PRORY rs13303755: Understanding Your Y-DNA Haplogroup Marker
The rs13303755 variant is a specific genetic marker located on the human Y chromosome. It is primarily used by researchers and genealogists to define and distinguish branches within the R1a1b2a1a1 Y-DNA haplogroup.
What each genotype means
Ancestral Y-DNA lineage
This genotype represents the ancestral state for this marker, which is associated with the R1a1b2a1a1 Y-DNA haplogroup. It serves as a baseline marker and does not indicate the presence of the specific derived lineage associated with the T allele.
This genotype is found in individuals who do not carry the specific mutation defining the R1a1b2a1a1d sub-lineage.
Heterozygous Y-DNA marker
Because this variant is located on the Y chromosome, which is typically present as a single copy in males, a heterozygous result is generally not expected in standard biological samples. If observed, this may indicate a technical artifact or a complex structural variation that should be interpreted with caution.
This genotype is extremely rare or non-existent in typical male populations due to the hemizygous nature of the Y chromosome.
Derived Y-DNA lineage
This genotype indicates the presence of the derived allele, which is a recognized marker used to define the R1a1b2a1a1d Y-DNA haplogroup. This is a genealogical marker used for tracing paternal ancestry and does not have known clinical or health-related implications.
This genotype is specific to individuals belonging to the R1a1b2a1a1d lineage, which represents a small subset of the broader R1a1b2a1a1 haplogroup.
What is rs13303755?
The rs13303755 variant is a single nucleotide polymorphism (SNP) located on the Y chromosome at position 21,450,311 (GRCh38). Because it resides on the Y chromosome, it is passed exclusively from father to son, making it a powerful tool for tracing paternal ancestry. In the context of genetic genealogy, this SNP is also known by the alternative names L48 and S162. It serves as a diagnostic marker that helps scientists and genealogists categorize male lineages into specific branches of the human Y-DNA tree. By identifying whether an individual carries the ancestral or derived allele at this position, researchers can determine if a person belongs to the R1a1b2a1a1d haplogroup, a specific sub-clade of the broader R1a haplogroup family.
The Role of the PRORY Gene
The rs13303755 variant is associated with the PRORY gene, which stands for 'Proline Rich Y-Linked'. PRORY is classified as a long non-coding RNA (lncRNA) gene. Unlike protein-coding genes that provide instructions for building specific proteins, lncRNAs are involved in various regulatory processes within the cell. While the PRORY gene is located on the Y chromosome, the primary significance of the rs13303755 marker in current literature is its utility as a phylogenetic tool rather than its functional impact on health or disease. There is currently no evidence in major clinical databases suggesting that this specific variant influences physical traits, disease risk, or medical outcomes. Its primary value remains in the field of population genetics and the mapping of human migration patterns through paternal lineages.
Research and Evidence Strength
The evidence linking rs13303755 to the R1a1b2a1a1d haplogroup is considered robust within the field of genetic genealogy and population genetics. This variant is a recognized marker used to define branches within the Y-DNA tree, as documented in established phylogenetic builds such as those maintained by ISOGG. However, it is important to note that this is a trait-based marker for ancestry, not a clinical marker. It does not appear in major clinical databases like ClinVar as a variant associated with medical conditions or drug responses. Because the Y chromosome does not undergo recombination in the same way as other chromosomes, this marker remains stable across generations, providing a reliable, albeit narrow, window into paternal history. It is not used for medical diagnostics or risk assessment.
Population Frequency and Distribution
The frequency of rs13303755 is highly specific to individuals who carry the R1a1b2a1a1d Y-DNA haplogroup. Because it is a lineage-defining marker, it is not distributed randomly across the global population. Instead, its presence is restricted to the specific paternal descendants of the branch where this mutation originally occurred. Consequently, you will not find this variant in the general population at high frequencies; it is essentially absent in any lineage that does not descend from the R1a1b2a1a1d clade. For those interested in their own genetic makeup, this marker is often included in commercial ancestry testing panels that analyze Y-DNA. If you have received results regarding this marker, it is a reflection of your deep paternal ancestry rather than a reflection of your current health status.
What This Information Means for You
Understanding your status for rs13303755 provides insight into your paternal heritage. It can help you connect with others who share a common male ancestor and place your lineage on the global Y-DNA map. However, it is crucial to understand that this information is strictly for genealogical and educational purposes. It cannot be used to predict health outcomes, diagnose medical conditions, or inform clinical decisions. Because this variant is not linked to any known medical traits, there is no 'favorable' or 'unfavorable' result. If you have questions about your genetic ancestry, you may wish to consult with a professional genetic genealogist. If you have concerns about your health or genetic risk factors, please consult with a qualified healthcare provider or a genetic counselor, as ancestry markers are not relevant to clinical medical care.
How common is this variant?
This variant is highly specific to the R1a1b2a1a1d Y-DNA haplogroup and is not found in the general population outside of these specific paternal lineages.
Frequently asked questions
Is rs13303755 associated with any diseases?
No. There is no evidence in current scientific literature or clinical databases linking this variant to any medical conditions or health risks.
Can I use this marker to determine my health?
No. This marker is used exclusively for tracing paternal ancestry and has no clinical utility for health assessment or medical diagnosis.
What does it mean if I have the T allele?
Carrying the T allele indicates that you belong to the R1a1b2a1a1d Y-DNA haplogroup, which is a specific branch of paternal ancestry.
Why is this marker on the Y chromosome?
The Y chromosome is passed from father to son, which allows researchers to use markers like rs13303755 to track paternal lineages over thousands of years.
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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