LDLR rs121908076: Understanding This Rare Genetic Variant
The rs121908076 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 LDLR function
You carry two copies of the common reference allele at this position in the LDLR gene. This genotype is associated with normal low-density lipoprotein receptor function and does not confer inherited risk for familial hypercholesterolemia via this specific variant. Baseline cardiovascular risk should still be evaluated through standard clinical lipid panels and lifestyle factors.
Carried by more than 99.9% of individuals across all major global populations.
Elevated familial hypercholesterolemia risk
You carry one copy of the rare pathogenic nonsense alteration (c.501C>A, historically also noted as p.Cys167Ter or Cys146X), which disrupts receptor production through premature protein truncation. Large clinical registries and research studies link this heterozygous genotype to autosomal dominant familial hypercholesterolemia, marked by significantly elevated LDL cholesterol and higher risk of early-onset coronary artery disease. Individuals with this genotype typically discuss formal lipid monitoring, lifestyle considerations, and lipid-lowering management plans with a medical specialist.
Extremely rare; observed in fewer than 1 in 10,000 individuals globally and essentially absent in general population databases like gnomAD.
Severe familial hypercholesterolemia risk
You carry two copies of the rare truncating variant, which causes severe or near-complete deficiency in low-density lipoprotein receptor activity. Research associates homozygous loss-of-function variants in the LDLR gene with homozygous familial hypercholesterolemia, an exceptionally severe condition characterized by profoundly elevated childhood LDL levels and accelerated premature cardiovascular disease. Specialized clinical evaluation and advanced lipid management therapies are routinely recommended for individuals with this genotype.
Extremely rare worldwide, typically documented only in isolated clinical case reports or consanguineous families.
What is rs121908076?
The rs121908076 variant is a specific single nucleotide polymorphism (SNP) found within the LDLR gene. In genetics, a SNP represents a variation at a single position in the DNA sequence. This particular variant is classified as a missense mutation, meaning the change in the DNA code results in the production of a different amino acid during the synthesis of the LDL receptor protein. Because the LDL receptor is critical for clearing cholesterol from the bloodstream, alterations in its structure can disrupt its normal function. This variant is cataloged in scientific databases as a pathogenic variant, meaning it is linked to the development of familial hypercholesterolemia. Researchers study such variants to understand how specific molecular changes contribute to metabolic health and the risk of cardiovascular disease.
The Role of the LDLR Gene
The LDLR gene provides the essential instructions for creating the low-density lipoprotein receptor. This protein is found on the surface of cells, particularly in the liver, where it acts like a docking station for LDL particles—often referred to as 'bad' cholesterol—circulating in the blood. Once the LDL particle binds to the receptor, the cell internalizes it, effectively removing the cholesterol from the bloodstream and regulating its levels. When the LDLR gene contains a pathogenic variant, the resulting receptor may be missing, malformed, or unable to bind to LDL particles efficiently. This failure in the clearance mechanism leads to an accumulation of LDL cholesterol in the blood, which is a primary risk factor for the development of atherosclerosis and early-onset cardiovascular disease.
Research and Clinical Evidence
Scientific research classifies rs121908076 as a pathogenic variant associated with familial hypercholesterolemia. Evidence for this association is derived from clinical studies and genetic curation efforts that evaluate how specific mutations impact protein function. While many variants in the LDLR gene are well-characterized, some remain classified as variants of unknown significance until further functional studies are performed. For rs121908076, the evidence points toward a disruption in the receptor's ability to manage cholesterol levels. It is important to note that the presence of a pathogenic variant does not guarantee a specific clinical outcome, as individual health is influenced by a complex interplay of genetics, lifestyle, and environment. Clinicians use this information to better understand a patient's risk profile, but genetic findings should always be interpreted within the context of a comprehensive medical evaluation.
Population Frequency
The rs121908076 variant is considered rare in the general population. According to data from the Genome Aggregation Database (gnomAD), the minor allele frequency is less than 0.0001. This rarity means that the variant is not commonly found in the general public, and its presence is typically investigated in the context of individuals or families presenting with clinical symptoms of hypercholesterolemia.
Managing Genetic Information
If you have received information regarding this variant, it is essential to discuss the findings with a qualified healthcare provider or a genetic counselor. Genetic testing results are complex and should never be used to self-diagnose or make independent medical decisions. A clinician can help interpret what this variant means for your specific health history and determine if further screening or management strategies are appropriate. If you are currently taking medications to manage cholesterol, do not alter your treatment plan without consulting your doctor or pharmacist. They are the best resources for understanding how your genetic profile might interact with your overall health strategy and for providing guidance on evidence-based care.
How common is this variant?
The rs121908076 variant is rare, with a minor allele frequency of less than 0.0001 in the gnomAD database.
Frequently asked questions
What is familial hypercholesterolemia?
Familial hypercholesterolemia is a genetic disorder that causes high levels of LDL cholesterol in the blood from birth. It increases the risk of developing cardiovascular disease at a younger age.
Does having this variant mean I have high cholesterol?
Not necessarily. While this variant is associated with a higher risk of elevated cholesterol, genetic factors are only one part of the picture. You should consult a doctor to have your actual cholesterol levels measured.
Can I change my genetics?
No, you cannot change your DNA. However, knowing your genetic risk can help you and your doctor make informed decisions about lifestyle choices and medical treatments to manage your health.
Should I get tested for this variant?
Genetic testing is typically recommended by a doctor if there is a strong family history of early heart disease or high cholesterol. Discuss the necessity of testing with a healthcare professional.
Sources & further reading
Educational information only, last refreshed 10/11/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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This variant in the LDLR gene is associated with an increased risk of familial hypercholesterolemia.
This variant in the LDLR gene is associated with hypercholesterolemia.
This variant is a pathogenic mutation in the LDLR gene associated with familial hypercholesterolemia.
This pathogenic variant in the LDLR gene is a novel contributor to familial hypercholesterolemia, leading to significantly elevated LDL cholesterol levels.
This mutation is associated with familial hypercholesterolemia, leading to significantly elevated LDL cholesterol levels.
Causes high cholesterol from birth (Familial Hypercholesterolemia).