SLC39A8 rs13107325: Understanding the p.Ala391Thr Variant
The rs13107325 variant is a missense mutation in the SLC39A8 gene that results in an amino acid change from alanine to threonine at position 391. This variant is highly pleiotropic, meaning it is statistically associated with a wide range of human traits, including sleep duration, metabolic markers, and psychiatric conditions.
What each genotype means
Typical SLC39A8 profile
This genotype represents the most common version of the SLC39A8 gene, which encodes a protein involved in metal ion transport. Research indicates that individuals with this genotype do not carry the specific missense variant (p.Ala391Thr) associated with altered sleep patterns or increased risk for certain complex health conditions.
This is the most common genotype globally, found in the vast majority of individuals across all ancestral populations.
Associated with sleep traits
Carrying one copy of the T allele means you possess the p.Ala391Thr variant, which has been statistically linked to variations in sleep duration and daytime sleepiness in large-scale studies. While this variant is also being investigated for potential associations with other complex traits like schizophrenia or Crohn's disease, these associations are based on population-level data and do not predict individual health outcomes.
This genotype is carried by approximately 1 in 6 to 1 in 10 people of European ancestry, but is significantly rarer in East Asian and African populations.
Increased variant presence
Carrying two copies of the T allele results in the p.Ala391Thr variant in both copies of the SLC39A8 gene. Research suggests this genotype may have a more pronounced association with sleep-related traits and is a subject of ongoing study regarding its potential role in neurodevelopmental and inflammatory pathways. These findings reflect statistical trends in large populations and are not diagnostic of any specific condition.
This genotype is relatively uncommon, occurring in a small percentage of individuals of European ancestry and is very rare in most other global populations.
What is rs13107325?
The rs13107325 variant is a single nucleotide polymorphism (SNP) located within the SLC39A8 gene on chromosome 4. Specifically, it is a missense variant, which means the change in the DNA sequence alters the protein product by substituting one amino acid for another—in this case, replacing alanine with threonine at position 391 (p.Ala391Thr). Because this change occurs in the coding region of the gene, it has the potential to alter the function of the resulting protein. Researchers often study this variant because it is considered a 'pleiotropic' marker, meaning it shows statistical associations with many different, seemingly unrelated physical and behavioral traits across the human population.
The Role of the SLC39A8 Gene
The SLC39A8 gene encodes a protein known as ZIP8, which functions as a metal ion transporter. This protein is responsible for moving essential divalent metal ions, such as manganese, zinc, and iron, into cells. Because these metals are critical cofactors for many enzymes and biological processes, the ZIP8 transporter plays a fundamental role in cellular health. It is expressed in various tissues throughout the body, including the brain, where it is involved in maintaining metal homeostasis. Disruptions in how these metals are transported can influence diverse physiological systems, which helps explain why variations in this gene are linked to such a broad spectrum of health-related outcomes, ranging from immune system function to neurological development.
Research and Trait Associations
The rs13107325 variant has been identified in numerous genome-wide association studies (GWAS). It is most notably associated with metabolic traits, including body mass index (BMI), HDL-cholesterol levels, and blood pressure. Additionally, research has linked this variant to sleep-related phenotypes, such as sleep duration and daytime sleepiness, as well as an increased risk for schizophrenia and Crohn's disease. While these associations are statistically robust, it is important to note that the evidence strength varies by trait. The biological mechanisms connecting the p.Ala391Thr change to these specific outcomes are still being actively investigated. Current research, including studies using animal models, aims to determine whether the variant directly causes these conditions or if it acts as a marker for other underlying genetic or environmental factors.
Population Frequency
The distribution of the rs13107325 variant is highly dependent on ancestry. The T allele (the variant associated with the traits mentioned) is found primarily in European populations, with a frequency of approximately 7% to 10%. In contrast, this variant is rare or absent in East Asian and African populations. This specific distribution pattern has led some researchers to hypothesize that the variant may have been subject to recent natural selection in European populations, potentially providing an evolutionary advantage in certain environments, even if it is associated with increased risk for specific health conditions in modern contexts.
Interpreting Your Genetic Information
Genetic variants like rs13107325 provide insight into the complex architecture of human traits, but they do not function as diagnostic tools. A statistical association found in a large population study does not mean that an individual with a specific genotype will necessarily develop a particular condition or trait. Many factors, including other genes, lifestyle, and environment, contribute to health outcomes. If you have questions about your health, sleep patterns, or metabolic markers, it is essential to consult with a qualified healthcare professional. They can provide context based on your personal medical history and clinical testing, which are far more informative than any single genetic variant. Never use genetic information to make changes to your medical care or medication regimen without professional guidance.
How common is this variant?
The T allele is found in approximately 7-10% of European populations but is rare in East Asian and African populations.
Frequently asked questions
Is rs13107325 a diagnostic test for schizophrenia?
No. While rs13107325 is associated with an increased risk for schizophrenia in large-scale studies, it is not a diagnostic test. Many genetic and environmental factors contribute to the development of psychiatric conditions.
Does this variant mean I will have sleep problems?
Not necessarily. The variant is associated with sleep duration and daytime sleepiness in population-level data, but it does not guarantee that an individual will experience these traits. Sleep health is influenced by many lifestyle and environmental factors.
Can I change my SLC39A8 gene?
No, your genetic sequence is inherited and does not change. However, understanding your genetic predispositions can help you and your doctor make informed decisions about your lifestyle and health monitoring.
Why is this variant only found in Europeans?
Genetic variants often show different frequencies across populations due to historical migration, genetic drift, and natural selection. The rs13107325 variant appears to have become more common in European populations over time.
Sources & further reading
Educational information only, last refreshed 10/16/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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This variant is associated with manganese levels and risk of neurological and inflammatory conditions.
Missense variant (p.Ala391Thr) in SLC39A8 linked to differences in HDL cholesterol, body mass index, blood pressure, and risk of schizophrenia.
A pleiotropic missense variant (p.Ala391Thr) affecting cellular manganese and zinc transport, linked across GWAS to lipid profiles, blood pressure, and inflammatory bowel disease risk.