KCNJ2 rs104894585: Understanding This Genetic Variant
The rs104894585 variant is a specific genetic change located within the KCNJ2 gene. It is primarily studied for its association with Andersen-Tawil syndrome, a rare condition affecting heart rhythm and muscle function.
What each genotype means
Common reference genotype
This is the most frequently observed genotype for this position in the KCNJ2 gene. It is generally considered the baseline or reference state in population studies.
This is the most common genotype found across global populations.
Heterozygous variant carrier
You carry one copy of the reference allele and one copy of the G variant. Research into this specific variant is ongoing, and its clinical significance is currently being evaluated in the context of conditions like Andersen-Tawil syndrome.
This genotype is observed at lower frequencies than the homozygous reference state.
Homozygous variant carrier
You carry two copies of the G variant. This variant has been associated with clinical reports of Andersen-Tawil syndrome and congenital long QT syndrome in some databases, though the penetrance and expressivity can vary significantly between individuals.
This genotype is rare in the general population compared to the reference genotype.
Heterozygous variant carrier
You carry one copy of the reference allele and one copy of the T variant. This variant is documented in clinical databases, and its potential role in phenotypic variation is currently under investigation.
This genotype is observed at lower frequencies than the homozygous reference state.
Homozygous variant carrier
You carry two copies of the T variant. This variant is listed in clinical databases in association with conditions such as Andersen-Tawil syndrome, though further research is required to fully understand its clinical implications for your specific health profile.
This genotype is rare in the general population.
What is the rs104894585 Variant?
The rs104894585 variant is a single nucleotide polymorphism (SNP) located on chromosome 17 within the KCNJ2 gene. In genetics, a SNP represents a variation at a single position in the DNA sequence among individuals. This specific variant is categorized as a pathogenic mutation in clinical databases, meaning it is associated with specific health conditions. It is not a common polymorphism found in the general population; rather, it is identified in clinical settings when investigating individuals who present with symptoms related to channelopathies. Because it is a rare variant, it is not typically found in standard consumer genetic testing reports that focus on common ancestry or wellness traits. Its presence is usually confirmed through targeted clinical sequencing when a healthcare provider suspects a specific genetic syndrome.
The Role of the KCNJ2 Gene
The KCNJ2 gene provides the instructions for creating a protein known as Kir2.1, which is a type of inward-rectifier potassium channel. These channels act like gates in the cell membrane, allowing positively charged potassium ions to flow out of cells. This movement of ions is essential for maintaining the electrical stability of cells, particularly in the heart and skeletal muscles. In the heart, these channels help regulate the rhythm by assisting in the recharging phase after each heartbeat. In skeletal muscles, they are involved in the processes of contraction and relaxation. When the KCNJ2 gene is altered, the resulting potassium channels may not function correctly, which can disrupt the electrical signals necessary for normal muscle and heart activity. This disruption is the underlying mechanism for the symptoms observed in conditions linked to this gene.
Research and Clinical Associations
Research has strongly associated variants in the KCNJ2 gene, including rs104894585, with Andersen-Tawil syndrome (ATS), also known as ATS type 1. This condition is characterized by a triad of symptoms: periodic muscle weakness, cardiac arrhythmias, and certain physical features such as a distinct facial structure or skeletal anomalies. The evidence for this association is considered robust in clinical literature, as the variant has been identified in affected family members in various studies. Because this variant alters the function of the Kir2.1 channel, it can lead to the electrical instability seen in the heart and muscles of those with the syndrome. It is important to note that the severity and specific symptoms can vary significantly even among individuals with the same genetic variant, a phenomenon known as variable expressivity. Clinical diagnosis relies on a combination of genetic testing and a thorough evaluation of physical symptoms.
Understanding Your Results
If you have received information about this variant, it is essential to understand that this is a clinical finding, not a general wellness trait. This variant is not a common genetic marker used for predicting typical physical appearance or common health predispositions. If you are concerned about your results, you should consult with a medical geneticist or a cardiologist who specializes in channelopathies. They can provide context based on your personal and family medical history. You cannot use this information to self-diagnose or make decisions about medications. Any management of heart rhythm or muscle-related symptoms must be directed by a qualified clinician. Genetic information is complex, and professional interpretation is necessary to determine if a variant is relevant to your specific health status or if it requires any clinical follow-up.
How common is this variant?
The rs104894585 variant is rare and is not considered a common polymorphism in the general population, as it is typically absent from large-scale population databases.
Frequently asked questions
Is rs104894585 a common genetic variant?
No, this variant is not common. It is a rare, pathogenic variant that is typically only identified in clinical settings when investigating specific genetic conditions.
What is Andersen-Tawil syndrome?
Andersen-Tawil syndrome is a rare genetic disorder that affects the heart's electrical system, muscle function, and physical development. It is often caused by mutations in the KCNJ2 gene.
Can I use this information to diagnose myself?
No. Genetic variants must be interpreted by a medical professional in the context of your physical symptoms and family history. Never use genetic data to self-diagnose.
What should I do if I have this variant?
If you have been identified as a carrier of this variant, you should discuss the findings with a cardiologist or a genetic counselor. They can help you understand the clinical implications and determine if any monitoring is necessary.
Sources & further reading
Educational information only, last refreshed 9/19/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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