CASR rs193922425: What Your Genotype Means
The rs193922425 variant is a specific change in the CASR gene, which provides instructions for the calcium-sensing receptor protein. This receptor acts as a biological thermostat for blood calcium levels, and variations in this gene are associated with inherited disorders of calcium metabolism.
What each genotype means
Common reference genotype
This is the most common genotype observed in the general population for this location in the CASR gene. It is considered the reference sequence and is not associated with the specific clinical conditions linked to this variant.
This is the most frequently occurring genotype across all major global populations.
Potential clinical significance
This genotype has been identified in clinical databases in association with familial hypocalciuric hypercalcemia. Because this is a rare variant, you should discuss these findings with a healthcare provider or genetic counselor to understand if this result is relevant to your personal health history.
This genotype is extremely rare and is not typically found in the general population.
Potential clinical significance
This genotype has been identified in clinical databases in association with familial hypocalciuric hypercalcemia. Because this is a rare variant, you should discuss these findings with a healthcare provider or genetic counselor to understand if this result is relevant to your personal health history.
This genotype is extremely rare and is not typically found in the general population.
Carrier of rare variant
This genotype indicates you carry one copy of a rare variant that has been linked to familial hypocalciuric hypercalcemia in clinical literature. Please consult with a medical professional to determine if this finding has any clinical implications for you or your family.
This genotype is very rare in the general population.
Carrier of rare variant
This genotype indicates you carry one copy of a rare variant that has been linked to familial hypocalciuric hypercalcemia in clinical literature. Please consult with a medical professional to determine if this finding has any clinical implications for you or your family.
This genotype is very rare in the general population.
Understanding the CASR Gene
The CASR gene encodes the calcium-sensing receptor (CaSR), a protein primarily found in the parathyroid glands and the kidneys. The CaSR protein functions as a G-protein-coupled receptor that constantly monitors the concentration of calcium ions in the extracellular fluid. When it detects calcium, it triggers signaling pathways that help maintain mineral ion homeostasis—the delicate balance of calcium required for normal body function. In the parathyroid glands, the activation of CaSR by blood calcium inhibits the release of parathyroid hormone (PTH). In the kidneys, CaSR helps regulate how much calcium is reabsorbed back into the blood versus how much is excreted in urine. Because of these critical roles, the CaSR protein acts as a master regulator of mineral metabolism. When the gene is altered, the body's ability to sense calcium and respond appropriately can be disrupted, potentially leading to conditions where calcium levels are either too high or too low.
Research and Statistical Associations
Genetic research has linked variants within the CASR gene to several distinct clinical conditions, including Familial Hypocalciuric Hypercalcemia (FHH) and Autosomal Dominant Hypocalcemia (ADH). Scientific literature categorizes CASR variants based on their functional impact: loss-of-function variants often lead to FHH, while gain-of-function variants are typically associated with ADH. The rs193922425 variant is recognized in clinical databases as a marker to be investigated in the context of these calcium-related disorders. Evidence for specific variants in CASR is generally considered moderate to strong when they are found to segregate with these phenotypes in families. However, it is important to understand that the presence of a variant does not guarantee a clinical diagnosis. Population-based studies observe these variants across different groups, and the clinical expression of a CASR variant can vary significantly even among individuals with the same genotype due to other genetic and environmental factors.
Interpreting Your Genetic Information
Information about your CASR genotype should be viewed as educational data rather than a medical diagnosis. Genetic variants are only one piece of the health puzzle. If you have concerns about your calcium levels, bone health, or a family history of metabolic disorders, it is essential to consult with a healthcare provider or a genetic counselor. They can help you interpret this information in the context of your overall health, clinical symptoms, and medical history. You can bring any genetic reports to your physician to discuss whether testing for calcium levels, such as serum ionized calcium or PTH levels, is appropriate for you. Additionally, review your family medical history for recurrent kidney stones, osteoporosis at a young age, or known parathyroid conditions. Do not use this information to self-diagnose or initiate treatments, and if you have symptoms such as chronic fatigue or muscle cramps, seek professional medical evaluation regardless of your genetic results.
How common is this variant?
The prevalence of CASR variants like rs193922425 is generally very low in the general population. According to large-scale genomic databases like gnomAD, these variants are typically rare, reflecting their association with specific, non-common hereditary conditions.
Frequently asked questions
Does having a CASR variant mean I have a disease?
No. Having a genetic variant in CASR does not automatically mean you have a disease. Many people carry rare variants without ever developing the clinical conditions associated with them, as other factors often contribute to how a gene affects health.
What are the symptoms of calcium-related disorders?
Symptoms can vary widely but may include kidney stones, bone pain, fatigue, weakness, or muscle cramps. Often, individuals with these conditions may be asymptomatic and only identified through routine blood tests showing abnormal calcium levels.
How is a CASR-related condition diagnosed?
Diagnosis is typically made by a physician through blood tests that measure calcium, parathyroid hormone (PTH), and sometimes urine calcium levels. Genetic testing may be used to confirm a suspected diagnosis, but it is not the primary way these conditions are identified.
Should I change my calcium intake based on this result?
No. You should never alter your diet or supplement intake based on a genetic report without the direct guidance of a doctor or a registered dietitian. Excess or insufficient calcium can have serious health consequences.
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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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 associated with altered calcium-sensing receptor sensitivity and regulation of parathyroid hormone secretion.
Pathogenic missense variant causing familial hypocalciuric hypercalcemia type 1 (FHH1).
Variant in the CASR gene associated with the calcium-sensing receptor protein.