The PIGT gene helps attach many proteins to the outer surface of cells, which lets cells signal and do everyday jobs. If it does not work properly, those proteins may not stay in place, and this can affect the brain, muscles, and other organs. Certain variants in the PIGT gene can cause a rare inherited condition with developmental delay, seizures, low muscle tone, and sometimes differences in bone or organ development.
What is a gene?
Genes are sections of DNA that give your cells instructions for making molecules or directing processes in the body. Some genes provide the information needed to make proteins, which are the working parts of cells. Other genes mainly regulate when certain processes happen, where they happen, and how strongly they occur. Together, genes affect how the body develops and functions, and they can also influence how you respond to food, stress, or medications. For a more detailed look at this topic, you can find more in the LearnHub.
Overview
PIGTGene function
What if the gene works
The PIGT gene helps attach certain proteins to the outer surface of cells. This allows those proteins to support cell signaling, cell-to-cell contact, and other routine tasks across many tissues.
Risk
What if the gene does not work
Pathogenic variants in the PIGT gene can cause developmental delay, low muscle tone, and seizures, sometimes with changes in facial features, heart, or bones. Effects can range from milder to more severe, influencing when symptoms begin and which features appear.
Treatment
What does that mean for your treatment
No PIGT-specific treatment or drug selection is currently established. If you carry a pathogenic variant in the PIGT gene, care is usually guided by your symptoms rather than by a gene-directed medicine.
Conditions associated with PIGT
Gene function
What if the gene works
Many cells need certain proteins placed on their outer surface so they can send signals, interact with nearby cells, and carry out routine work. The PIGT gene helps with this finishing step. It supports the attachment of a small fat based anchor that keeps selected proteins linked to the cell membrane.
The PIGT gene helps attach certain proteins to the outer surface of cells. It does this by helping add a GPI anchor, a small molecule that acts like a tether to hold the protein in the membrane.
Inside your cells, the PIGT gene takes part in the step that prepares selected proteins for membrane attachment. This is a key part of how the PIGT gene helps proteins attach to the cell surface in a stable, usable way.
Many proteins need the right location to work properly, and the PIGT gene helps guide that placement. When this process runs normally, these proteins can stay at the cell surface and take part in cell communication and other everyday tasks.
What is a variant?
A genetic variant is a small difference in the DNA sequence within a gene. These changes are common and help account for normal human diversity, such as differences in appearance, metabolism, or how the body responds to environmental influences. Many variants do not have any noticeable effect and simply represent natural genetic variation. At times, however, a variant can change 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 PIGT gene can make the protein unstable, block its role in adding a GPI anchor (a cell-surface tag), or stop it from being made at all. This explains how PIGT gene variants affect protein function: fewer proteins stay attached to the cell surface, with effects ranging from partial loss in milder variants to near-complete loss in more severe variants. Greater loss often tracks with earlier and more marked PIGT-related symptoms.
How variants are linked to conditions
Pathogenic variants in the PIGT gene cause a rare inherited condition called multiple congenital anomalies-hypotonia-seizures syndrome 3. This PIGT gene related condition usually begins in infancy and commonly involves developmental delay, low muscle tone, and seizures, with some children also having feeding, vision, hearing, or heart, kidney, or bone differences. Symptoms can vary from person to person, but a confirmed disease-causing variant in both copies of the PIGT gene can establish the diagnosis.
A variant is not necessarily a diagnosis
Variants are a normal feature of human biology and are widely present in the general population. Most have no direct effect on health and simply reflect natural human diversity. For many genes, carrying a variant associated with a condition suggests a possible link rather than a definite diagnosis, especially when several genes and environmental factors also contribute. In some situations, though, 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 PIGT, risk is mainly shaped by inheritance rather than lifestyle. A child is affected when they inherit nonworking copies of the PIGT gene from both parents, so family history and whether both parents are carriers matter most; there is not enough evidence to say everyday habits change this risk.
Inheritance of PIGT variants
PIGT inheritance for the well-established inherited PIGT-related condition is autosomal recessive. This means a child inherits one PIGT variant from each parent, and the parents are usually healthy carriers with one changed copy and one working copy of the gene. When both parents carry a PIGT variant, each pregnancy has a 25% chance of an affected child, a 50% chance of a carrier child, and a 25% chance of a child with neither familial variant. Because the PIGT gene is on chromosome 20, this pattern is the same for boys and girls.
What does my PIGT result mean for my family?
For PIGT, family impact is usually discussed in a recessive pattern. This often means the parents of an affected child are healthy carriers, and brothers or sisters may also be affected or may be carriers. Other relatives, such as aunts, uncles, and cousins, can sometimes be carriers too, so the result may matter beyond one person.
Genetic information
Genetic testing
How you find out about variants
PIGT genetic testing looks for variants in the PIGT gene using a blood sample or saliva. In people with features linked to this condition, testing may include single gene sequencing or a broader epilepsy or developmental gene panel, and results can help confirm whether a disease causing variant is present.
When should I consider getting a genetic test?
You may want to discuss PIGT testing if a child has unexplained seizures, major developmental delays, low muscle tone, or several birth differences, especially when more than one of these happen together. Testing can also help when a close family member has a known PIGT variant or a similar condition.
A genetic result is only one part of your health story
A genetic result can be informative, but what it tells you depends on the condition and the kind of variant involved. Over time, how the body works is also shaped by factors such as lifestyle, environment, age, and medical history. For some conditions, especially those affected by many genes, genetic information offers context rather than certainty and is best understood together with other parts of care. In other situations, a genetic result may give a clear answer. In areas like 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 your body responds to some medicines, so the same treatment may not work the same way for everyone. Small inherited differences can change how a drug is absorbed, broken down, moved through the body, or how strongly it acts where it is meant to work. This is common and can influence how well a medicine helps or how sensitive someone is to side effects.
What is Pharmacogenetics?
Pharmacogenetics examines how inherited genetic differences affect the way people respond to medicines. It studies links between genes and medications to understand why the same treatment can work differently in different individuals. With many drugs, genes can influence either how strongly a medicine works or how the body handles it. This information can support treatment choices that are more informed and more personalized. To explore this subject in greater detail, you can find more in the LearnHub.
Drugs influenced by the PIGT gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding medication response, so questions about medicines, side effects, seizures, or other health concerns are best discussed with your doctor.