PAX8 rs1191685: What Your Genotype Means for Sleep Duration
The rs1191685 variant is a genetic marker located in an intergenic region near the PAX8 gene. Large-scale genome-wide association studies have identified this locus as being associated with variations in habitual sleep duration.
What each genotype means
Typical baseline sleep duration
You carry two copies of the common C allele for this PAX8-region variant. Large genome-wide association studies show this genotype is not linked to extended sleep duration, representing the standard genetic baseline for nightly sleep time in population studies. Because individual sleep duration is shaped by hundreds of genetic loci alongside lifestyle and environmental factors, this single variant accounts for only a minor fraction of overall sleep variation.
Carried by approximately 50% to 55% of individuals in European populations, and more common in many non-European ancestries.
Slightly increased sleep duration
You carry one copy of the T allele associated with subtle increases in sleep duration in European ancestry cohorts. Research indicates that each copy of this PAX8-linked allele corresponds to a modest statistical increase of roughly a few minutes of self-reported nightly sleep. This trait association does not diagnose a sleep disorder or guarantee longer sleep, as sleep patterns depend heavily on circadian rhythm genetics, overall health, and daily habits.
Carried by roughly 35% to 40% of people of European ancestry, with lower prevalence observed in East Asian and African ancestries.
Modestly increased sleep duration
You carry two copies of the T allele linked upstream of the PAX8 gene to longer habitual sleep duration. In European meta-analyses, individuals with this genotype average several minutes more sleep per night compared to non-carriers, although evidence remains limited in non-European ancestries. While statistically associated with longer sleep tendencies, this genotype has an incremental effect and does not replace the broad influence of environmental factors and overall sleep hygiene.
Carried by roughly 6% to 8% of individuals of European ancestry; it is substantially rarer in East Asian and African populations.
Understanding the rs1191685 Variant
The rs1191685 variant is a single nucleotide polymorphism (SNP) located on chromosome 2. It is classified as an intergenic variant, meaning it resides in the DNA sequence between genes rather than within the coding region of a gene itself. Despite its location outside of a protein-coding sequence, researchers study such variants because they often reside in regulatory regions that can influence how nearby genes are expressed. In the case of rs1191685, it is situated in the genomic neighborhood of the PAX8 gene. Scientists use large-scale genome-wide association studies (GWAS) to compare the DNA of thousands of individuals to see if specific genetic markers appear more frequently in people who share certain traits, such as self-reported sleep duration. This variant has been consistently flagged in these meta-analyses as a locus of interest for sleep-related phenotypes.
The Role of the PAX8 Gene
The PAX8 gene encodes a transcription factor, which is a protein that helps turn other genes on or off. PAX8 is well-known for its critical role in the development of the thyroid gland and the kidneys. Because transcription factors act as master regulators, they can influence a wide array of biological processes. While the primary function of PAX8 is tied to organ development, its proximity to the rs1191685 variant has led researchers to investigate whether it might also play a role in neurological or circadian pathways that regulate sleep. Some studies have explored whether DNA methylation—a chemical modification that can change how genes are expressed—near the PAX8 and PAX8-AS1 loci correlates with objective sleep duration in clinical populations. These findings suggest that the regulatory environment around this gene is complex and may contribute to the biological underpinnings of how long individuals sleep.
Research and Evidence Strength
The evidence linking rs1191685 to sleep duration is categorized as limited in terms of clinical utility. While multiple large-scale GWAS meta-analyses have identified the PAX8 locus as having a statistically significant association with habitual sleep duration, the actual effect size of any single variant is typically very small. For instance, studies have estimated that variants in this region may influence sleep duration by only a few minutes per night. It is important to recognize that sleep duration is a complex, polygenic trait, meaning it is influenced by hundreds of genetic variants, as well as environmental and lifestyle factors. The associations found in research are statistical correlations observed across large populations and do not imply a direct cause-and-effect relationship for any specific individual. Consequently, this variant is not used in clinical settings to predict or diagnose sleep disorders.
What This Information Means for You
If you have received information about your genotype at rs1191685, it is important to view it as a small piece of a much larger biological puzzle. Because the influence of this variant on sleep is minor and the evidence is based on population-level statistics, it cannot be used to determine your personal sleep needs or to diagnose a sleep condition. Genetic markers for complex traits like sleep duration are not deterministic; they do not dictate your behavior or health outcomes. If you are concerned about your sleep quality, duration, or daytime alertness, you should consult with a healthcare professional or a sleep specialist. They can provide personalized guidance based on your clinical history, lifestyle, and objective sleep assessments. Never use genetic information to make changes to your health regimen without first discussing it with a qualified medical provider.
How common is this variant?
The minor allele frequency for rs1191685 is approximately 0.25 to 0.37 in populations of European ancestry.
Frequently asked questions
Can this genetic variant diagnose a sleep disorder?
No. This variant is associated with variations in habitual sleep duration in large population studies, but it is not a diagnostic tool for any sleep disorder or medical condition.
Does having a specific genotype mean I will sleep more or less?
Not necessarily. While statistical associations exist, the effect of this variant on sleep duration is very small and is only one of many genetic and environmental factors that influence how long you sleep.
Should I change my sleep habits based on my genotype?
No. You should not change your sleep habits based on genetic data. If you have concerns about your sleep, please consult a healthcare professional for personalized medical advice.
Is the PAX8 gene only involved in sleep?
No. PAX8 is primarily known for its role in the development of the thyroid gland and kidneys. Its association with sleep is an area of ongoing research into how regulatory regions near the gene might influence circadian or neurological pathways.
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 variant is a well-replicated genome-wide significant locus associated with habitual sleep duration, including both short and long sleep phenotypes.
This intergenic variant near the PAX8 gene is a well-replicated genetic marker associated with variations in habitual sleep duration.
A variant near the PAX8 locus associated with self-reported sleep duration in large population-based cohorts.
This intergenic variant near the PAX8 gene is associated with small, incremental changes in habitual sleep duration.
A genome-wide significant variant located upstream of the PAX8 transcription factor associated with habitual sleep duration.
Genome-wide significant locus associated with average adult self-reported and accelerometer-measured sleep duration.