The KL gene helps control how your body handles phosphate, calcium, and vitamin D, mainly through the kidneys, and it also supports cell signals linked to healthy aging. If this gene does not work properly, phosphate can build up and calcium may be deposited in the wrong places, which can cause hard lumps in soft tissues and other problems with mineral balance. Public interest in this gene grew because “klotho” comes from Greek mythology and is linked with life span. Research in animals also made it well known in conversations about aging.
What is a gene?
A gene is a section of DNA that carries instructions your cells use to make molecules or regulate processes in the body. Some genes provide the directions for producing proteins, which are the active components of cells. Others mainly help decide when certain processes happen, where they take place, and how strongly they are carried out. Taken together, genes affect how the body grows and works, and they can also influence how you respond to food, stress, or medications. For a deeper look at this topic, you can find more in the LearnHub.
Overview
KLGene function
What if the gene works
Your cells rely on the KL gene to help control phosphate and vitamin D balance. Its protein works with a hormone called FGF23, helping the kidneys keep mineral levels in a healthy range.
Risk
What if the gene does not work
More disruptive variants in the KL gene can cause hyperphosphatemic familial tumoral calcinosis, with high phosphate levels and calcium deposits in soft tissues, blood vessels, or joints. Milder variants may have smaller effects.
Treatment
What does that mean for your treatment
No KL-specific treatment or management approach is currently established for people with a pathogenic or loss-of-function variant in the KL gene. The KL gene is being studied as a biomarker and possible drug target in kidney disease, phosphate balance conditions, and age-related conditions.
Conditions associated with KL
Gene function
What if the gene works
Your kidneys use the KL gene to keep key minerals in balance. Its protein, called klotho, works mainly as a partner for a body signal called FGF23. Together, they fine tune phosphate and vitamin D levels, which supports healthy bones and other everyday body functions.
Klotho sits on the surface of certain cells and helps them respond to FGF23, a body signal that guides mineral balance. This signaling is especially important in the kidneys, where much of the body’s fine tuning happens.
One of the main jobs of the KL gene is helping the kidneys adjust how much phosphate they keep or release into urine. This supports the normal phosphate balance that bones, teeth, muscles, and cells use every day.
KL also helps the FGF23 signal adjust the active form of vitamin D so mineral absorption stays in balance. This is a central part of how the KL gene helps control phosphate and vitamin D in the kidneys.
What is a variant?
Within a gene, a genetic variant is a small difference in the DNA sequence. These differences are common and are part of normal human diversity, including variation in appearance, metabolism, and the way the body responds to environmental influences. Many variants have no noticeable effect and simply represent natural genetic variation. Sometimes, though, a variant changes how a gene functions more substantially and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Variants in the KL gene can change how the klotho protein folds, reaches the cell surface, is released into its soluble form, or connects with partner proteins, which can weaken cell signaling. These KL gene variant effects on protein function range from milder changes that leave some activity intact to more severe variants that greatly reduce or stop protein stability or signaling. In general, the greater the loss of function, the stronger the downstream cellular impact may be.
How variants are linked to conditions
Rare pathogenic variants in the KL gene cause hyperphosphatemic familial tumoral calcinosis, with high phosphate levels in the blood and calcium deposits in soft tissues, often near joints. In research on how KL gene variants are linked to conditions, this rare inherited illness has the strongest support. Common KL gene changes have also been studied in aging and kidney or heart health, but they do not by themselves diagnose a specific condition.
A variant is not necessarily a diagnosis
Genetic variants are a routine part of human biology and are widely present in the general population. Most do not have a direct effect on health and instead represent normal human diversity. For many genes, carrying a variant associated with a condition suggests a possible link rather than a definite diagnosis, especially when multiple genes and environmental factors are involved. In some situations, however, a single well-characterized variant in a specific gene is enough to confirm a diagnosis.
Are there things that can increase or change my risk?
There is not yet broadly confirmed evidence on specific factors that increase or reduce health risk related to the KL gene. Changes in this gene may influence tendencies linked to aging, kidney health, or heart health, but overall risk is also shaped by many other genes, age, and everyday health factors.
Inheritance of KL variants
For the rare condition most clearly linked to the KL gene, the inheritance pattern for KL gene variants is autosomal recessive. This means a person usually inherits one altered copy from each parent. Parents who each carry one KL gene variant are often unaffected themselves, but with each pregnancy there is a 25% chance their child will inherit both altered copies, a 50% chance the child will be a carrier, and a 25% chance the child will inherit neither altered copy. Sons and daughters are affected at the same rate.
What does my KL result mean for my family?
For families with a disease-causing KL result linked to tumoral calcinosis, relatives can sometimes carry the same gene change even if they do not have symptoms. Brothers and sisters may also be affected or be carriers, and parents are often healthy carriers. Other close relatives may want to learn whether the same result runs in the family.
Genetic information
Genetic testing
How you find out about variants
Genetic testing for KL gene variants usually uses a blood or saliva sample. A lab reads your DNA to see whether a variant is present, and the result can help show whether the KL gene may be linked to your health findings.
When should I consider getting a genetic test?
There is not yet a broadly established KL-specific medical reason for genetic testing. Decisions about testing are best made with a doctor or genetic counselor, based on your health history, family history, and the reason testing is being considered.
A genetic result is only one part of your health story
A genetic result can provide useful insight, but what it can tell you varies based on the condition and the type of variant involved. Many factors, including lifestyle, environment, age, and medical history, also influence how the body functions over time. For some conditions, especially those shaped by many genes, genetic information provides context rather than certainty and is most helpful when viewed alongside other parts of care. In other situations, a genetic result may offer a clear answer. In areas like response to medications, genetic results can help put personal experiences into context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how your body handles certain medicines, so the same treatment may work differently from one person to another. These inherited differences can change how quickly a drug is processed, how strongly it acts, or how likely side effects are. This kind of variation is common and helps explain why medication response is often individual rather than one size fits all.
What is Pharmacogenetics?
Pharmacogenetics is the area of medicine that examines how genetic differences affect the way people respond to medications. It studies links between genes and drugs to help explain why the same treatment can work differently from one person to another. With many medicines, genes can influence both how strongly a drug works and how the body handles it. This information can support treatment decisions that are better informed and more individualized. More detail on this topic is available in the LearnHub.
Drugs influenced by the KL gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding medication choice or dose. If you have concerns about side effects, how well a medicine is working, or possible gene-related health issues, it is best to discuss them with your doctor or pharmacist.
History
The KL gene entered aging research in 1997, when scientists described mice with a shortened lifespan and features that resembled accelerated aging. They named it after Clotho, the figure from Greek mythology associated with the thread of life, which helped make the discovery memorable. Initially understood only through visible traits, later recognized as tied to a specific gene, it quickly became part of broader studies on aging, kidney health, and mineral balance. Building on this early work, scientists uncovered more about the KL gene in both animals and humans. Over time, it became a well-known example of how one gene can shape major ideas in biology. Its history helped spark wider interest in the genetics of aging.