What you carry at this position in your DNA and what research says about it.
Autoimmune and Heart Health: 10/10 evidence, 59 publications.
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Sample genotype (not yours): C/C
Higher Risk of Autoimmune and Cardiovascular Conditions
Carrying two copies of the C allele is associated with an increased risk of celiac disease, high blood pressure, and arterial disease. However, it may offer a slight protective effect against asthma and high cholesterol.
What this genotype means: Increased risk of celiac disease; Higher diastolic blood pressure; Elevated risk of heart attack.
Sample genotype (not yours): C/T
Moderate Risk of Autoimmune and Cardiovascular Conditions
Carrying one copy of the C allele represents an intermediate genetic profile, with moderate risks for celiac disease and high blood pressure. It balances these with a moderate risk for asthma and elevated cholesterol.
What this genotype means: Moderately increased risk of celiac disease; Slightly elevated blood pressure; Slightly increased risk of asthma.
Sample genotype (not yours): T/T
Lower Risk of Autoimmune and Cardiovascular Conditions
Carrying two copies of the T allele is associated with a lower risk of celiac disease, high blood pressure, and heart disease. However, it is linked to a slightly higher risk of asthma and elevated cholesterol.
What this genotype means: Lower risk of celiac disease; Healthy blood pressure levels; Slightly higher risk of asthma and cholesterol.
Gene function and biological role
Gene Function: The ATXN2 gene encodes the ataxin-2 protein, which is involved in regulating RNA translation and cellular stress responses. Although mutations in this gene are famously known for causing spinocerebellar ataxia type 2, common variations in its locus have far-reaching effects on the immune system and blood vessels [1]. This gene sits in a highly active genomic region on chromosome 12, directly adjacent to and in tight linkage with the SH2B3 gene [2]. Together, these genes form a critical regulatory hub that influences the development of immune cells, inflammatory pathways, and vascular homeostasis [3]. Consequently, variations here are linked to a wide spectrum of autoimmune disorders and cardiovascular traits [4].
Variant Impact: The rs653178 variant is an intronic change located within the ATXN2 gene that serves as a strong genetic marker for immune and vascular function. This variant is inherited in near-complete linkage with a functional missense mutation in the neighboring SH2B3 gene, meaning they almost always travel together [2]. The genetic variation alters the expression of key proteins that regulate white blood cell production and inflammatory signaling [5]. Because of this profound impact on the immune system, the variant acts as a major pleiotropic locus, simultaneously affecting susceptibility to gut inflammation, blood pressure regulation, and arterial health [6].
Key Insight: This single genetic marker acts as a major biological pivot, balancing your risk between autoimmune cardiovascular issues and respiratory allergies.
Location: ATXN2. Chromosome 12 · 12q24.12 · 111.6 Mb
Estimated prevalence by population
Global 14.3%; European 23.8%; African 0.7%; East Asian < 0.1%; South Asian 0.9%; Americas 8.6%; Ashkenazi 45.0%; Finnish 16.6%; Middle Eastern 13.7%; Amish 21.2%.
Estimated CC genotype frequency.
Global 36.5%; European 50.0%; African 15.1%; East Asian 0.4%; South Asian 17.0%; Americas 41.5%; Ashkenazi 44.2%; Finnish 48.3%; Middle Eastern 46.6%; Amish 49.7%.
Estimated CT genotype frequency.
Global 49.3%; European 26.2%; African 84.3%; East Asian 99.6%; South Asian 82.1%; Americas 49.9%; Ashkenazi 10.9%; Finnish 35.1%; Middle Eastern 39.7%; Amish 29.1%.
Estimated TT genotype frequency.
Showing effects for C/C genotype
Immunity & Inflammation
Autoimmune Diseases
Celiac Disease. Evidence: 7/10. Source: PMID 18311140. Higher Risk.
Cardiovascular & Metabolic
Hypertension
Blood Pressure. Evidence: 10/10. Source: PMID 19430483. Higher Pressure.
Heart Disease
Heart Attack. Evidence: 6/10. Source: PMID 26343387. Higher Risk.
Lipids & Cholesterol
Cholesterol Levels. Evidence: 10/10. Source: PMID 30275531. Lower Levels.
Organ Systems
Respiratory Health
Asthma. Evidence: 8/10. Source: PMID 31361310. Lower Risk.
Showing effects for C/T genotype
Celiac Disease. Evidence: 7/10. Source: PMID 18311140. Moderate Risk.
Blood Pressure. Evidence: 10/10. Source: PMID 19430483. Slightly Elevated.
Heart Attack. Evidence: 6/10. Source: PMID 26343387. Slightly Elevated.
Cholesterol Levels. Evidence: 10/10. Source: PMID 30275531. Slightly Elevated.
Asthma. Evidence: 8/10. Source: PMID 31361310. Slightly Elevated.
Showing effects for T/T genotype
Celiac Disease. Evidence: 7/10. Source: PMID 18311140. Typical Risk.
Blood Pressure. Evidence: 10/10. Source: PMID 19430483. Typical Pressure.
Heart Attack. Evidence: 6/10. Source: PMID 26343387. Typical Risk.
Cholesterol Levels. Evidence: 10/10. Source: PMID 30275531. Higher Levels.
Asthma. Evidence: 8/10. Source: PMID 31361310. Higher Risk.
What this genotype means for the people who carry it
Sample genotype: CC (Homozygous)
Having two copies of the C allele significantly elevates the likelihood of developing celiac disease, an autoimmune reaction to gluten [1]. This genotype is also strongly linked to higher diastolic blood pressure and an increased risk of hypertension [2]. Furthermore, it is associated with elevated risks for peripheral arterial disease and myocardial infarction, commonly known as a heart attack [3]. The underlying biology suggests that this genetic profile promotes heightened inflammatory responses and altered immune cell counts, particularly eosinophils [4]. Interestingly, while it increases susceptibility to autoimmune conditions like Crohn's disease and lupus, it correlates with lower total cholesterol levels and a reduced risk of asthma [5].
Increased risk of celiac disease; Higher diastolic blood pressure; Elevated risk of heart attack.
Sample genotype: CT (Heterozygous)
Inheriting one C allele and one T allele results in a balanced but intermediate risk profile across multiple health traits. This genetic makeup is associated with a moderate increase in the risk of celiac disease compared to the baseline [1]. Blood pressure levels and the risk of developing hypertension are also moderately elevated [2]. On the cardiovascular front, there is a slight increase in susceptibility to peripheral arterial disease [3]. Conversely, the presence of the T allele slightly increases the risk of asthma and allergic rhinitis compared to the C/C genotype, while also raising total cholesterol levels [4]. This combination highlights the complex trade-offs of this highly pleiotropic locus, where immune activation and lipid metabolism are finely balanced [5].
Moderately increased risk of celiac disease; Slightly elevated blood pressure; Slightly increased risk of asthma.
Sample genotype: TT (Homozygous)
Having two copies of the T allele provides significant protection against several major autoimmune and cardiovascular conditions. This genotype is associated with the lowest risk of developing celiac disease and other inflammatory bowel disorders [1]. It is also linked to lower diastolic blood pressure and a reduced likelihood of hypertension [2]. Additionally, the risk of experiencing a heart attack or developing peripheral arterial disease is minimized [3]. However, this genetic profile is associated with a higher susceptibility to asthma, eczema, and allergic rhinitis [4]. It also correlates with slightly higher total and LDL cholesterol levels, requiring closer attention to dietary habits [5].
Lower risk of celiac disease; Healthy blood pressure levels; Slightly higher risk of asthma and cholesterol.
Variants with shared genetic architecture
rs10774625 · ATXN2 Gene · Chr 12 · Cardiovascular Health
rs4766578 · ATXN2 Gene · Chr 12 · Heart Disease Risk
rs597808 · ATXN2 Gene · Chr 12 · Heart and Colon Health
Positive selection of a pre-expansion CAG repeat of the human SCA2 gene.
Thrombotic antiphospholipid syndrome shows strong haplotypic association with SH2B3-ATXN2 locus.
Complex genetic signatures in immune cells underlie autoimmunity and inform therapy.
Newly identified genetic risk variants for celiac disease related to the immune response.
Genome-wide association study identifies eight loci associated with blood pressure.
The Allelic Landscape of Human Blood Cell Trait Variation and Links to Common Complex Disease.
Multiple common variants for celiac disease influencing immune gene expression.
Genetics of blood lipids among ~300,000 multi-ethnic participants of the Million Veteran Program.
Content updated August 2026.
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