BHLHE41 rs114138761: What Your Genotype Means
The rs114138761 variant is a rare coding change in the BHLHE41 gene, also known as DEC2. It has been identified in research studies as being associated with a familial natural short sleep phenotype and increased resilience to the effects of sleep deprivation.
What each genotype means
Typical sleep duration
You carry two copies of the standard C allele for the BHLHE41 (DEC2) gene at this locus. Research indicates that individuals with this baseline genotype typically exhibit normal physiological sleep duration requirements of approximately seven to eight hours per night. You do not carry the rare short-sleeper variant associated with reduced sleep need.
Carried by more than 99% of individuals across all major global populations.
Natural short sleeper trait
You carry one copy of the rare T allele (corresponding to p.Tyr362His in BHLHE41/DEC2). Published pedigrees and twin studies link this heterozygous variant to familial natural short sleep, where carriers typically function well on about five to six hours of sleep per night and demonstrate increased resilience to acute sleep restriction. However, the evidence is derived from limited family studies and functional assays, so individual sleep requirements can still vary.
Extremely rare globally, occurring in fewer than 1 in 1,000 individuals outside of specific identified pedigrees.
Homozygous short sleeper variant
You carry two copies of the rare T allele for this BHLHE41 (DEC2) variant. While the heterozygous form is linked to natural short sleep duration and tolerance to sleep restriction, homozygous individuals have rarely or never been documented in population cohorts or published literature. Because data for two copies are virtually absent, exact physiological consequences remain uncertain.
Virtually absent in global population databases such as gnomAD.
Understanding the Variant
The variant rs114138761 is a specific genetic change located within the BHLHE41 gene. In scientific literature, this variant is often referred to by its protein-level change, p.Tyr362His. This means that at position 362 of the BHLHE41 protein, the amino acid tyrosine is replaced by histidine. This type of change is known as a missense mutation, which can potentially alter the function of the protein produced by the gene. Geneticists track this specific location using the rsID rs114138761 to ensure consistency across global research databases. While this variant is located in a gene known for its role in circadian rhythms, it is important to note that the presence of a variant does not automatically guarantee a specific physical trait, as complex biological systems often involve multiple genes and environmental factors working in concert.
The Role of BHLHE41
The BHLHE41 gene, sometimes referred to as DEC2 or SHARP1, encodes a protein that acts as a transcriptional repressor. This means it helps regulate the activity of other genes by 'turning them off' or reducing their expression. BHLHE41 is a key component of the molecular clock, the internal biological mechanism that regulates circadian rhythms—the 24-hour cycles that influence sleep, hormone release, and body temperature. By interacting with other clock proteins like CLOCK and BMAL1, BHLHE41 helps fine-tune the timing of these biological processes. Because of its central role in the circadian system, researchers have long investigated how variations in this gene might influence sleep patterns. When the function of this repressor is altered, it may disrupt the normal feedback loops that govern how long an individual feels the need to sleep, which is why it is a primary candidate in studies of sleep duration.
Research and Evidence
Research into rs114138761 is primarily grounded in studies of 'familial natural short sleep,' a trait where individuals consistently require less sleep than the average person without experiencing the typical negative effects of sleep deprivation. Published studies have observed that carriers of this variant may exhibit shorter nightly sleep durations and show fewer performance lapses during periods of extended wakefulness compared to non-carriers. However, the evidence strength for this association is currently considered limited. Much of the research has been conducted in small, specific pedigrees or twin cohorts rather than large, diverse population-wide studies. Furthermore, recent population-based analyses have suggested that these rare variants do not always correlate with self-reported sleep duration in the general public. This indicates that while the variant may have a significant effect in specific families, its impact in the broader population remains uncertain and requires further investigation.
Population Frequency
The rs114138761 variant is considered rare, with a minor allele frequency (MAF) of less than 0.01 globally. It is most frequently identified in the context of specialized research cohorts, particularly in families that have been specifically recruited due to their unique sleep patterns. Because it is so uncommon in the general population, it is not typically found in standard genetic screening panels. The rarity of this variant makes it difficult to draw broad conclusions about its prevalence across different ancestral groups. Most of the data currently available comes from studies focusing on rare short-sleeper pedigrees, meaning that the frequency of this variant in the general, unselected population is likely very low. Researchers continue to monitor such variants in large-scale genomic databases to better understand their distribution and potential influence on human health.
Interpreting Genetic Information
It is important to understand that identifying a genetic variant like rs114138761 does not constitute a medical diagnosis. The 'short sleeper' trait is generally considered a natural variation rather than a sleep disorder, but individual sleep needs are highly complex and influenced by many factors beyond a single gene. If you are concerned about your sleep quality, duration, or the impact of sleep deprivation on your health, you should consult with a healthcare professional or a sleep specialist. They can provide a comprehensive evaluation that considers your lifestyle, medical history, and overall well-being. Genetic information should be viewed as one small piece of a much larger puzzle. You cannot use this information to self-diagnose or to make changes to your health regimen without professional guidance. Always prioritize evidence-based clinical advice over findings from genetic research databases.
How common is this variant?
The rs114138761 variant is rare, with a global minor allele frequency of less than 0.01, and is primarily enriched in rare pedigrees of natural short sleepers.
Frequently asked questions
Does having this variant mean I am a 'short sleeper'?
Not necessarily. While this variant has been associated with the short sleep phenotype in specific families, it is rare, and many people who sleep for short durations do not carry this specific genetic change.
Can I get tested for this variant to see if I need less sleep?
While some direct-to-consumer genetic tests may include this SNP, it is not a standard clinical test. Because the evidence is limited and the trait is complex, knowing your genotype for this variant is unlikely to provide actionable medical information.
Is the short sleep phenotype considered a medical condition?
No, familial natural short sleep is generally considered a trait or a natural variation in sleep requirement rather than a sleep disorder. However, if you are experiencing chronic sleep issues, you should speak with a doctor.
Does this variant protect me from the health risks of sleep deprivation?
Research suggests some carriers may show resilience to performance lapses during sleep deprivation, but this does not mean they are immune to the long-term health consequences of chronic sleep loss. You should always aim for healthy sleep habits.
Sources & further reading
Educational information only, last refreshed 10/26/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Rare missense variant (p.Pro384Arg) in BHLHE41 (DEC2) associated with the 'short sleep' phenotype, characterized by reduced sleep need and resistance to sleep deprivation.
This missense variant (p.Pro384Arg) is associated with familial natural short sleep (FNSS1), an autosomal dominant trait characterized by a reduced need for sleep.
The P384L missense variant in BHLHE41 (DEC2) reduces core circadian repressor function and leads to a natural short sleep duration phenotype.
Rare missense variant (Tyr362His) in BHLHE41; associated with short sleep duration and resistance to sleep deprivation.
A missense mutation (p.Pro385Arg) in BHLHE41 (DEC2) that confers a natural short sleep phenotype.
This variant is associated with short sleep duration and increased resistance to the effects of sleep deprivation.