzyme is highly active in specific tissues like the ovaries and the placenta, its function is closely tied to the regulation of estrogen levels. Understanding the function of this gene is important for researchers studying how hormonal pathways are maintained and how variations in these pathways might influence individual differences in hormone-related traits.
Research and Evidence
Current research into rs4646994 focuses on its association with baseline steroid hormone levels. The evidence for this variant is considered limited, meaning that while statistical associations have been observed in various studies, the clinical implications are not fully established. Scientists have investigated whether the p.Ser312Gly change alters the catalytic activity of the 17-beta-hydroxysteroid dehydrogenase type 1 enzyme. Some studies suggest that this variant may influence the circulating levels of certain hormones, but these effects are often subtle and can be influenced by many other genetic and environmental factors. Because the evidence is currently limited, it is important to view these findings as part of ongoing scientific exploration rather than definitive medical markers. The scientific community continues to study this variant to better understand its role in the complex network of human hormonal regulation and its potential contribution to various physiological traits.
What This Information Means for You
It is important to understand that having a particular genotype for rs4646994 does not constitute a medical diagnosis or a prediction of health outcomes. Genetic variants like this are common and are part of the natural variation found within the human population. Because the evidence linking this variant to specific health traits is limited, it is not currently used in clinical settings to guide medical decisions or treatments. If you have questions about your hormone levels or concerns about your health, the most appropriate step is to consult with a qualified healthcare professional. They can provide personalized guidance based on your medical history, physical examinations, and validated clinical tests. Genetic information should always be interpreted in the context of a comprehensive health assessment, and you should never make changes to your health regimen based solely on information about a single genetic variant.
How common is this variant?
The rs4646994 variant is common, with a minor allele frequency typically ranging between 0.40 and 0.48 in populations of European ancestry.
Frequently asked questions
Is rs4646994 associated with a specific disease?
Current research does not classify rs4646994 as a diagnostic marker for any specific disease. While it is studied for its potential influence on hormone levels, the evidence linking it to clinical conditions remains limited and inconclusive.
Can I use this SNP to predict my hormone levels?
No, this SNP cannot be used to accurately predict your hormone levels. Hormone levels are influenced by a complex interplay of many genes, lifestyle factors, and environmental influences, making a single SNP insufficient for such predictions.
Should I be concerned if I have the G allele?
There is no reason for concern regarding this variant. It is a common genetic variation found in a large portion of the population and is considered a normal part of human genetic diversity.
Where can I find more information about HSD17B1?
You can find reliable information about the HSD17B1 gene through resources like MedlinePlus Genetics or the NCBI Gene database. These platforms provide comprehensive summaries of gene functions and their roles in human biology.
Sources & further reading
Educational information only, last refreshed 10/14/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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