The PC gene gives your body instructions for an enzyme that helps turn food into energy and helps make glucose, especially for the brain and liver. If this gene does not work properly, lactate can build up and the body may struggle to meet its energy needs, sometimes causing too much acid in the blood. People with pathogenic variants in the PC gene can develop pyruvate carboxylase deficiency, which may lead to poor feeding, low muscle tone, developmental delay, seizures, and repeated episodes of illness.
What is a gene?
Genes are stretches of DNA that carry instructions your cells use to make molecules or regulate processes in the body. Some genes hold the directions for making proteins, the functional parts of cells. Others mainly help determine when certain processes happen, where they occur, and how active they are. Together, genes affect how the body develops and works, and they can influence how you respond to food, stress, or medications. To explore this topic in more detail, you can learn more in the LearnHub.
Overview
PCGene function
What if the gene works
The PC gene helps cells turn food into usable fuel. Its protein supports blood sugar balance during fasting and helps make fats and certain brain chemicals.
Risk
What if the gene does not work
Variants in the PC gene can cause pyruvate carboxylase deficiency, which affects energy production and often leads to lactic acid buildup, poor growth, developmental delay, and neurologic problems. Effects range from milder forms to severe early infant illness.
Treatment
What does that mean for your treatment
No PC-specific treatment or drug selection approach is currently established for pathogenic loss-of-function variants in the PC gene. Research is exploring metabolic support strategies, including anaplerotic therapy such as triheptanoin, but these approaches are not yet standard care.
Conditions associated with PC
Gene function
What if the gene works
Your cells use the PC gene to turn pyruvate, a product of food breakdown, into oxaloacetate, a helper molecule used to release energy and make glucose. This step takes place in mitochondria, the parts of cells that release usable energy. It helps explain how the PC gene supports energy production and blood sugar balance.
One of the main jobs of the PC gene is to help the liver and kidneys make glucose between meals. It does this by creating oxaloacetate, a key starting material for this process.
The oxaloacetate made through the PC gene helps refill the cell’s main energy cycle. This keeps energy production running steadily as cells use nutrients for fuel.
Oxaloacetate also gives cells raw material to make certain amino acids, which are the building blocks of protein. This supports routine growth and day to day cell upkeep across many tissues.
What is a variant?
A genetic variant is a minor change in a gene’s DNA sequence. These changes are common in people and help shape normal human diversity, including differences in appearance, metabolism, and the way the body responds to environmental influences. Many do not cause any noticeable effects and are simply part of natural genetic variation. Sometimes, though, a variant changes how a gene works to a greater extent and can contribute to or lead to a genetic condition.
Genetic variants
What if the gene does not work
Changes in the PC gene can leave cells with less pyruvate carboxylase or a protein that folds poorly, is unstable, or has low enzyme activity. This helps explain how PC gene variants affect pyruvate carboxylase function, ranging from milder missense variants that leave some activity to more severe stop, splice, or deletion variants that sharply reduce it. In pyruvate carboxylase deficiency, that activity range often influences how early features appear and how severe they may be.
How variants are linked to conditions
Pathogenic variants in the PC gene are linked mainly to pyruvate carboxylase deficiency, a rare inherited condition. PC gene variants linked to pyruvate carboxylase deficiency can confirm the diagnosis when disease causing variants are present in both gene copies. People with this condition may have low energy, feeding problems, developmental delay, seizures, and episodes of high acid levels in the blood. Severity varies widely from person to person.
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 indicates a possible link rather than a certain diagnosis, especially when several genes and environmental factors play a role. 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?
For PC, risk is mainly set by the genetic change itself rather than lifestyle. A child is affected only if both copies of the PC gene are not working, so risk is higher when both parents are carriers. In people living with PC-related illness, fasting and infections can make symptoms worse, but they do not cause the gene change.
Inheritance of PC variants
PC gene variants linked to pyruvate carboxylase deficiency are inherited in an autosomal recessive pattern. This means a person usually develops the condition only when they inherit one altered copy of the PC gene from each parent. Parents who each carry one variant are often unaffected carriers, and with each pregnancy they have a 25% chance of having a child with the condition. In practical terms, how PC gene variants are inherited means boys and girls are affected at similar rates because the PC gene is on a numbered chromosome, not a sex chromosome.
What does my PC result mean for my family?
For families with a disease-causing change in the PC gene, the pattern is usually recessive, which means parents are often healthy carriers. Brothers and sisters may also be affected or may be carriers, and other close relatives may carry the same change without knowing it. This can matter for future pregnancies and for relatives who want to understand their own chances of having a child with PC-related illness.
Genetic information
Genetic testing
How you find out about variants
To look for changes in the PC gene, a genetic test reads DNA from a blood sample, saliva, or cheek swab and checks for variants linked to pyruvate carboxylase deficiency. PC genetic testing can help confirm the diagnosis, show whether someone carries a family variant, and support family planning.
When should I consider getting a genetic test?
Consider genetic testing for the PC gene if a baby or child has signs of pyruvate carboxylase deficiency, a rare condition that can cause poor feeding, low muscle tone, seizures, or repeated episodes of dangerous acid buildup in the blood. Testing can also help when there is a known family history of this condition.
A genetic result is only one part of your health story
Genetic results can provide useful insight, yet how much they reveal varies with the condition and the kind of variant involved. How the body works over time is also shaped by many factors, including age, environment, lifestyle, and medical history. For some conditions, especially those influenced by many genes, genetic information offers context rather than certainty and is most useful when considered alongside other parts of care. In other situations, a genetic result can give a clear answer. In areas like medication response, these results can also help place personal experiences in context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how your body responds to medicines, so the same treatment may work well for one person but less well for another. These differences can change how quickly a drug is broken down, how much of it reaches its target, or how sensitive the body is to its effects. This is a common part of normal human variation and can influence both how well a medicine works and the chance of unwanted side effects.
What is Pharmacogenetics?
Pharmacogenetics looks at how genetic differences can shape a person’s response to medications. It studies the relationship between genes and drugs to help explain why the same treatment may work differently from one person to another. For many medicines, genes affect either how strongly a drug works or how the body processes it. This information can support more informed, individualized treatment decisions. You can read more about this topic in the LearnHub.
Drugs influenced by the PC gene
When should I seek medical advice?
There is not yet a broadly confirmed role for changes in this gene in guiding medication choice or dose, so questions about medicines, side effects, or new symptoms are best discussed with your doctor.
History
Research on the PC gene grew out of mid 20th century studies of a key metabolic enzyme called pyruvate carboxylase. Scientists first identified the enzyme in the 1960s while mapping how the body handles energy and makes important building blocks. Building on this early work, scientists uncovered more about the gene and linked inherited PC variants to pyruvate carboxylase deficiency, a rare metabolic condition described in later decades. As DNA testing improved, the PC gene was mapped and sequenced, making it possible to confirm the diagnosis at the genetic level. Over time, descriptions became more precise, and researchers recognized that different PC variants can lead to a range of clinical presentations. Today, the PC gene is mainly known in medical genetics through this rare but well established condition.