rs3091244 — CRP -286C>T>A

CRP Promoter Variant — Genetically Elevated Inflammation at the -286 Position

C-reactive protein is the liver's primary sentinel of systemic inflammation — a pentameric protein synthesized within hours of an IL-6 signal, capable of rising 1,000-fold during acute infection. But the baseline CRP level a person carries when healthy is substantially inherited: genetic factors explain 30–40% of inter-individual variation in resting CRP¹¹ genetic factors explain 30–40% of inter-individual variation in resting CRP
Heritability estimates from twin studies; reviewed in Kathiresan et al. 2006. The rs3091244 variant sits at position -286 in the CRP gene promoter — one of the most functionally important regulatory positions identified for this gene — and is one of the most replicated genetic determinants of circulating CRP concentrations.

This is a triallelic variant, unusual among well-characterized SNPs: the -286 position can carry a C, T, or A allele on the coding strand (equivalent to G, A, or T on the genomic plus strand). Both the T and A coding alleles increase CRP transcription relative to C, with the A allele having the strongest effect. This creates a dosage gradient: CC < CT < TT and CA < AA at this position.

The Mechanism

The -286 position lies within a region of the CRP promoter that binds transcription factors involved in acute-phase gene regulation. Luciferase reporter assays in HepG2 hepatocytes²² Luciferase reporter assays in HepG2 hepatocytes
Wang et al. Frontiers in Immunology 2020 demonstrated that the A and T coding alleles confer significantly higher promoter activity than the C allele, confirming that the variant directly affects transcription rather than mRNA stability or translation. The CRP gene resides on chromosome 1q23.2 and is transcribed from the minus strand; alleles reported in genome files (plus-strand) are the complements of the conventionally cited coding alleles.

The Evidence

In a landmark study of 1,640 Framingham Heart Study participants, Kathiresan et al. (2006)³³ Kathiresan et al. (2006) genotyped 13 CRP polymorphisms and found rs3091244 was the single strongest genetic predictor of serum CRP, with haplotypes carrying the T or A alleles associated with significantly higher levels (stepwise P<0.0001). The SNP explained 1.4% of total CRP variability — modest in isolation but clinically meaningful given that the 12 clinical covariates (including BMI) combined explained 26%.

Crawford et al. (Circulation, 2006)⁴⁴ Crawford et al. (Circulation, 2006) confirmed the association in the diverse NHANES III cohort of 7,159 individuals spanning three ethnic groups. The AA genotype at rs3091244 was associated with elevated serum CRP and, importantly, with prevalent coronary heart disease in non-Hispanic white participants⁵⁵ prevalent coronary heart disease in non-Hispanic white participants
After covariate adjustment, AA genotype associated with CHD; Crawford et al. 2006, establishing the first direct genetic link between this promoter variant and clinical cardiovascular disease endpoints.

The functional impact is also visible in inflammatory disease contexts. In 244 patients with ankylosing spondylitis⁶⁶ 244 patients with ankylosing spondylitis, those carrying the CA genotype (coding) had CRP levels of 18.6 mg/L versus 8.3 mg/L in CC homozygotes (p=0.02), a difference that persisted independent of disease activity scores — demonstrating that this genetic effect is constitutional, not simply a reflection of inflammatory load.

Saratzis et al. (J Vasc Surg, 2014)⁷⁷ Saratzis et al. (J Vasc Surg, 2014) showed that carriers of the rare T (coding A) allele had an odds ratio of 4.88 for abdominal aortic aneurysm in the primary cohort, with larger aneurysm diameters and higher circulating inflammatory markers. This suggests the constitutively elevated CRP from this genotype may directly participate in vessel wall inflammation and structural remodeling.

Mendelian randomization analyses using rs3091244 as a genetic instrument⁸⁸ Mendelian randomization analyses using rs3091244 as a genetic instrument have clarified the causal direction of the BMI–CRP relationship: elevated BMI causally raises CRP, but genetically elevated CRP does not cause weight gain — suggesting CRP is a downstream consequence of metabolic dysfunction rather than a driver of adiposity.

Practical Actions

Knowing your rs3091244 genotype adds resolution to hs-CRP testing. Carriers of the T or A coding allele who show elevated hs-CRP face a compounded risk: genetic predisposition to higher transcription on top of any lifestyle or metabolic contribution. For these individuals, reducing modifiable CRP drivers (visceral adiposity, smoking, physical inactivity) matters more, not less — because the genetic floor is already elevated. Statin therapy lowers CRP by ~37% independent of LDL effects (the JUPITER trial enrolled participants specifically on CRP ≥2 mg/L) and is particularly relevant when genetically elevated CRP co-occurs with borderline LDL.

For GG homozygotes (coding CC), genetic protection does not guarantee low CRP — obesity, smoking, and metabolic syndrome can push any genotype into the elevated range.

Interactions

rs3091244 does not act in isolation. It commonly exists in haplotypes with rs1205, rs1130864, rs2794521, and rs3093059. The combined haplotype architecture — not individual SNPs — best predicts CRP variability in population studies. The rs1205 (3' UTR) variant is the most clinically established companion, and compound haplotype effects have been documented in both cardiovascular and autoimmune disease contexts. If you carry risk alleles at both rs3091244 and rs1205, the additive effect on baseline CRP is larger than either alone.