NR3C1 rs6191: Glucocorticoid Receptor and Stress Response
The rs6191 single nucleotide polymorphism is located within the NR3C1 gene, which encodes the human glucocorticoid receptor responsible for orchestrating the physiological response to cortisol. Historically studied alongside or serving as a marker for the classic BclI polymorphism, this variant has been investigated for its influence on hypothalamic-pituitary-adrenal axis sensitivity and cellular responses to glucocorticoids. Published findings show modest associations with stress reactivity and altered corticosteroid response, though clinical evidence remains limited.
What each genotype means
Typical Glucocorticoid Sensitivity
You carry two copies of the C allele, which represents the most common genotype in most ancestral populations. Published studies link this baseline profile with typical glucocorticoid receptor function and standard hypothalamic-pituitary-adrenal axis feedback. Evidence regarding stress resilience and neuroendocrine traits remains limited and variable across different populations.
Carried by approximately 40% to 50% of individuals of European ancestry and at higher rates in East Asian populations.
Altered Stress Feedback Tendency
You carry one copy of the G allele, which has been investigated for subtle influences on glucocorticoid sensitivity and hypothalamic-pituitary-adrenal axis regulation. Some association studies note small shifts in cortisol feedback and stress vulnerability, though clinical findings are modest and inconsistent across cohorts. If you are taking corticosteroid medications, do not make changes without consulting your clinician or pharmacist.
Found in approximately 40% to 45% of individuals of European ancestry and less frequently in other global ancestries.
Heightened Glucocorticoid Sensitivity Tendency
You carry two copies of the minor G allele, a configuration studied for associations with heightened sensitivity of glucocorticoid receptors and modified stress responses. Research suggests this genotype may track with altered endocrine reactivity and suppressed cortisol feedback, though findings are limited and not diagnostic of any disorder. Anyone receiving steroid-based therapies should discuss personalized medication responses directly with a prescribing healthcare provider.
Present in roughly 10% to 15% of people of European descent and observed at lower frequencies in East Asian and African ancestries.
What is the rs6191 Variant?
The single nucleotide polymorphism rs6191 is situated on chromosome 5 within the nuclear receptor subfamily 3 group C member 1 gene ([GeneCards NR3C1 Gene](https://www.genecards.org/card/NR3C1)). In historical molecular genetics literature, this locus has been closely linked with or identified as part of the wider BclI restriction fragment length polymorphism region of the glucocorticoid receptor gene. The variation represents a single-base change that does not alter protein sequence directly, as it resides outside primary coding exons or in regulatory transcript boundaries. Because it sits within non-coding territory, researchers primarily evaluate it as a genetic marker that may influence gene transcription, pre-mRNA processing, or stand in strong linkage disequilibrium with other functional non-coding variants within the locus.
The Biological Role of NR3C1 and Glucocorticoid Signaling
The NR3C1 gene provides instructions for producing the glucocorticoid receptor, a ligand-activated transcription factor that controls cellular responses to cortisol and therapeutic steroids ([Harmonizome NR3C1 Summary](https://maayanlab.cloud/Harmonizome/gene/NR3C1)). When cortisol binds to the glucocorticoid receptor in the cytoplasm, the receptor complex translocates into the nucleus. There, it modulates transcription through glucocorticoid response elements or interacts with other transcriptional factors to regulate systemic inflammation, metabolic homeostasis, and stress adaptations. The receptor is also essential for negative feedback in the hypothalamic-pituitary-adrenal axis, signalling the brain and pituitary gland to suppress excess hormone output once a challenge has subsided.
Scientific Findings: Stress Reactivity and Glucocorticoid Sensitivity
Pharmacogenetic and endocrine studies have explored rs6191 and its linked BclI haplotype to understand inter-individual differences in cortisol dynamics. Cohort research in pediatric and adult populations suggests that variant alleles in this region are associated with increased in vitro glucocorticoid sensitivity and heightened cortisol suppression following low-dose dexamethasone exposure ([PMC3376441](https://pmc.ncbi.nlm.nih.gov/articles/PMC3376441/)). Other investigations have examined potential links to neuropsychiatric traits, including stress-related conditions and schizophrenia susceptibility ([Wiley Journal of Neurochemistry 2026](https://onlinelibrary.wiley.com/doi/10.1002/jdn.70134)). However, the overall evidence strength remains limited: findings vary significantly across different cohorts, effect sizes are generally small, and associations often fail to meet stringent genome-wide significance thresholds in large-scale meta-analyses.
How to Interpret Your Genetic Data
Genetic findings at rs6191 describe statistical associations across research cohorts rather than deterministic biological outcomes. Carrying one or two copies of a variant allele does not mean an individual has an adrenal disorder or a dysfunctional stress response. Epigenetic factors, early-life environmental exposures, diet, and lifestyle contribute extensively to hypothalamic-pituitary-adrenal axis function alongside genetics. Furthermore, this variant is not an approved diagnostic marker for any medical condition, nor does it provide a stand-alone guide for medical treatment. Anyone taking corticosteroid medications should never adjust dosages based on consumer genetic tests, but should instead consult a licensed clinician or pharmacist.
How common is this variant?
The minor allele (G) frequency sits at approximately 0.35 in European populations, while allele frequencies can vary significantly across non-European ancestral cohorts according to reference databases like dbSNP.
Frequently asked questions
Does having the rs6191 variant mean I have high cortisol?
No, having the rs6191 variant does not mean you have high or abnormal cortisol levels. Genetic studies only explore subtle shifts in receptor sensitivity and negative feedback regulation across broad populations. Daily hormone levels are primarily regulated by sleep, chronic stress, circadian rhythms, and overall endocrine health.
How does rs6191 relate to the BclI polymorphism?
Historically, researchers used the BclI restriction enzyme to identify a specific variation in the NR3C1 gene linked to altered steroid responsiveness. Modern genomic studies frequently track rs6191 and neighboring SNPs as genomic markers that capture the variation formerly identified via the BclI restriction fragment.
Can this genotype guide my steroid medication dose?
No, rs6191 is not currently recommended by clinical pharmacogenomics consortia (such as CPIC) to dictate medication dosages. If you take glucocorticoid drugs such as prednisone, dexamethasone, or methylprednisolone, any treatment plans or dosage adjustments must be directed by your healthcare provider.
Why is the evidence for rs6191 categorized as limited?
While multiple laboratory studies note differences in lymphocyte sensitivity or cortisol suppression tests, large-scale studies often report mixed or ancestry-specific results. Because sample sizes in historical candidate-gene studies were modest, the variant does not carry definitive diagnostic or clinical significance.
Sources & further reading
Educational information only, last refreshed 9/14/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Get my report — $29Related variants in NR3C1
Known as the BclI intronic variant of the glucocorticoid receptor gene, associated with hypersensitivity to cortisol and altered HPA-axis negative feedback.
Variant in the 3-prime untranslated region of the glucocorticoid receptor gene associated with altered cortisol sensitivity, blood pressure responses, and nutrient-driven metabolic stress.
Variant in the glucocorticoid receptor gene (GR-9beta) that increases glucocorticoid receptor beta expression and promotes glucocorticoid resistance during physiological and psychological stress.
Intronic variant within the glucocorticoid receptor gene NR3C1 modulating feedback inhibition of the HPA axis and baseline stress resilience.
Known as R23K, this variant is associated with glucocorticoid sensitivity and altered cortisol awakening response.
Rare variant in the glucocorticoid receptor gene (NR3C1).