CASR rs193922432: Understanding This Calcium-Sensing Variant
The rs193922432 variant is a specific genetic change located within the CASR gene. It is associated with conditions that affect how the body regulates calcium levels, such as familial hypocalciuric hypercalcemia and autosomal dominant hypocalcemia.
What each genotype means
Typical CASR function
This is the common, reference genotype for this position in the CASR gene. It is associated with typical function of the calcium-sensing receptor, which helps regulate blood calcium levels.
This is the most common genotype found in the general population.
Potential CASR variant carrier
You carry one copy of the variant allele, which has been documented in clinical databases in relation to conditions like familial hypocalciuric hypercalcemia. Because this is a heterozygous genotype, its clinical impact can be variable; please consult with a healthcare provider or genetic counselor to understand what this means for your specific health context.
This genotype is rare in the general population.
CASR variant associated profile
You carry two copies of this variant, which is documented in clinical literature as potentially pathogenic. This variant is associated with conditions affecting calcium regulation, such as familial hypocalciuric hypercalcemia or autosomal dominant hypocalcemia. Please discuss these findings with a medical professional to determine if clinical follow-up or calcium level monitoring is appropriate for you.
This genotype is extremely rare in the general population.
What is rs193922432 and Where is it Located?
The variant rs193922432 is a single nucleotide polymorphism (SNP) found on chromosome 3. In the human genome, it is situated within the CASR gene, which provides the blueprint for the calcium-sensing receptor protein. This specific variant involves a change in the DNA sequence that can alter the structure or function of the resulting protein. Because the CASR gene is critical for maintaining the balance of minerals in the blood, changes in its sequence are closely monitored by researchers and clinicians. Genetic databases like dbSNP and ClinVar track this variant to help understand its potential impact on human health. It is classified as a missense variant, meaning the change in the DNA code results in a different amino acid being incorporated into the calcium-sensing receptor protein, which may affect its ability to function correctly within the cell membrane.
The Role of the CASR Gene
The CASR gene encodes the calcium-sensing receptor (CaSR), a protein that acts like a thermostat for calcium levels in the body. This receptor is primarily found in the parathyroid glands and the kidneys. In the parathyroid glands, the CaSR protein detects the concentration of calcium in the blood; when calcium levels are high, the receptor signals the glands to reduce the secretion of parathyroid hormone. In the kidneys, the receptor helps regulate how much calcium is reabsorbed into the bloodstream versus how much is excreted in urine. By constantly monitoring extracellular calcium levels, the CaSR protein ensures that calcium remains within a very narrow, healthy range. This process is essential for normal nerve function, muscle contraction, and bone health. When the CASR gene contains variants that impair this receptor's function, the body's ability to maintain calcium homeostasis can be disrupted.
Research Associations and Evidence Strength
Clinical databases, including ClinVar, have documented rs193922432 in association with several conditions related to calcium regulation. These include familial hypocalciuric hypercalcemia and autosomal dominant hypocalcemia. The evidence for these associations is considered moderate, as clinical reports have linked the presence of this variant to altered calcium levels in affected individuals. Research suggests that the variant may lead to either a loss-of-function or a gain-of-function in the receptor, depending on the specific molecular impact, which in turn dictates whether the body perceives calcium levels as too high or too low. Because clinical presentations can vary significantly between individuals, even those with the same genotype, the evidence is interpreted within the context of a patient's overall clinical history. It is important to note that genetic associations are statistical in nature and do not guarantee the development of a specific medical condition.
Population Frequency
The rs193922432 variant is considered rare in the general population. Frequency data from large-scale genomic projects like gnomAD indicate that this specific allele is not widely distributed across major ancestral groups. Because it is a rare variant, it is not typically found in the majority of the population. When a variant is rare, it is often studied in the context of specific families or clinical cohorts where the associated conditions have been identified. Researchers use these population databases to distinguish between common genetic diversity and rare variants that may have a more significant impact on protein function. If you are interested in your own genetic data, you can check your results against these global frequency metrics to see how your genotype compares to the broader population.
What You Can and Cannot Do With This Information
Information about your genotype for rs193922432 is for educational purposes only and should not be used for self-diagnosis or medical decision-making. Genetic variants are only one piece of a complex puzzle that includes your environment, lifestyle, and other genetic factors. If you have concerns about your calcium levels or a family history of calcium-related disorders, the most important step is to consult with a healthcare professional, such as an endocrinologist or a genetic counselor. They can order appropriate blood tests to measure your actual calcium and parathyroid hormone levels, which provide a much clearer picture of your health than a genetic test alone. Never change your diet, supplements, or medications based on genetic information without direct guidance from your doctor. A clinician can help you interpret these findings in the context of your overall health and determine if any further clinical investigation is necessary.
How common is this variant?
The rs193922432 variant is a rare genetic change with a very low minor allele frequency across global populations in gnomAD.
Frequently asked questions
What does the CASR gene do?
The CASR gene provides instructions for making the calcium-sensing receptor, which helps the body maintain stable calcium levels in the blood.
Is rs193922432 a dangerous mutation?
This variant is associated with conditions affecting calcium regulation, but its clinical impact depends on many factors. It is not a simple 'dangerous' or 'safe' label, and you should discuss any concerns with a doctor.
How do I know if I have this variant?
You can identify your genotype for this variant through clinical genetic testing or direct-to-consumer genetic reports. If you have these results, a genetic counselor can help you understand what they mean for you.
Can I change my CASR gene expression?
You cannot change your underlying DNA sequence. However, medical treatments exist to manage conditions related to calcium levels if they are identified by a healthcare provider.
Should I be worried about my calcium levels?
Genetic variants do not automatically mean you have a health problem. If you are concerned about your calcium levels, ask your doctor for a standard blood test to check your serum calcium and parathyroid hormone levels.
Sources & further reading
Educational information only, last refreshed 9/15/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Variants in CASR are associated with calcium homeostasis disorders, including familial hypocalciuric hypercalcemia and autosomal dominant hypocalcemia.
Variant in the CASR gene associated with the calcium-sensing receptor protein.
Variant in the CASR gene involved in the regulation of the calcium-sensing receptor.
Pathogenic missense variant causing familial hypocalciuric hypercalcemia type 1 (FHH1).
Variant in the CASR gene associated with altered calcium-sensing receptor sensitivity and regulation of parathyroid hormone secretion.