CASR rs193922439: Understanding Calcium-Sensing Receptor Variants
The rs193922439 variant is located within the CASR gene, which encodes the calcium-sensing receptor protein. This receptor is essential for maintaining calcium homeostasis by regulating parathyroid hormone secretion and urinary calcium excretion.
What each genotype means
Typical calcium sensing
This genotype represents the common, ancestral version of the CASR gene at this position. Individuals with this profile are expected to have standard calcium-sensing receptor function, which is essential for maintaining normal blood calcium levels and parathyroid hormone regulation.
This is the most common genotype observed in the general population across most ancestral groups.
Potential altered receptor sensitivity
This genotype indicates the presence of one copy of the variant allele, which has been associated with familial hypocalciuric hypercalcemia in clinical databases. Because this condition can influence how your body regulates calcium, you should discuss any relevant blood test results or symptoms with your healthcare provider.
This heterozygous genotype is relatively rare and is found at low frequencies in global population databases.
Increased clinical monitoring recommended
This genotype involves two copies of the variant allele, which is documented in clinical literature as having a probable pathogenic association with familial hypocalciuric hypercalcemia. This condition affects the body's ability to sense calcium levels, and individuals with this profile should consult with a medical professional to understand its clinical implications for their health.
This homozygous genotype is very rare in the general population.
What is the CASR Gene?
The CASR gene provides the instructions for creating the calcium-sensing receptor (CaSR) protein. This protein acts as a sensor on the surface of cells, particularly those in the parathyroid glands and the kidneys. By detecting small changes in the concentration of ionized calcium in the blood, the CaSR protein helps the body maintain calcium levels within a very narrow, healthy range. When calcium levels are high, the receptor signals the parathyroid glands to reduce the production of parathyroid hormone (PTH), which in turn helps lower blood calcium levels. Conversely, when calcium levels are low, the receptor allows for increased PTH secretion to help restore balance. Because of its central role in mineral metabolism, variations in the CASR gene can potentially alter how the body senses and responds to calcium, which may influence overall mineral homeostasis.
Understanding the rs193922439 Variant
The rs193922439 variant is a specific single nucleotide polymorphism (SNP) found within the CASR gene. In genomics, a SNP represents a variation at a single position in the DNA sequence. While many variants in the human genome are neutral, those occurring in functional genes like CASR are of particular interest to researchers because they may affect the structure or expression of the resulting protein. The rs193922439 variant is categorized under health predispositions, as research into CASR variants often focuses on their association with altered receptor sensitivity. When a receptor's sensitivity is changed, it can lead to a 'resetting' of the body's calcium set-point, potentially resulting in clinical conditions characterized by either abnormally high or low blood calcium levels. Scientists study these variants to better understand the genetic architecture of mineral metabolism and the underlying causes of related endocrine disorders.
Research and Clinical Associations
Current research into CASR variants, including those similar to rs193922439, highlights their role in calcium-related disorders. Gain-of-function variants in CASR are known to cause autosomal dominant hypocalcemia, a condition where the receptor is overly sensitive to calcium, leading to suppressed parathyroid hormone levels and lower-than-normal blood calcium. Conversely, loss-of-function variants can lead to conditions like familial hypocalciuric hypercalcemia. The evidence strength for many specific CASR variants is considered moderate, as the clinical impact can vary significantly depending on the specific nature of the genetic change and the individual's overall genetic background. It is important to note that while statistical associations exist between certain CASR genotypes and calcium levels, these findings are used in research settings to understand biological mechanisms rather than as diagnostic tools for individuals. Clinical diagnosis of calcium disorders relies on comprehensive blood work and professional medical evaluation.
Population Frequency and Interpretation
The frequency of the rs193922439 variant varies across different human populations. Genetic databases like gnomAD provide data on how often specific alleles appear in diverse ancestral groups, which is crucial for understanding the prevalence of a variant. Because allele frequencies can differ significantly between populations, a variant that is rare in one group might be more common in another. When interpreting genetic information, it is essential to recognize that the presence of a variant does not guarantee a specific health outcome. Many factors, including diet, lifestyle, and other genetic modifiers, contribute to how the body regulates calcium. Readers should view this information as educational rather than diagnostic. If you have concerns about your calcium levels or family history of endocrine disorders, it is recommended that you consult with a healthcare provider or a genetic counselor who can interpret your results in the context of your personal health history.
How common is this variant?
The frequency of rs193922439 varies by population; please consult the gnomAD database for the most current allele frequency data specific to your ancestral background.
Frequently asked questions
What does the CASR gene do?
The CASR gene provides instructions for making the calcium-sensing receptor, which helps the body monitor and regulate blood calcium levels.
Is rs193922439 a diagnostic marker?
No, this variant is not a diagnostic marker. It is a genetic association studied by researchers to understand how variations in the CASR gene may influence calcium metabolism.
Can I use this information to change my diet?
You should not make changes to your diet or supplement intake based on this genetic information. Always discuss your nutritional needs and any health concerns with a qualified healthcare professional.
Where can I find more information about my specific genotype?
You can look up your specific variant in databases like ClinVar or gnomAD. For personal health implications, consult a genetic counselor or your primary care physician.
Sources & further reading
Educational information only, last refreshed 9/15/2026. Not medical advice — these associations describe population statistics, not individual predictions.
Curious what your genotype is for rs193922439?
Upload a raw DNA file from 23andMe, AncestryDNA, MyHeritage, or FamilyTreeDNA and see this variant — plus thousands more — interpreted in your full report.
Get my report — $29Related variants in CASR
Variant in the CASR gene, which encodes the calcium-sensing receptor critical for systemic calcium homeostasis.
Variants in CASR are associated with calcium homeostasis disorders, including familial hypocalciuric hypercalcemia and autosomal dominant hypocalcemia.
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 the calcium-sensing receptor protein.