What you carry at this position in your DNA and what research says about it.
Alzheimer and Heart Risk: 10/10 evidence, 96 publications.
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Sample genotype (not yours): A/A
Typical Alzheimer and Heart Risk
This genotype is associated with baseline risk levels for late-onset Alzheimer's disease and typical LDL cholesterol levels. It represents the most common genetic profile globally.
What this genotype means: Typical risk for late-onset Alzheimer's disease; Baseline LDL and total cholesterol levels; Slightly higher C-reactive protein levels.
Sample genotype (not yours): A/G
Increased Alzheimer and Heart Risk
Carrying one G allele is linked to a roughly three-fold increase in Alzheimer's risk and moderately higher LDL cholesterol. It may also slightly reduce your response to statin medications.
What this genotype means: Moderately increased risk for late-onset Alzheimer's; Elevated LDL and total cholesterol levels; Potentially reduced response to statin medications.
Sample genotype (not yours): G/G
Elevated Alzheimer and Heart Risk
Carrying two G alleles is linked to a two- to three-fold increase in Alzheimer's risk and elevated LDL cholesterol. It also correlates with a weaker response to statin therapy.
What this genotype means: Significantly increased risk for late-onset Alzheimer's; Higher baseline LDL and total cholesterol; Diminished cholesterol-lowering response to statins.
Gene function and biological role
Gene Function: The APOC1 gene encodes apolipoprotein C1, a key component of lipoprotein particles that helps govern how cholesterol and triglycerides are transported through the bloodstream. It belongs to a tightly clustered family of apolipoprotein genes on chromosome 19, positioned right alongside the highly studied APOE gene. Because of this close physical proximity, genetic variations in APOC1 are frequently inherited together with variations in APOE [1]. This genetic linkage means that APOC1 plays an important, cooperative role in both lipid metabolism and the clearance of proteins in the brain [2].
Variant Impact: This variant, rs4420638, is a single nucleotide change located downstream of the APOC1 gene. It serves as a strong genetic proxy for the well-known APOE4 risk allele due to high linkage disequilibrium [3]. The G version of this variant is consistently linked to higher levels of low-density lipoprotein (LDL) cholesterol and total cholesterol [4]. Additionally, it correlates with a higher risk of developing late-onset Alzheimer's disease and coronary artery disease [3] [4].
Key Insight: Because this variant is located extremely close to the APOE gene, it acts as a genetic mirror, reflecting your likelihood of carrying the APOE4 allele. However, this relationship is not a perfect match, meaning further direct genotyping of APOE is often recommended for absolute certainty.
Location: APOC1. Chromosome 19 · 19q13.32 · 44.9 Mb
Estimated prevalence by population
Global 67.4%; European 68.1%; African 63.4%; East Asian 78.6%; South Asian 75.6%; Americas 79.1%; Ashkenazi 72.3%; Finnish 50.2%; Middle Eastern 71.6%; Amish 64.5%.
Estimated AA genotype frequency.
Global 29.2%; European 28.9%; African 32.5%; East Asian 20.1%; South Asian 22.7%; Americas 19.6%; Ashkenazi 25.5%; Finnish 41.3%; Middle Eastern 26.1%; Amish 31.6%.
Estimated AG genotype frequency.
Global 3.4%; European 3.1%; African 4.2%; East Asian 1.3%; South Asian 1.7%; Americas 1.2%; Ashkenazi 2.2%; Finnish 8.5%; Middle Eastern 2.4%; Amish 3.9%.
Estimated GG genotype frequency.
Showing effects for A/A genotype
Neurology & Mental Health
Neurodegenerative Diseases
Alzheimer's Disease. Evidence: 10/10. Source: PMID 17474819. Typical Risk.
Cardiovascular & Metabolic
Lipids & Cholesterol
LDL Cholesterol. Evidence: 10/10. Source: PMID 18193043. Typical Levels.
Heart Disease
Coronary Artery Disease. Evidence: 8/10. Source: PMID 26343387. Typical Risk.
Immunity & Inflammation
Inflammatory & Circulating Protein Markers
C-Reactive Protein. Evidence: 10/10. Source: PMID 19567438. Higher Levels.
Pharmacogenomics
Lipid-Lowering Drug Response
Statin Response. Evidence: 5/10. Source: PMID 27648687. Typical Response.
Showing effects for A/G genotype
Alzheimer's Disease. Evidence: 10/10. Source: PMID 17474819. ~3x Increased Risk.
LDL Cholesterol. Evidence: 10/10. Source: PMID 18193043. Increased Levels.
Coronary Artery Disease. Evidence: 8/10. Source: PMID 26343387. ~1.1x Increased Risk.
C-Reactive Protein. Evidence: 10/10. Source: PMID 19567438. Typical Levels.
Statin Response. Evidence: 5/10. Source: PMID 27648687. Poorer Response.
Showing effects for G/G genotype
Alzheimer's Disease. Evidence: 10/10. Source: PMID 17474819. 2x+ Increased Risk.
LDL Cholesterol. Evidence: 10/10. Source: PMID 18193043. Higher Levels.
Coronary Artery Disease. Evidence: 8/10. Source: PMID 26343387. ~1.2x Increased Risk.
C-Reactive Protein. Evidence: 10/10. Source: PMID 19567438. Lower Levels.
What this genotype means for the people who carry it
Sample genotype: AA (Homozygous)
Carrying two copies of the A allele is considered the baseline or normal profile for this genetic region [1]. Individuals with this genotype do not carry the elevated risk for late-onset Alzheimer's disease associated with the G allele [2]. Lipid profiles, including LDL cholesterol and total cholesterol, generally remain within typical ranges [3]. However, this genotype is associated with slightly higher levels of C-reactive protein, a marker of systemic inflammation [4]. Because this variant is a proxy, it suggests you are highly unlikely to carry the high-risk APOE4 allele, though direct APOE testing remains the gold standard for confirmation [1].
Typical risk for late-onset Alzheimer's disease; Baseline LDL and total cholesterol levels; Slightly higher C-reactive protein levels.
Sample genotype: AG (Heterozygous)
Having one copy of the G allele significantly shifts both cardiovascular and neurological risk profiles. This genotype is associated with an estimated three-fold increase in the risk of developing late-onset Alzheimer's disease [1]. On the cardiovascular side, it is linked to higher levels of LDL and total cholesterol, as well as a 1.4-fold increase in coronary heart disease risk [2] [3]. Research also indicates a potentially reduced cholesterol-lowering response when taking standard statin therapies [4]. Conversely, this genetic profile correlates with lower circulating levels of C-reactive protein, which is a marker of systemic inflammation [5].
Moderately increased risk for late-onset Alzheimer's; Elevated LDL and total cholesterol levels; Potentially reduced response to statin medications.
Sample genotype: GG (Homozygous)
Carrying two copies of the G allele places you in a higher risk category for both cognitive decline and cardiovascular issues. This profile is strongly associated with a two- to three-fold increase in late-onset Alzheimer's disease risk, often reflecting the presence of the APOE4 allele [1]. It is also linked to elevated LDL and total cholesterol levels, which can contribute to a higher risk of coronary artery disease [2] [3]. Additionally, clinical studies suggest that individuals with this genotype may experience a less pronounced reduction in LDL cholesterol when treated with statins [4]. On a positive note, this genotype is associated with the lowest levels of C-reactive protein, indicating reduced systemic inflammation [5]. Direct testing of the APOE gene is highly recommended to clarify your exact risk profile [1].
Significantly increased risk for late-onset Alzheimer's; Higher baseline LDL and total cholesterol; Diminished cholesterol-lowering response to statins.
Variants with shared genetic architecture
rs438811 · APOC1 Gene · Chr 19 · Alzheimer and Lipid Risk
rs445925 · APOC1 Gene · Chr 19 · Cholesterol and Heart Risk
rs56131196 · APOC1 Gene · Chr 19 · Alzheimer and Heart Risk
Does APOE explain the linkage of Alzheimer's disease to chromosome 19q13?
Genome-wide association analysis of age-at-onset in Alzheimer's disease.
Biological, clinical and population relevance of 95 loci for blood lipids.
Genetic Loci associated with C-reactive protein levels and risk of coronary heart disease.
Content updated August 2026.
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