What you carry at this position in your DNA and what research says about it.
Coronary Artery Disease Risk: 8/10 evidence, 17 publications.
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Sample genotype (not yours): C/C
Higher Risk of Coronary Artery Disease
Carrying two copies of the C allele is associated with a significantly higher risk of developing coronary artery disease and experiencing heart attacks. This is driven by reduced expression of the protective TCF21 protein in blood vessels.
What this genotype means: Increased risk of coronary artery disease; Higher risk of myocardial infarction; Slightly higher systolic blood pressure.
Sample genotype (not yours): C/G
Moderately Higher Risk of Coronary Artery Disease
Carrying one copy of the C allele is associated with a moderately increased risk of coronary artery disease and heart attacks. Maintaining a heart-healthy lifestyle is beneficial to mitigate this risk.
What this genotype means: Moderately increased risk of coronary artery disease; Slightly elevated risk of heart attacks; Slightly elevated systolic blood pressure.
Sample genotype (not yours): G/G
Typical Risk of Coronary Artery Disease
Carrying two copies of the G allele is associated with a typical, lower risk of coronary artery disease and heart attacks. This genotype supports optimal expression of the protective TCF21 protein.
What this genotype means: Typical risk of coronary artery disease; Lower risk of myocardial infarction; Typical systolic blood pressure.
Gene function and biological role
Gene Function: The TCF21 gene encodes transcription factor 21, a protein that is vital for the development and maintenance of the cardiovascular system. It regulates how cells in the heart wall differentiate into smooth muscle and fibroblast lineages. In adult blood vessels, TCF21 is highly active during the response to vascular injury, helping to stabilize atherosclerotic plaques. By guiding the behavior of vascular smooth muscle cells, it helps build a protective fibrous cap over fatty deposits in the arteries. This process is crucial for preventing plaque rupture, which is the primary cause of heart attacks.
Variant Impact: The rs12190287 variant is located in the 3 prime untranslated region of the TCF21 gene, a critical regulatory zone. This genetic change alters a binding site for microRNA-224, which directly influences how much TCF21 protein the cell produces. The C allele is associated with reduced expression of TCF21 in vascular smooth muscle cells. Lower levels of this transcription factor impair the cells' ability to transition into protective fibromyocytes within arterial plaques. Consequently, individuals carrying the C allele tend to develop thinner, more fragile fibrous caps over arterial lesions, increasing the risk of cardiovascular events.
Key Insight: This variant affects heart health not by altering cholesterol levels, but by physically changing how blood vessel walls respond to injury and build protective caps over arterial plaques.
Location: TCF21. Chromosome 6 · 6q23.2 · 133.9 Mb
Estimated prevalence by population
Global 49.6%; European 39.7%; African 83.0%; East Asian 33.5%; South Asian 24.7%; Americas 34.8%; Ashkenazi 35.3%; Finnish 29.0%; Middle Eastern 47.7%; Amish 35.6%.
Estimated CC genotype frequency.
Global 38.9%; European 46.6%; African 16.2%; East Asian 48.8%; South Asian 50.0%; Americas 48.4%; Ashkenazi 48.2%; Finnish 49.7%; Middle Eastern 42.7%; Amish 48.1%.
Estimated CG genotype frequency.
Global 11.6%; European 13.7%; African 0.8%; East Asian 17.7%; South Asian 25.3%; Americas 16.9%; Ashkenazi 16.5%; Finnish 21.3%; Middle Eastern 9.6%; Amish 16.3%.
Estimated GG genotype frequency.
Showing effects for C/C genotype
Cardiovascular & Metabolic
Heart Disease
Coronary Artery Disease. Evidence: 8/10. Source: PMID 21378990. Increased Risk.
Heart Attack. Evidence: 8/10. Source: PMID 34594039. Increased Risk.
Hypertension
Blood Pressure. Evidence: 7/10. Source: PMID 39024449. Higher.
Heart Rhythm & Conduction
Cardiac Conduction. Evidence: 8/10. Source: PMID 32439900. Typical.
Organ Systems
Respiratory Health
Lung Function. Evidence: 8/10. Source: PMID 36641522. Slightly Better.
Showing effects for C/G genotype
Coronary Artery Disease. Evidence: 8/10. Source: PMID 21378990. Moderately Increased.
Heart Attack. Evidence: 8/10. Source: PMID 34594039. Moderately Increased.
Blood Pressure. Evidence: 7/10. Source: PMID 39024449. Moderately Higher.
Showing effects for G/G genotype
Coronary Artery Disease. Evidence: 8/10. Source: PMID 21378990. Typical Risk.
Heart Attack. Evidence: 8/10. Source: PMID 34594039. Typical Risk.
Blood Pressure. Evidence: 7/10. Source: PMID 39024449. Typical.
Cardiac Conduction. Evidence: 8/10. Source: PMID 32439900. Slightly Higher.
Lung Function. Evidence: 8/10. Source: PMID 36641522. Typical.
What this genotype means for the people who carry it
Sample genotype: CC (Homozygous)
Presence of the C/C genotype is linked to a higher susceptibility to coronary artery disease and myocardial infarction. This genetic variant reduces the expression of the TCF21 gene in the vascular wall, which impairs the protective remodeling of blood vessels. Specifically, vascular smooth muscle cells are less able to transition into fibromyocytes, resulting in thinner fibrous caps over atherosclerotic plaques. These thinner caps are more prone to rupture, which can trigger sudden blood clots and heart attacks. In addition to coronary artery disease, this genotype is associated with higher systolic blood pressure and a slightly increased risk of hypertension. However, the C allele is also linked to slightly better lung function measurements, such as peak expiratory flow. Managing traditional cardiovascular risk factors like diet, exercise, and blood pressure is highly recommended for individuals with this genotype.
Increased risk of coronary artery disease; Higher risk of myocardial infarction; Slightly higher systolic blood pressure.
Sample genotype: CG (Heterozygous)
A heterozygous C/G genotype is associated with a moderate increase in the risk of coronary artery disease and heart attacks compared to the protective G/G genotype. The presence of one C allele partially reduces the expression of the TCF21 gene in the blood vessels. This reduction slightly limits the ability of vascular smooth muscle cells to migrate and form a robust fibrous cap over arterial plaques. Consequently, plaques may be somewhat less stable and more vulnerable to rupture. Blood pressure levels and hypertension risk also tend to be intermediate for these individuals. On the other hand, the C allele provides a minor positive influence on lung function parameters like peak expiratory flow. Focusing on cardiovascular wellness through regular exercise, a balanced diet, and routine lipid screenings is an effective way to manage this moderate genetic predisposition.
Moderately increased risk of coronary artery disease; Slightly elevated risk of heart attacks; Slightly elevated systolic blood pressure.
Sample genotype: GG (Homozygous)
The homozygous G/G genotype is associated with a lower, typical risk of coronary artery disease and myocardial infarction. Normal, robust expression of the TCF21 gene is maintained in vascular smooth muscle cells. Higher levels of TCF21 protein enable these cells to successfully transition into fibromyocytes, which build thick, stable fibrous caps over arterial plaques. These thick caps are highly resistant to rupture, significantly reducing the likelihood of sudden heart attacks. Systolic blood pressure and the risk of hypertension also tend to be lower. However, the G allele is associated with slightly lower peak expiratory flow, indicating typical rather than enhanced lung function. It is also linked to minor increases in heart rate and PR interval, which generally remain within normal physiological ranges. Overall, this genotype provides a natural protective advantage for cardiovascular health.
Typical risk of coronary artery disease; Lower risk of myocardial infarction; Typical systolic blood pressure.
Variants with shared genetic architecture
rs16986953 · Chr 2 · Heart Disease Risk
rs4977574 · CDKN2B-AS1 Gene · Chr 9 · Heart Disease Risk
rs17465637 · MIA3 Gene · Chr 1 · Heart Disease Risk
Content updated August 2026.
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