LDLR rs121918408: Understanding Familial Hypercholesterolemia Variants
The rs121918408 variant is a genetic change located within the LDLR gene. It is recognized in clinical databases as a pathogenic variant associated with familial hypercholesterolemia, a condition characterized by high levels of low-density lipoprotein (LDL) cholesterol.
What each genotype means
Typical LDLR gene profile
This genotype represents the most common sequence found in the general population for this specific location in the LDLR gene. It is not associated with the pathogenic changes linked to familial hypercholesterolemia at this site. Individuals with this profile do not carry the specific variant identified in clinical databases as a potential driver of elevated cholesterol levels.
This is the most common genotype observed across all global populations.
Pathogenic variant carrier
This genotype includes one copy of the variant identified in clinical databases as pathogenic for familial hypercholesterolemia. Carrying this variant is associated with an increased risk of elevated LDL cholesterol levels and potential cardiovascular health implications. Please discuss these results with your clinician or a genetic counselor to understand your personal health context and appropriate screening.
This genotype is extremely rare, appearing in a very small fraction of the population across all ancestries.
Pathogenic variant homozygous
This genotype indicates that both copies of the LDLR gene carry this specific pathogenic variant. This state is associated with a significantly higher risk of severe familial hypercholesterolemia and early-onset cardiovascular disease compared to the general population. It is essential to consult with a healthcare provider or lipid specialist to discuss clinical management and cardiovascular risk assessment.
This genotype is exceptionally rare and has not been widely documented in general population databases.
What is the rs121918408 Variant?
The rs121918408 variant is a specific alteration in the DNA sequence of the LDLR gene. In genetics, a variant is a permanent change in the DNA sequence that makes up a gene. This particular variant is categorized as pathogenic in clinical databases, meaning it is associated with an increased risk of developing a specific health condition. It is important to note that genetic variants are common and occur naturally throughout the human genome. When a variant is identified as pathogenic, it typically means that the change in the DNA sequence may disrupt the normal function of the protein that the gene is responsible for creating. Researchers use databases like ClinVar to track these variants and assess their clinical significance based on available scientific evidence.
The Role of the LDLR Gene
The LDLR gene provides the essential instructions for the body to produce the low-density lipoprotein receptor protein. This receptor plays a critical role in cholesterol metabolism by helping to remove LDL cholesterol—often referred to as 'bad' cholesterol—from the bloodstream. By binding to LDL particles and bringing them into cells, the receptor helps maintain healthy cholesterol levels in the blood. When the LDLR gene contains a pathogenic variant, the resulting receptor may be missing, reduced in number, or unable to function correctly. This impairment prevents the efficient clearance of LDL cholesterol from the blood, which can lead to the elevated cholesterol levels observed in individuals with familial hypercholesterolemia.
Research and Clinical Evidence
Scientific research has established a link between pathogenic variants in the LDLR gene and familial hypercholesterolemia. The evidence for such variants is often derived from clinical studies, family co-segregation analysis, and functional assays that measure how well the mutated receptor performs compared to the normal version. The Clinical Genome Resource (ClinGen) provides expert-curated guidelines to help classify these variants accurately, ensuring that clinical interpretations are based on robust data. While rs121918408 is annotated as pathogenic, the strength of evidence for any specific variant can vary based on the amount of data available. Researchers continue to study these variants to better understand how they influence cholesterol levels and cardiovascular health across different populations.
What This Information Means for You
If you have received information about this variant, it is important to understand that genetic findings are only one piece of a larger health puzzle. This information should never be used to self-diagnose or make medical decisions. Because familial hypercholesterolemia is a complex condition influenced by both genetics and lifestyle factors, you should discuss any genetic test results with a qualified healthcare provider or a genetic counselor. They can help interpret what these findings mean in the context of your personal and family medical history. If you are concerned about your cholesterol levels or cardiovascular risk, your clinician can order appropriate blood tests and provide guidance on management strategies, such as diet, exercise, or medication, tailored to your specific needs.
How common is this variant?
The rs121918408 variant is considered rare in the general population. Specific frequency data can vary significantly by ancestry and is best reviewed through large-scale genomic databases like gnomAD.
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 an earlier age if left untreated.
Does having this variant mean I have high cholesterol?
Not necessarily. While this variant is associated with the condition, genetic testing is not a substitute for clinical blood tests. You should consult a doctor to have your actual cholesterol levels measured.
Can I change my genetics?
No, you cannot change your genetic sequence. However, knowing your genetic risk factors can help you and your healthcare provider create a personalized plan to manage your health through lifestyle changes and medical interventions.
Where can I find more information about LDLR variants?
You can explore resources like ClinVar, MedlinePlus Genetics, and the Clinical Genome Resource (ClinGen) for authoritative information on gene variants and their clinical significance.
Sources & further reading
Educational information only, last refreshed 10/8/2026. 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.