LDLR rs121918166: Understanding This Rare Genetic Variant
The rs121918166 variant is a rare genetic change located within the LDLR gene. It is associated with familial hypercholesterolemia, a condition characterized by significantly elevated levels of low-density lipoprotein (LDL) cholesterol in the blood.
What each genotype means
Typical LDL receptor function
This genotype represents the common, non-mutated form of the LDLR gene. It is associated with standard LDL cholesterol processing and does not carry the specific risk for familial hypercholesterolemia linked to this variant. Please consult your healthcare provider for routine cholesterol screening and cardiovascular health management.
This is the most common genotype found in the general population.
Increased familial hypercholesterolemia risk
This genotype indicates the presence of one copy of the variant, which is associated with familial hypercholesterolemia. Individuals with this profile may experience significantly elevated LDL cholesterol levels, which can increase the risk of early-onset cardiovascular disease. Please discuss these results and appropriate lipid-lowering strategies with your clinician or a cardiologist.
This genotype is very rare in the general population.
High familial hypercholesterolemia risk
This genotype indicates the presence of two copies of the variant, which is associated with a severe form of familial hypercholesterolemia. This condition typically leads to very high LDL cholesterol levels and a substantially increased risk of premature heart disease. It is essential to discuss these findings with a medical specialist to manage cholesterol levels and cardiovascular health.
This genotype is extremely rare in the general population.
What is rs121918166?
The rs121918166 variant is a specific alteration in the DNA sequence of the LDLR gene. In genomics, an rsID (reference SNP cluster ID) acts as a unique identifier for a specific location in the human genome where a variation has been observed. This particular variant is categorized as a trait-associated marker. Because it is located within the LDLR gene, it has the potential to influence the structure or function of the protein that the gene encodes. Researchers track such variants to understand how small changes in our genetic code can contribute to differences in health outcomes, particularly those related to metabolic processes like cholesterol regulation.
The Role of the LDLR Gene
The LDLR gene provides the essential instructions for building the low-density lipoprotein receptor protein. These receptors are located on the surface of cells, particularly in the liver, and act like docking stations for LDL particles circulating in the bloodstream. By binding to these particles, the receptors facilitate the removal of LDL cholesterol from the blood, which is a critical step in maintaining healthy cholesterol levels. When the LDLR gene contains a variant that disrupts this process, the receptors may not function correctly or may be produced in insufficient quantities. This leads to an accumulation of LDL cholesterol in the blood, which is a hallmark of familial hypercholesterolemia.
Research and Evidence
Scientific research has established a link between variants in the LDLR gene and familial hypercholesterolemia. The evidence for rs121918166 is currently classified as moderate. Studies in this field often involve analyzing the clinical presentation of individuals who carry the variant, such as their blood cholesterol levels and the presence of physical signs like xanthomas. While the association with elevated LDL cholesterol is well-documented for the LDLR gene as a whole, the specific impact of individual rare variants like rs121918166 requires ongoing investigation. It is important to note that genetic associations are statistical observations across populations and do not necessarily predict the exact health outcome for any single individual.
Population Frequency
The rs121918166 variant is considered very rare across global populations. In genetic studies, variants are often classified by their frequency, and those that are extremely uncommon are frequently studied in the context of rare hereditary disorders. Because this variant is not common in the general population, it is unlikely to be found in standard genetic screening panels unless specifically targeted. Its rarity means that large-scale data on its distribution across different ancestral groups is limited, which is a common characteristic of many rare pathogenic variants identified in clinical research.
What This Information Means for You
If you have encountered this variant in a genetic report, it is important to understand that this information is for educational purposes and does not constitute a medical diagnosis. Genetic variants are only one piece of a complex puzzle that includes lifestyle, diet, and other genetic factors. You cannot use this information to make decisions about your health or medication. If you are concerned about your cholesterol levels or your family history of cardiovascular disease, the most appropriate step is to consult with a healthcare provider or a genetic counselor. They can interpret your results in the context of your overall health and guide you on whether further clinical testing or management is necessary.
How common is this variant?
The rs121918166 variant is documented as very rare in population databases, meaning it is found in only a tiny fraction of the global population.
Frequently asked questions
What is familial hypercholesterolemia?
Familial hypercholesterolemia is an inherited condition that causes very high levels of LDL cholesterol in the blood. It is typically caused by mutations in genes like LDLR that help the body clear cholesterol from the bloodstream.
Can I use this information to diagnose myself?
No, you cannot use genetic information to diagnose yourself. Genetic variants are complex, and a clinical diagnosis requires a professional evaluation by a doctor, including blood tests and a review of your medical history.
Should I change my diet based on this variant?
You should not make changes to your diet or health regimen based solely on a genetic variant. Always discuss your cholesterol levels and any dietary changes with your healthcare provider or a registered dietitian.
Where can I find more information about LDLR?
You can find reliable information about the LDLR gene and its role in health on resources like MedlinePlus Genetics or the NCBI Gene database. These sites provide comprehensive, peer-reviewed summaries of gene functions.
Sources & further reading
Educational information only, last refreshed 10/7/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Pathogenic missense variant altering low-density lipoprotein receptor function and predisposing to severe familial hypercholesterolemia.
This pathogenic variant in the LDLR gene is a contributor to familial hypercholesterolemia, leading to significantly elevated LDL cholesterol levels.
Variant in the LDLR 3' UTR region associated with statin efficacy, often studied in East Asian cohorts.
A variant in the 3' UTR of the LDLR gene associated with variations in statin therapeutic response.
Synonymous variant in the LDLR gene associated with plasma LDL cholesterol levels.
This variant is a well-established marker associated with LDL cholesterol levels and risk of coronary artery disease.