Y-Chromosome Variant rs3991109: Understanding Ancestral Lineages
The variant rs3991109 is a single nucleotide polymorphism located on the human Y chromosome. It serves as a genetic marker used by researchers to distinguish specific paternal lineages within Haplogroup E1b1a1a1a1c1a.
What each genotype means
Haplogroup E lineage marker
This genotype is a specific marker on the Y chromosome used to identify paternal lineages within Haplogroup E, specifically E1b1a1a1a1c1a. Because the Y chromosome is passed from father to son, this variant serves as a genealogical tool rather than a predictor of health or disease traits.
This genotype is part of a set of variants with a global minor allele frequency of approximately 0.08736, though specific frequencies vary significantly by ancestral population.
Haplogroup E lineage marker
This genotype is a specific marker on the Y chromosome used to identify paternal lineages within Haplogroup E, specifically E1b1a1a1a1c1a. Because the Y chromosome is passed from father to son, this variant serves as a genealogical tool rather than a predictor of health or disease traits.
This genotype is part of a set of variants with a global minor allele frequency of approximately 0.08736, though specific frequencies vary significantly by ancestral population.
Haplogroup E lineage marker
This genotype is a specific marker on the Y chromosome used to identify paternal lineages within Haplogroup E, specifically E1b1a1a1a1c1a. Because the Y chromosome is passed from father to son, this variant serves as a genealogical tool rather than a predictor of health or disease traits.
This genotype is part of a set of variants with a global minor allele frequency of approximately 0.08736, though specific frequencies vary significantly by ancestral population.
What is rs3991109?
A single nucleotide polymorphism, or SNP, is a variation at a single position in a DNA sequence. The variant rs3991109 is located on the Y chromosome, which is passed exclusively from fathers to their sons. Because the Y chromosome does not undergo recombination in the same way as other chromosomes, these markers remain relatively stable over many generations. This stability makes Y-SNPs like rs3991109 highly valuable for tracing paternal ancestry and defining specific branches of the human family tree. By identifying the presence or absence of this specific nucleotide change, geneticists can categorize individuals into distinct haplogroups, which are groups of people who share a common paternal ancestor.
The Role of Y-Chromosome Markers
The Y chromosome is unique in the human genome because it is inherited in a direct patrilineal line. While most of our DNA is a mix of genetic material from both parents, the Y chromosome is passed down from father to son largely unchanged, except for occasional mutations. These mutations, such as rs3991109, act as historical signposts. When a mutation occurs in a man, it is passed on to all his male descendants. Over thousands of years, these accumulated mutations create a branching structure known as a phylogenetic tree. Researchers use these markers to map human migration patterns and understand the deep ancestral history of populations across the globe.
Research and Evidence
The evidence regarding rs3991109 is primarily focused on its utility in population genetics and genealogical research. It is classified as an ancestral marker, meaning its primary scientific value lies in its ability to help define the structure of Y-DNA haplogroups. Specifically, it is associated with the classification of Haplogroup E1b1a1a1a1c1a. Currently, there is no evidence in major clinical databases suggesting that this variant is associated with any specific health conditions or medical traits. Its significance is strictly limited to the field of genetic anthropology and paternal lineage tracing. As with many Y-chromosomal markers, the research is descriptive rather than functional, serving as a tool for mapping human diversity rather than predicting clinical outcomes.
Population Frequency
The frequency of Y-chromosome variants can vary significantly depending on the geographic and ethnic background of the population being studied. For rs3991109, the Global Minor Allele Frequency (GMAF) is reported at approximately 0.08736. This frequency reflects the proportion of individuals in the studied populations who carry the derived allele. Because Y-SNPs are tied to specific paternal lineages, their distribution is not uniform across the world; instead, they are often concentrated in specific regions where the ancestral lineage is most prevalent. Understanding these frequencies helps researchers refine the branches of the Y-chromosome tree and provides context for how specific lineages have expanded or migrated over time.
Interpreting Your Genetic Information
Information regarding Y-chromosome variants like rs3991109 is intended for educational and genealogical purposes. If you have received results indicating your status for this variant, it is important to understand that this information relates to your paternal ancestry and does not provide medical or health-related insights. You cannot use this information to diagnose, treat, or predict any health conditions. Genetic genealogy can be a fascinating way to explore your family history and understand your connection to broader human migration patterns. If you have questions about your genetic results or how they relate to your family history, consider consulting with a professional genetic counselor who can help you interpret the data within the appropriate context.
How common is this variant?
The variant has a Global Minor Allele Frequency (GMAF) of 0.08736, reflecting its distribution within specific paternal lineages.
Frequently asked questions
Is rs3991109 linked to any diseases?
No, rs3991109 is a Y-chromosomal marker used for ancestral tracing. There is no current scientific evidence linking this variant to any medical conditions or health traits.
Can women have the rs3991109 variant?
No, because rs3991109 is located on the Y chromosome, it is only found in individuals who carry a Y chromosome, which is typically biological males.
What does it mean if I have the A allele?
Having the A allele indicates that you belong to a specific branch of the Y-chromosome tree within Haplogroup E. It is a marker of your paternal ancestral lineage.
How is this variant used in genealogy?
Geneticists and genealogists use this SNP to identify and distinguish specific paternal lineages. It helps individuals determine their placement on the Y-DNA haplogroup tree.
Sources & further reading
Educational information only, last refreshed 9/26/2026. Not medical advice — these associations describe population statistics, not individual predictions.
Curious what your genotype is for rs3991109?
Upload a raw DNA file from 23andMe, AncestryDNA, MyHeritage, or FamilyTreeDNA and see this variant — plus thousands more — interpreted in your full report.
Get my report — $29