The PIGS gene helps cells attach certain proteins to their outer surface using a small anchor, which many tissues need to work normally. If this gene does not work as it should, some proteins may not reach the cell surface properly, which can disrupt cell signaling, especially in the brain. Pathogenic variants in the PIGS gene are linked to a rare inherited condition that can include developmental delay, seizures, low muscle tone, and feeding difficulties. PIGS is mainly known in clinical genetics rather than popular culture.
What is a gene?
Genes are sections of DNA that hold information cells use to make molecules or direct processes in the body. Some genes carry instructions for making proteins, the parts of cells that do the work. Others mostly regulate when certain processes happen, where they happen, and how strongly they occur. Taken together, genes affect how the body develops and functions, and they can also influence how you respond to food, stress, or medications. To explore this topic in more detail, you can find more in the LearnHub.
Overview
PIGSGene function
What if the gene works
The PIGS gene helps cells attach certain proteins to their outer surface using a small fat-like anchor. This supports cell signaling, immune function, and normal development.
Risk
What if the gene does not work
When the PIGS gene does not work properly, it can cause an inherited condition with developmental delay, seizures, and low muscle tone. Milder and more severe variants can affect when symptoms begin and how strongly they appear.
Treatment
What does that mean for your treatment
No PIGS-specific treatment or management approach is currently established for people with a pathogenic or loss-of-function variant in the PIGS gene.
Gene function
What if the gene works
Many cells need certain proteins to be fastened to their outer surface so they can send signals and interact with nearby cells. The PIGS gene helps with this step in the cell area where proteins are prepared. Knowing how the PIGS gene helps attach proteins to the cell surface makes it easier to understand routine cell function.
The PIGS gene helps a cell machine attach GPI anchors (small fatty tethers) to selected proteins. This fastening step lets those proteins stay on the outside of the cell, where they can do their jobs.
Many proteins need this anchor before they can reach the right place on the cell surface. By helping with this step, the PIGS gene supports how cells signal, interact, and respond to their surroundings.
Inside the endoplasmic reticulum (the cell area where proteins are prepared), the PIGS gene works with partner proteins in the GPI transamidase complex. Together, they recognize proteins meant for surface anchoring and prepare them for attachment.
What is a variant?
A genetic variant is a slight difference in the DNA sequence of a gene. These differences are common and are part of normal human diversity, such as variation in appearance, metabolism, or the way the body responds to environmental influences. Many variants do not have any noticeable effect and simply represent natural genetic variation. In some situations, though, a variant can change a gene’s function more significantly and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Variants in the PIGS gene can reduce or block production of a key part of the GPI anchor, a small molecular tag that attaches certain proteins to the cell surface. This is how variants in the PIGS gene affect cell surface proteins and change how cells communicate. Some variants leave partial activity, while more severe loss-of-function variants may shut the process down almost completely. That difference can influence how early symptoms appear and how broad or pronounced they are.
How variants are linked to conditions
Pathogenic variants in the PIGS gene cause a rare inherited condition often described as a developmental and epileptic encephalopathy. In reports of conditions linked to PIGS gene variants, affected children commonly have developmental delay, low muscle tone, and seizures, with some also showing feeding difficulties, hearing or vision problems, or brain imaging changes. A confirmed disease-causing PIGS variant can establish the genetic diagnosis.
A variant is not necessarily a diagnosis
Genetic variants are a routine part of human biology and are common throughout the general population. Most do not have a direct effect on health and simply reflect natural human variation. For many genes, carrying a variant associated with a condition suggests a possible link rather than a definite diagnosis, especially when more than one gene and environmental influences 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 risks related to the PIGS gene. For families with a known PIGS-related condition, risk is mainly shaped by the gene changes inherited from both parents, rather than by lifestyle or everyday exposures.
Inheritance of PIGS variants
PIGS-related conditions are inherited in an autosomal recessive pattern. This means a person usually develops the condition only when both copies of the PIGS gene carry a disease-causing variant, with one altered copy inherited from each parent. Parents who each carry one PIGS gene variant are often unaffected carriers, and with each pregnancy they have a 25% chance of having an affected child, a 50% chance of having a child who is also a carrier, and a 25% chance of having a child with two working copies. In practical terms, how variants of the PIGS gene are inherited usually involves both parents passing on one altered copy.
What does my PIGS result mean for my family?
For families, a PIGS result is usually most relevant in a recessive pattern, which means parents are often healthy carriers and brothers or sisters may also be carriers or, less often, have the condition. Close relatives may want to learn whether the same gene change runs in the family, especially when there is a history of developmental delay, seizures, or other similar concerns in a child. Future children in the family may also be affected if both parents carry a changed copy of PIGS.
Genetic information
Genetic testing
How you find out about variants
To find out whether you carry a change in this gene, genetic testing for PIGS variants uses DNA from a blood sample or saliva and reads the gene's code. Testing may be done as a single gene test, a broader panel, or exome sequencing, and the lab compares your result with known variants.
When should I consider getting a genetic test?
Testing for changes in the PIGS gene may be considered when a baby or child has unexplained seizures, developmental delay, low muscle tone, or other signs of a rare inherited condition. It can also be helpful when similar problems run in the family or when standard testing has not found a cause.
A genetic result is only one part of your health story
Genetic findings can be informative, but how much they reveal varies depending on the condition and the kind of variant involved. Over time, many other factors also shape how the body works, including lifestyle, environment, age, and medical history. For some conditions, especially those influenced by many genes, genetic information provides context rather than certainty and is most useful when considered alongside other parts of care. In other situations, a genetic result may offer a clear answer. In areas such as medication response, genetic results can also help put individual experiences into context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines. Some people break down or move a drug through the body differently, so the same treatment may work better for one person, have less effect in another, or cause more side effects. These differences are common and are one reason medication response can vary from person to person.
What is Pharmacogenetics?
Pharmacogenetics looks at how differences in genes can affect a person’s response to medication. It examines links between genes and drugs to better understand why the same treatment may work differently from one person to another. For many medicines, genes help shape how strongly a drug works or how the body handles it. This information can support more informed, more individualized treatment decisions. To explore this topic in greater detail, you can learn more in the LearnHub.
Drugs influenced by the PIGS gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in predicting how medicines will work, so general questions about symptoms, side effects, or treatment choices are best discussed with your doctor.