What you carry at this position in your DNA and what research says about it.
Psoriasis Risk: 10/10 evidence, 7 publications.
You're viewing every possible genotype for this variant.
None of these is your result. Use the genotype toggle to compare them, then sign up and upload your DNA to see which one is yours.
Sample genotype (not yours): A/A
Typical Risk of Psoriasis and Inflammatory Conditions
Baseline risk of inflammatory skin conditions is expected with this common genetic profile.
What this genotype means: Typical risk of psoriasis; Typical risk of psoriatic arthritis.
Sample genotype (not yours): A/T
Increased Risk of Psoriasis and Joint Inflammation
Elevated susceptibility to skin and joint inflammation is associated with this genetic variant.
What this genotype means: Elevated risk of psoriasis; Increased risk of psoriatic arthritis.
Sample genotype (not yours): T/T
Higher Risk of Psoriasis and Joint Inflammation
Stronger genetic predisposition to autoimmune skin and joint conditions is linked to this genotype.
What this genotype means: Significantly elevated risk of psoriasis; Increased risk of psoriatic arthritis.
Gene function and biological role
Gene Function: The IL12B gene encodes the p40 subunit, which is a shared component of both interleukin-12 and interleukin-23 cytokines [1]. These cytokines play a critical role in regulating the immune system's inflammatory response, particularly in directing helper T-cell pathways [1]. Dysregulation of the interleukin-23 pathway is a well-established driver of chronic inflammatory conditions [2]. Consequently, genetic variations in or near IL12B are frequently associated with autoimmune and inflammatory disorders [2].
Variant Impact: The rs12188300 variant is an intergenic genetic marker located near the IL12B gene on chromosome 5 [1]. Although it does not directly alter the protein sequence, it is thought to influence the expression levels of the IL12B gene [2]. This change in expression can shift the balance of inflammatory cytokines in the body [2]. As a result, this variant is strongly linked to susceptibility to several chronic inflammatory diseases [3].
Key Insight: This variant acts as a genetic bridge linking skin inflammation with joint pain and gut health.
Location: IL12B. Chromosome 5 · 5q33.3 · 159.4 Mb
Estimated prevalence by population
Global 89.7%; European 83.4%; African 96.9%; East Asian > 99.9%; South Asian 96.7%; Americas 91.7%; Ashkenazi 89.8%; Finnish 90.6%; Middle Eastern 96.6%; Amish 84.8%.
Estimated AA genotype frequency.
Global 9.9%; European 15.8%; African 3.1%; East Asian < 0.1%; South Asian 3.3%; Americas 8.1%; Ashkenazi 9.9%; Finnish 9.1%; Middle Eastern 3.3%; Amish 14.6%.
Estimated AT genotype frequency.
Global 0.4%; European 0.7%; African < 0.1%; East Asian < 0.1%; South Asian < 0.1%; Americas 0.2%; Ashkenazi 0.3%; Finnish 0.2%; Middle Eastern < 0.1%; Amish 0.6%.
Estimated TT genotype frequency.
Showing effects for A/A genotype
Organ Systems
Skin & Hair Conditions
Psoriasis. Evidence: 10/10. Source: PMID 23143594. Typical Risk.
Immunity & Inflammation
Autoimmune Diseases
Psoriatic Arthritis. Evidence: 4/10. Source: PMID 20953186. Typical Risk.
Ankylosing Spondylitis. Evidence: 6/10. Source: PMID 26974007. Typical Risk.
Chronic Inflammatory Diseases
Crohn's Disease. Evidence: 6/10. Source: PMID 26974007. Typical Risk.
Showing effects for A/T genotype
Psoriasis. Evidence: 10/10. Source: PMID 23143594. Increased Risk.
Psoriatic Arthritis. Evidence: 4/10. Source: PMID 20953186. ~1.7x Risk.
Ankylosing Spondylitis. Evidence: 6/10. Source: PMID 26974007. Increased Risk.
Crohn's Disease. Evidence: 6/10. Source: PMID 26974007. Increased Risk.
Showing effects for T/T genotype
What this genotype means for the people who carry it
Sample genotype: AA (Homozygous)
Inheriting the common A/A genotype means you do not carry the risk-associated T allele at this locus. Large-scale genetic studies have consistently shown that the T allele is the variant that elevates susceptibility to autoimmune skin conditions [1]. Without this risk allele, your genetic predisposition to psoriasis and psoriatic arthritis remains at the typical baseline level [2]. This baseline status also extends to other related inflammatory conditions, such as Crohn's disease and ankylosing spondylitis [3]. Maintaining a healthy lifestyle and protecting your skin barrier are still beneficial for overall skin health. Since you lack the risk variant, your body is less likely to experience the specific cytokine imbalances driven by this locus. Regular skin moisturization and avoiding harsh chemicals can help maintain your natural skin barrier. If you ever experience persistent skin rashes or joint stiffness, consulting a healthcare professional is always recommended.
Typical risk of psoriasis; Typical risk of psoriatic arthritis.
Sample genotype: AT (Heterozygous)
Presence of a single T allele at this locus is associated with a higher susceptibility to psoriasis [1]. The T allele is known to influence the IL12B region, potentially altering the balance of cytokines that drive autoimmune responses [2]. Individuals carrying this variant have an elevated risk of developing psoriatic arthritis, a condition characterized by joint pain and swelling alongside skin symptoms [2]. Furthermore, this genetic marker is linked to other chronic inflammatory conditions, including Crohn's disease and ankylosing spondylitis [3]. While having this variant increases your risk, it does not guarantee you will develop these conditions, as environmental triggers also play a major role. Managing stress and avoiding skin injuries can be helpful preventive strategies. Early detection of joint stiffness or skin changes can lead to more effective management. Discussing this genetic tendency with your doctor can help you stay proactive about your joint and skin health.
Elevated risk of psoriasis; Increased risk of psoriatic arthritis.
Sample genotype: TT (Homozygous)
Double copies of the T allele place you in a higher risk category for developing psoriasis compared to the general population [1]. This genetic variant is located near the IL12B gene, which plays a central role in the body's inflammatory signaling pathways [2]. The presence of two T alleles is associated with a more pronounced susceptibility to psoriatic arthritis, where joint inflammation accompanies skin lesions [2]. Additionally, this genotype is linked to an increased likelihood of other autoimmune and inflammatory conditions, such as Crohn's disease and ankylosing spondylitis [3]. Managing stress, avoiding skin injuries, and consulting a dermatologist if symptoms arise can help manage these risks. Having two copies of the risk allele means your immune system may be more prone to overproducing certain inflammatory cytokines. This heightened inflammatory state can affect both your skin and your joints over time. Proactive lifestyle choices, such as a balanced diet and regular low-impact exercise, can support overall joint and immune health.
Significantly elevated risk of psoriasis; Increased risk of psoriatic arthritis.
Variants with shared genetic architecture
rs2546890 · IL12B Gene · Chr 5 · Autoimmune Disease Risk
rs3213094 · IL12B Gene · Chr 5 · Psoriasis and Biologic Response
rs10045431 · IL12B Gene · Chr 5 · Inflammatory Bowel Disease Risk
Common variants at TRAF3IP2 are associated with susceptibility to psoriatic arthritis and psoriasis.
Identification of 15 new psoriasis susceptibility loci highlights the role of innate immunity.
Content updated August 2026.
ReadYourDNA provides educational interpretation of DNA data you already have. It is not diagnostic, not a substitute for professional medical advice, diagnosis, or treatment, and is not intended to diagnose, treat, cure, or prevent any disease. Talk to a clinician before acting on any result.
Raw DNA Data Reports for 23andMe & AncestryDNA · About ReadYourDNA · FAQ · Methodology & Science · Pricing · Support and complaints · Legal & Contact · Health Traits · Pharmacogenomics · Carrier Status · Variant Explorer · The Human Karyotype · Privacy Policy · Terms of Service · Accessibility · Consumer Health Data Privacy · Your Privacy Choices · Editorial Standards · Your Data, Checkable · Sample Report · ReadYourDNA and Promethease compared · What is inside a 23andMe raw data file · What is inside an AncestryDNA raw data file · What a chatbot can and cannot do with your raw DNA file · Where a raw DNA file can still be uploaded in 2026
Written, maintained and operated by Martin Pechhacker, sole proprietor, Vienna, Austria. Trade register GISA 40064420. support@readyourdna.com