PSRC1 Genotype

Two people can eat the same food, live the same life, and end up with very different cholesterol numbers and very different odds of a heart attack. A chunk of that difference is written into your DNA at birth, and one of the most studied stretches sits at a region of chromosome 1 that includes the PSRC1 (proline/serine-rich coiled-coil 1) gene. The variants you inherit here help set your baseline LDL cholesterol and shift your lifetime odds of coronary artery disease.

This is an exploratory genetic marker, not a routine clinical test. Knowing your genotype will not replace your lipid panel, but it adds a layer of context that a standard panel cannot show. It helps explain why your cholesterol behaves the way it does, and it may modestly shift expectations for how strongly statins will work for you.

What This Gene Actually Does

PSRC1 sits inside a tight cluster of three genes on chromosome 1, alongside CELSR2 and SORT1. Together this cluster, often called the CELSR2-PSRC1-SORT1 region, is one of the strongest genetic signals ever found for LDL cholesterol and coronary artery disease (CAD).

The PSRC1 gene itself codes for a protein involved in cell division. But the variants in and around it act mostly by changing how much of the nearby liver proteins get made. The simplest version of the story is that higher liver expression of this cluster tracks with lower LDL and lower CAD risk in population studies. The full picture is messier: the SORT1 protein (sortilin) appears to have dual roles in the liver, both helping export cholesterol-carrying particles and influencing their clearance, and researchers are still working out how those roles balance out. The net population-level signal is consistent, even if the cell-by-cell mechanism is still being debated.

Heart Disease Risk

Variants in this cluster are some of the most consistent genetic predictors of coronary artery disease found in large population studies. Two of the most studied are rs599839 and rs646776. Both have been linked to higher risk of heart attack and coronary disease across many populations.

Sources: Castillo-Avila et al. 2023 meta-analysis (rs599839 and rs646776); Noto et al. 2021 (rs629301).

What this means for you: if you carry one of these risk alleles, your starting line for heart disease risk is moved slightly forward, regardless of how your standard lipid numbers look in any given year. That makes earlier and more aggressive attention to the other levers of cardiovascular risk worth considering.

Effects on Cholesterol Levels

The same variants that raise heart disease risk also raise cholesterol. At the PSRC1/CELSR2 locus, each copy of the rs599839 risk allele has been associated with modestly higher total cholesterol, almost entirely driven by LDL cholesterol. The rs629301 T/T genotype has been tied to higher LDL, higher non-HDL cholesterol, higher ApoB (apolipoprotein B, the protein wrapped around every LDL particle), and lower HDL.

Variants that increase the activity of the PSRC1, CELSR2, and SORT1 genes in the liver have the opposite effect: lower LDL cholesterol, lower triglycerides, and lower CAD risk. In one analysis using whole-blood expression as a proxy, each one-standard-deviation increase in genetically-determined PSRC1 expression was associated with 18% lower odds of developing coronary artery disease.

How Strongly Statins Work

In a large pharmacogenetic meta-analysis of LDL response to statins, two variants in the SORT1/CELSR2/PSRC1 region, including rs646776, were tied to a slightly stronger LDL drop on statin therapy. The effect per allele is small, only a few percent on LDL, and the Heart Protection Study found that the reduction in vascular events with simvastatin was similar regardless of genotype at this locus.

What this means for you: this is an interesting biological signal, but it is not a reason to choose or skip a statin. Your genotype here may nudge expectations for how much LDL will fall on a given dose, but the underlying message from the trial data is that the benefit of statins on heart attacks and strokes does not appear to hinge on what you carry at this locus.

Beyond Cholesterol: Blood Clotting and Metabolism

The LDL-lowering allele of rs12740374, another variant in this cluster, has also been linked to lower levels of protein C, a clotting regulator. This hints at a quiet connection between how the liver handles cholesterol and how blood clots, though the practical implications for an individual reader are still unclear.

Separately, rs12740374 has been linked to a lower resting metabolic rate (measured in about 509 adults) and to changes in muscle energy handling (seen in a smaller muscle-biopsy subgroup of about 207 people). These are early findings from a single research group, so treat them as scientifically interesting rather than clinically actionable.

The Counterintuitive Liver Finding

There is one pattern in the data that runs against the obvious story. In people who already have non-alcoholic fatty liver disease (NAFLD), the rs599839 G allele that protects against high cholesterol and cardiovascular disease has also been linked to higher hepatic PSRC1 expression and a higher risk of liver cancer (hepatocellular carcinoma), independent of how scarred the liver already is.

Here is how to hold both findings at once: the PSRC1 cluster does two different jobs. In the liver's cholesterol machinery, more PSRC1 activity tracks with better LDL clearance from the bloodstream, which is good for your arteries. Inside liver cells under chronic stress, the same protein helps drive cell division, which can fuel tumor growth. The variant is not simply good or bad. It is a phenotype switch whose net effect depends on the rest of your biology, especially whether you have existing liver disease.

Ancestry Matters

Risk variants in this cluster have been linked to cardiovascular disease across European, Hispanic, and Asian populations, but the strength of the signal varies. For rs646776, the link to cardiovascular disease was particularly strong in Asian cohorts. In Hispanic populations, genetically predicted PSRC1 expression has tracked consistently with LDL and total cholesterol. The takeaway: this is one of the few genetic cardiovascular signals with reasonable evidence across multiple ancestries, though risk allele frequency and effect size are not identical everywhere.

One-Time Test, Lifetime Use

Your DNA does not change. The genotype you get today is the genotype you would get next year, in ten years, and at the end of your life. There is no reason to repeat this test, and no "trend" to track for the variant itself.

What does need ongoing tracking is the downstream phenotype: your actual cholesterol levels and inflammatory markers. If you carry risk alleles in this cluster, a reasonable cadence is a baseline lipid panel including ApoB, a recheck in 3 to 6 months if you start any new intervention, and at least annual monitoring after that. The value of this genetic test compounds over years as you fold it into ongoing decisions about cholesterol targets, statin choices, and how aggressive to be with prevention.

When Results Can Be Misleading

• Panel coverage limits: the assay only reports the specific variants it is designed to detect. A result that does not flag a risk variant does not rule out rare or uncommon variants elsewhere in the PSRC1, CELSR2, or SORT1 genes.
• Ancestry-specific frequencies: the risk alleles in this cluster are more common in some ancestry groups than others. The clinical meaning of a result depends partly on your background.
• Variants of uncertain significance: occasionally a panel flags a change in this region whose effect on disease risk is not yet known. Treat these as questions, not answers.
• Direct-to-consumer reports: results from consumer-grade ancestry services may report variants at this locus, but coverage and accuracy vary. Clinical-grade testing is more reliable for medical decisions.

What to Do With an Out-of-Pattern Result

A genotype is most useful when you combine it with phenotype data. If your result shows a risk allele in this cluster, the next moves are not about retesting the gene. They are about getting a complete cardiovascular picture: a full lipid panel including ApoB and Lp(a) (lipoprotein little-a, an inherited cholesterol particle that runs separately from standard LDL), a high-sensitivity CRP (C-reactive protein) for inflammation, and an HbA1c for metabolic context. A coronary calcium scan can show whether genetic risk has already translated into early plaque.

If the pattern that emerges is high ApoB plus risk alleles in this cluster plus any family history of early heart attack or stroke, a conversation with a lipidologist or cardiologist about earlier and more aggressive lipid management is reasonable. If your result shows protective alleles but you still have a strong family history of heart disease, do not relax. This is one signal in a much larger picture, and other genes, lifestyle, and standard risk factors all still matter.

Because this variant runs in families, first-degree relatives, your parents, siblings, and children, share roughly half your DNA on average. A finding here is worth a conversation with them, especially if cardiovascular disease has already shown up in the family tree.