OCA2 rs1800408: Understanding Your Genetic Pigmentation Trait
The rs1800408 variant is a specific genetic change located within the OCA2 gene. It is statistically associated with variations in human pigmentation, including differences in eye and hair color.
What each genotype means
Typical melanin synthesis
This genotype represents the most common form of the OCA2 gene at this position. It is associated with standard levels of oculocutaneous melanin production, which contributes to typical eye and hair pigmentation patterns in many populations.
This is the most frequent genotype globally, carried by the vast majority of individuals across most ancestral groups.
Intermediate pigmentation influence
Carrying one copy of the T allele may result in a subtle shift in melanin synthesis compared to the CC genotype. Research suggests this variant is associated with variations in eye and hair color, though the specific phenotypic outcome is influenced by a complex interplay of other genetic and environmental factors.
This genotype is found in approximately 1 in 4 to 1 in 5 people in Northern and Western European populations.
Associated with lighter pigmentation
Individuals with this genotype carry two copies of the T allele, which is statistically associated with a higher likelihood of lighter eye and hair color traits. This variant, known as Arg305Trp, influences the function of the OCA2 protein in melanin synthesis, though it does not determine pigmentation in isolation.
This genotype is less common, appearing in roughly 1 to 2 percent of individuals in Northern and Western European populations.
What is the rs1800408 Variant?
The rs1800408 variant is a single nucleotide polymorphism (SNP) located within the OCA2 gene on chromosome 15. In genetics, a SNP represents a variation at a single position in the DNA sequence. This specific variant is often referred to as Arg305Trp, which describes a missense change where the amino acid arginine is replaced by tryptophan in the resulting protein. Because this change occurs in the coding region of the gene, it has the potential to alter the structure or function of the protein produced by the cell. Researchers study such variants to understand how small differences in our genetic code contribute to the wide range of physical traits observed across human populations, particularly those related to pigmentation.
The Role of the OCA2 Gene
The OCA2 gene provides the instructions for creating the P protein, which is essential for the function of melanocytes. Melanocytes are specialized cells responsible for producing melanin, the primary pigment that determines the color of our skin, hair, and eyes. The P protein acts as a transporter within these cells, helping to regulate the environment necessary for melanin synthesis. When the OCA2 gene functions normally, it supports the production of sufficient pigment. However, variations in this gene can lead to reduced P protein activity, which is linked to lighter pigmentation phenotypes. While the OCA2 gene is central to normal pigment variation, it is also the site of mutations that can cause oculocutaneous albinism type 2, a condition characterized by significantly reduced melanin production.
Research and Evidence Strength
Scientific research has identified rs1800408 as being associated with human pigmentation traits, specifically influencing eye and hair color. The evidence for this association is considered limited in terms of its individual predictive power, as pigmentation is a complex polygenic trait influenced by many different genes and environmental factors. While studies have observed statistical correlations between this variant and lighter pigmentation in certain groups, it is not a sole determinant of eye or hair color. Most research in this area highlights that pigmentation is the result of the combined effects of multiple variants across the genome, including those in the HERC2/OCA2 locus. Because the evidence is limited and the trait is complex, this variant should be viewed as one small piece of a much larger genetic puzzle rather than a definitive predictor of physical appearance.
Population Frequency
The frequency of the rs1800408 variant varies significantly across different ancestral groups. In Northern and Western European populations, the T allele is observed at a frequency of approximately 0.12. This means that the variant is relatively common in these populations, though it is not the majority allele. Because allele frequencies are highly dependent on ancestry, these statistics may not apply to individuals from other global populations. Understanding these frequency differences is a key part of population genetics, as it helps researchers determine how certain traits have been distributed and maintained throughout human history. It is important to remember that these frequencies are population-level averages and do not predict the specific genotype of any single individual.
Interpreting Your Genetic Information
Information about variants like rs1800408 is primarily educational and intended to provide insight into the genetic basis of human diversity. It is important to understand that this information cannot be used to diagnose medical conditions or predict specific physical traits with certainty. Because pigmentation is influenced by a wide array of genetic and environmental factors, knowing your genotype for a single SNP provides only a very narrow view of your overall genetic makeup. If you have questions about your health, skin, or eye conditions, you should consult with a qualified healthcare professional or a genetic counselor. They can provide context based on your full medical history and clinical presentation, which is far more informative than looking at a single genetic variant in isolation.
How common is this variant?
The T allele frequency for rs1800408 is approximately 0.12 in Northern and Western European populations.
Frequently asked questions
Can this SNP predict my exact eye color?
No, this SNP cannot predict your exact eye color. Eye color is a complex trait influenced by many different genes and environmental factors, and this variant is only one of many contributors.
Is rs1800408 associated with any diseases?
While the OCA2 gene is associated with oculocutaneous albinism, rs1800408 is primarily studied as a marker for normal variation in pigmentation traits rather than as a cause of disease.
Should I be concerned if I have the T allele?
No, there is no reason for concern. The T allele is a common genetic variation associated with normal human diversity in pigmentation and is not considered a medical risk factor.
Where can I learn more about my genetic traits?
You can explore resources like MedlinePlus Genetics or the GWAS Catalog to learn more about how genes influence human traits. For personal health concerns, always speak with a healthcare provider.
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 rs1800408?
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 — $29Related variants in OCA2
This missense variant (p.Ala486Thr) in the OCA2 gene is associated with human pigmentation traits, including eye and skin color variation.
This variant is located within the OCA2 gene, which encodes the P protein essential for melanin production and is a key locus for human pigmentation variation.
Missense variant Arg419Gln strongly linked to intermediate eye color, blue/green iris phenotypes, and lighter pigmentation.
Pigmentation-modifying SNP modulating blue versus brown eye color penetrance and melanin deposition.
Functional non-synonymous variant (Arg419Gln) in OCA2 linked with ancestral pigmentation divergence and lighter eye/skin color.
Common missense variation (Arg305Trp) in OCA2 associated with eye color gradation and lighter skin pigmentation in European populations.