NPSR1 rs324981: Understanding the Asn107Ile Variant
The rs324981 variant is a common genetic change in the NPSR1 gene that results in an amino acid substitution known as Asn107Ile. Research has explored its potential associations with sleep characteristics, such as primary insomnia, as well as certain psychiatric traits.
What each genotype means
Typical baseline sleep duration
Individuals with the AA genotype carry two copies of the ancestral allele, which encodes the Asn107 form of the neuropeptide S receptor 1. In preliminary sleep studies, this genotype has been linked to standard average sleep durations without the modest reduction in total sleep time observed in T allele carriers. However, evidence remains limited and observational, meaning having this genotype does not guarantee specific sleep patterns or resilience against sleep deprivation.
Carried by roughly 30% to 35% of individuals in European populations, with frequencies varying in other global ancestries.
Intermediate sleep duration trait
Carrying one copy of the T allele (Ile107) and one copy of the A allele (Asn107) reflects an intermediate genetic profile in published association studies. Research examining NPSR1 coding variation suggests possible subtle differences in sleep architecture and duration, but the overall phenotypic effect is minor and inconsistent across independent cohorts. This genetic variation represents a mild non-diagnostic predisposition rather than a direct cause of sleep disturbance.
Found in approximately 48% to 50% of individuals of European descent, representing the most common genotype.
Modestly reduced sleep duration
Carriers of the TT genotype have two copies of the Ile107 functional variant, which has demonstrated higher receptor potency in pharmacological assays. Some genetic association studies have linked this homozygous genotype to slightly shorter objective sleep duration (approximately 20 minutes less) and distinct responses to sleep loss, although overall research evidence remains limited. This genotype does not diagnose clinical insomnia or guarantee natural short-sleeper traits, as overall sleep is influenced by numerous lifestyle and genetic factors.
Present in about 18% to 20% of European ancestry populations and less prevalent in several non-European groups.
What is the rs324981 Variant?
The variant rs324981 is a single nucleotide polymorphism (SNP) located within the NPSR1 gene on chromosome 7. Specifically, it is a missense mutation, meaning the change in the DNA sequence leads to a different amino acid being incorporated into the resulting protein. In this case, an asparagine (Asn) is replaced by an isoleucine (Ile) at position 107 of the neuropeptide S receptor 1 protein. Because this variant is found at a high frequency in the general population, it is classified as a polymorphism rather than a rare disease-causing mutation. Scientists study this site because the amino acid change may alter how the receptor functions, potentially influencing how the brain processes specific chemical signals.
The Role of the NPSR1 Gene
The NPSR1 gene encodes the neuropeptide S receptor, a G-protein-coupled receptor found in the brain. This receptor binds to neuropeptide S, a signaling molecule involved in regulating various physiological processes, including anxiety, stress responses, memory consolidation, and sleep-wake cycles. By binding to its receptor, neuropeptide S helps modulate the activity of other neurotransmitter systems, such as serotonin and glutamate. Because of its role in these critical brain functions, researchers have investigated whether variations in the NPSR1 gene might contribute to differences in how individuals respond to stress or maintain healthy sleep patterns. Understanding this gene is part of a broader effort to map how specific brain receptors influence complex human behaviors and mental health traits.
Research and Associations
Scientific literature has explored the potential impact of the Asn107Ile variant on various health-related traits. Some studies have suggested associations between this variant and susceptibility to primary insomnia or differences in sleep debt resilience. Other research has examined its role in psychiatric conditions, with some findings indicating that the variant might influence the age of onset for obsessive-compulsive disorder or relate to verbal memory performance in schizophrenia patients. However, it is important to note that the evidence for these associations is often considered limited or mixed. Many of these studies involve relatively small sample sizes, and results have not always been consistent across different populations. Consequently, while the variant is a subject of active scientific interest, it is not currently used as a diagnostic tool for any medical condition.
Interpreting Your Information
If you have access to your genetic data and see that you carry the rs324981 variant, it is helpful to understand that this is a common genetic feature shared by many people. Genetic associations identified in research studies describe trends across large groups of people and do not predict individual health outcomes. Because the evidence linking this variant to specific traits is still evolving and often inconclusive, this information should not be used to make medical decisions or to self-diagnose. If you have concerns about your sleep quality, mental health, or any other aspect of your well-being, the most appropriate step is to consult with a qualified healthcare professional. They can provide personalized guidance based on your clinical history rather than relying on individual genetic markers.
How common is this variant?
The rs324981 variant is very common, with a minor allele frequency of approximately 0.44 in European populations according to gnomAD data.
Frequently asked questions
Is rs324981 a cause of insomnia?
Research has identified associations between NPSR1 variants and sleep traits, but it is not considered a direct cause of insomnia. Sleep disorders are complex and influenced by many genetic, environmental, and lifestyle factors.
Should I be worried if I have the TT genotype?
No, there is no reason for concern. The rs324981 variant is a common polymorphism found in a large portion of the population, and having a specific genotype does not mean you will develop any particular health condition.
Can I use this information to change my medication?
No. You should never change or stop any medication based on genetic information without first consulting your doctor or pharmacist. They are the only ones who can safely manage your treatment plan.
Where can I find more information about NPSR1?
You can search for the gene symbol NPSR1 on reputable databases like the NIH's MedlinePlus Genetics or the NCBI Gene database. These resources provide scientifically vetted information about gene functions and their roles in human health.
Sources & further reading
Educational information only, last refreshed 10/19/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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The Asn107Ile missense variant in NPSR1 alters neuropeptide S receptor signaling and is linked to variations in sleep duration and architecture.
Missense mutation (Tyr206His) in the neuropeptide S receptor 1 gene associated with a natural short sleep phenotype and potential resilience to sleep deprivation-induced cognitive deficits.
A rare missense variant (p.Tyr206His) in the neuropeptide S receptor 1 conferring natural short sleep duration and resilience to sleep deprivation.