SLC45A2 rs1158810: What Your Genotype Means
The rs1158810 variant is a single nucleotide polymorphism located within the SLC45A2 gene. It is primarily recognized for its association with human pigmentation traits, including variations in skin, hair, and eye color.
What each genotype means
Typical baseline pigmentation likelihood
You carry two copies of the C allele for this synonymous variant in the SLC45A2 gene. While this change does not alter the protein sequence directly, it commonly tags ancestral haplotypes that are statistically linked to darker or baseline pigmentation traits, such as darker hair, eye, or skin tones. Because overall coloration is influenced by many genes and environmental factors, this variant alone does not determine your exact physical appearance.
Carried by approximately 20% to 30% of individuals of European ancestry, and at much higher rates in African and East Asian populations where the C allele predominates.
Intermediate pigmentation association
You carry one C allele and one T allele for this SLC45A2 marker. Because this silent genetic variant is in high linkage disequilibrium with functional pigmentation alleles in certain ancestries, having one T allele is modestly correlated with intermediate or lighter pigmentation tendencies. Evidence remains limited and ancestry-dependent, meaning this genotype does not reliably predict your hair, eye, or skin shade on its own.
Carried by roughly 45% to 50% of individuals of European descent, while being relatively uncommon in East Asian and African populations.
Lighter pigmentation association
You carry two copies of the T allele at this SLC45A2 locus. In research cohorts, the homozygous TT genotype frequently tracks alongside functional missense variants like p.Phe374Leu, which are statistically associated with lighter skin, hair, or eye pigmentation in European-derived populations. However, the direct functional impact of this specific synonymous variant is limited, and multiple other genetic and environmental factors shape pigmentation.
Found in approximately 20% to 25% of individuals of European ancestry, but rarely observed in populations of African or East Asian descent.
Understanding the rs1158810 Variant
The rs1158810 variant is a specific genetic marker, or single nucleotide polymorphism (SNP), situated within the SLC45A2 gene. In genetics, a SNP represents a variation at a single position in the DNA sequence among individuals. This particular variant is classified as a synonymous change, meaning it does not alter the amino acid sequence of the protein produced by the gene. However, rs1158810 is frequently studied because it exists in high linkage disequilibrium with other functional variants in the same region. Linkage disequilibrium describes a situation where specific alleles at different locations on a chromosome are inherited together more often than would be expected by chance. Consequently, while rs1158810 itself may not be the direct cause of a biological change, it serves as a reliable proxy for identifying nearby genetic variations that do influence physical traits.
The Role of the SLC45A2 Gene
The SLC45A2 gene, also known as MATP, provides instructions for creating a protein found in specialized cells called melanocytes. These cells are responsible for producing melanin, the pigment that determines the color of human skin, hair, and eyes. While the exact mechanism of the SLC45A2 protein is still being researched, it is believed to play a critical role in the function of melanosomes, which are the internal structures where melanin synthesis occurs. By regulating the environment within these structures, such as controlling pH levels, the protein facilitates the production and transport of pigment. Mutations that significantly disrupt the function of this gene can lead to oculocutaneous albinism type 4 (OCA4), a condition characterized by reduced pigmentation. In the general population, however, common variations in this gene contribute to the wide spectrum of normal human pigmentation diversity observed across different global ancestries.
Research and Evidence Strength
Scientific research has consistently identified the SLC45A2 region as a major contributor to pigmentation differences in humans. Studies, including genome-wide association studies (GWAS), have linked variants in this gene to variations in skin, hair, and eye color, particularly in European populations. The evidence for the involvement of the SLC45A2 gene in pigmentation is strong; however, the evidence specifically for rs1158810 is considered limited in terms of it being a direct functional driver. Because rs1158810 is a synonymous variant, its observed associations with physical traits are largely attributed to its proximity to other functional alleles that are under strong selective pressure. Researchers use this SNP as a marker to track these linked functional variants, which have been shown to influence how melanin is produced and distributed. As with many complex traits, pigmentation is polygenic, meaning it is influenced by the combined effects of many different genes and environmental factors.
Population Frequency and Distribution
The rs1158810 variant is notably common in European populations. Genetic studies have shown that the frequency of variants in the SLC45A2 gene often follows a latitudinal cline, reflecting historical patterns of human migration and adaptation to varying levels of ultraviolet radiation. In many European groups, the alleles associated with lighter pigmentation have reached high frequencies due to positive selection over thousands of years. Conversely, the distribution of these variants differs significantly in other global populations, such as those in East Asia or Africa, where different genetic markers often play a more prominent role in determining pigmentation. Understanding these frequency differences is a key area of study in human evolutionary genetics, as it helps scientists map how populations adapted to different environments throughout history. The prevalence of this SNP makes it a frequent subject in studies investigating the genetic architecture of human appearance.
Interpreting Your Genetic Information
It is important to understand that genetic variants like rs1158810 provide only a small piece of the puzzle regarding human traits. While this SNP is associated with pigmentation, it does not determine an individual's appearance in isolation. Many other genes, as well as environmental factors like sun exposure, interact to produce the final phenotype. Consumers should view this information as educational rather than diagnostic. This variant is not used for medical screening, and it does not provide information about health risks or disease susceptibility. If you are interested in learning more about your own genetic makeup, it is best to consult with a qualified genetic counselor or healthcare professional who can help interpret results in the context of your overall health and family history. Always approach direct-to-consumer genetic reports with the understanding that they represent statistical associations rather than definitive biological predictions.
How common is this variant?
The rs1158810 variant is common in European populations, with allele frequencies varying significantly across different global ancestries due to historical selective pressures.
Frequently asked questions
What does the SLC45A2 gene do?
The SLC45A2 gene provides instructions for a protein that helps regulate the production of melanin in melanocytes. Melanin is the pigment that gives color to our skin, hair, and eyes.
Is rs1158810 a cause of albinism?
No, rs1158810 is a common variant associated with normal variation in pigmentation. Oculocutaneous albinism type 4 (OCA4) is caused by specific, rare mutations that severely disrupt the function of the SLC45A2 protein.
Can I use this SNP to predict my eye color?
While this SNP is associated with pigmentation, it is not a reliable predictor of eye color on its own. Pigmentation is a complex trait influenced by many different genes and environmental factors.
Why is this variant common in Europe?
The high frequency of certain SLC45A2 variants in Europe is thought to be the result of positive selection over thousands of years. This likely occurred as human populations adapted to environments with lower levels of ultraviolet radiation.
Sources & further reading
Educational information only, last refreshed 10/27/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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This missense variant (p.Phe374Leu) is a major determinant of human skin, hair, and eye pigmentation, showing strong evidence of selection in European populations.
Synonymous marker in the SLC45A2 locus associated with skin reflectance, tanning response, and freckling phenotypes.
This missense variant (p.Phe374Leu) is a key ancestry-informative marker and a classic signature of recent positive selection, strongly associated with skin pigmentation and melanoma risk.
This variant (p.Phe374Leu) is strongly associated with lighter skin, hair, and eye pigmentation, as well as an increased sensitivity to UV-induced skin damage.
The p.Phe374Leu variant in SLC45A2 is a major determinant of human pigmentation variation, influencing skin, hair, and eye color across global populations.
Promoter-associated regulatory variant implicated in hair and skin pigmentation variation across human populations.