MCM8 rs16991616: What Your Genotype Means
The rs16991616 variant is a genetic change located within the MCM8 gene. It has been identified through large-scale genome-wide association studies as being linked to variations in the age at which women reach natural menopause.
What each genotype means
Typical reproductive timing
This genotype represents the most common form of the MCM8 variant observed in the general population. Research indicates that individuals with this genetic profile do not carry the specific allele associated with an increased risk of earlier natural menopause. This finding is based on statistical associations in large-scale studies and does not predict individual reproductive health outcomes.
Carried by the majority of individuals in most populations, with a frequency of approximately 85% in European ancestries.
Slightly earlier menopause association
This genotype includes one copy of the variant allele linked to variations in the timing of natural menopause. Large-scale meta-analyses have associated this specific allele with a statistically significant trend toward an earlier age at natural menopause. This association is part of a complex genetic architecture and should not be interpreted as a diagnostic indicator of reproductive lifespan.
Carried by roughly 1 in 7 people of European ancestry; frequency varies significantly across other global populations.
Increased early menopause association
This genotype includes two copies of the variant allele that has been robustly linked to a statistically earlier age at natural menopause in large-scale genetic studies. While this variant is associated with reproductive timing, it is only one of many genetic and environmental factors that influence ovarian function. These findings are based on population-level data and do not determine individual fertility or the exact timing of menopause.
This genotype is the least common of the three, found in approximately 1% of individuals of European ancestry.
Understanding the rs16991616 Variant
The rs16991616 variant is a single-nucleotide polymorphism (SNP) located within the MCM8 gene on chromosome 20. In genetics, a SNP represents a variation at a single position in the DNA sequence among individuals. This specific variant is categorized as a missense variant, meaning the change in the DNA sequence results in a different amino acid being incorporated into the protein produced by the gene. Researchers study these variants to understand how subtle differences in our genetic code contribute to biological diversity and health outcomes. Because rs16991616 is located in a region associated with reproductive aging, it has become a subject of interest in studies examining the genetic architecture of the human reproductive lifespan.
The Role of the MCM8 Gene
The MCM8 gene encodes a protein that is part of the minichromosome maintenance complex. This complex plays a critical role in DNA replication and the repair of DNA damage. Maintaining the integrity of DNA is essential for the health and function of many cell types, including those in the ovaries. Research has shown that the MCM8 protein is involved in the DNA damage repair (DDR) pathway, which is vital for the maintenance of the ovarian reserve—the pool of follicles that determines reproductive lifespan. When these repair mechanisms are impaired, it can affect the stability of germ cells. Studies in animal models have demonstrated that the absence of functional MCM8 can lead to sterility, highlighting the gene's importance in normal gonadal development and function.
Research Associations and Evidence Strength
The association between rs16991616 and the age at natural menopause has been observed in large-scale meta-analyses of genome-wide association studies (GWAS). These studies compare the DNA of thousands of individuals to identify statistical links between specific variants and traits. While the link between this SNP and the timing of menopause is statistically robust in these population-level studies, the evidence strength for its individual clinical impact remains limited. It is important to distinguish between a statistical association found in a large group and a direct cause-and-effect relationship for an individual. Furthermore, while rare, highly disruptive mutations in the MCM8 gene have been linked to primary ovarian insufficiency, the common rs16991616 variant is generally considered a contributor to natural variation rather than a direct cause of clinical disease.
Population Frequency
The rs16991616 variant is found across various human populations, with a minor allele frequency (MAF) of approximately 0.08 in European ancestries. This means that the variant is relatively common, appearing in a significant portion of the population. Frequency can vary between different ancestral groups, and researchers often use large databases like gnomAD to track these differences. Understanding the frequency of a variant helps scientists determine whether a genetic change is a rare, potentially harmful mutation or a common variation that contributes to the normal range of human traits.
Interpreting Your Genetic Information
Genetic information regarding variants like rs16991616 provides insight into the complex factors that influence reproductive health, but it should not be used for medical diagnosis. The timing of menopause is influenced by a wide array of factors, including genetics, lifestyle, and environmental exposures. Having a specific genotype does not guarantee a particular outcome, nor does it provide a precise prediction of when an individual will reach menopause. If you have concerns about your reproductive health, fertility, or the timing of menopause, the most appropriate step is to consult with a healthcare professional, such as a gynecologist or a reproductive endocrinologist. They can provide personalized guidance based on your medical history and clinical symptoms, which are far more informative than a single genetic variant.
How common is this variant?
The rs16991616 variant has a minor allele frequency of approximately 0.08 in European ancestries, making it a relatively common genetic variation.
Frequently asked questions
Does the rs16991616 variant cause early menopause?
No, this variant is associated with natural variation in the timing of menopause, not a direct cause of early menopause. Most people with this variant will experience menopause within the normal age range.
Can I use this SNP to predict my menopause age?
No, current scientific evidence does not support using this SNP to accurately predict the age of menopause for an individual. Menopause timing is influenced by many genetic and environmental factors.
Is MCM8 related to fertility issues?
Rare, severe mutations in the MCM8 gene have been linked to primary ovarian insufficiency. However, the common rs16991616 variant is generally associated with normal reproductive aging rather than clinical infertility.
Should I get tested for this variant?
There is no clinical utility in testing for this specific variant for the general public. If you have concerns about your reproductive health, you should speak with a doctor rather than relying on genetic testing for common variants.
Sources & further reading
Educational information only, last refreshed 9/25/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Intergenic/regulatory variant near MCM8 strongly linked to the timing of natural menopause and primary ovarian insufficiency risk.
Missense variant in MCM8 associated with DNA repair integrity in germ cells and susceptibility to accelerated ovarian aging.
A missense variant in MCM8 associated with DNA helicase activity, meiotic function, and altered timing of menopause.
Missense variant (p.Glu336Lys, c.1006G>A) in the MCM8 helicase gene significantly associated with accelerated oocyte depletion and earlier age at natural menopause.
This variant in the MCM8 gene shows suggestive association with age at natural menopause in European American women.