The NANS gene helps make sialic acid, a sugar your body uses to build and maintain many tissues, especially the brain and bones. This gene plays an important role in early growth and development. If both copies do not work properly, the body may make too little sialic acid, which can lead to developmental delay, intellectual disability, short stature, and changes in bone shape. NANS is a rare gene and is not widely known outside genetics and rare disease care.
What is a gene?
Genes are stretches of DNA that hold instructions your cells use to make molecules or regulate activities in the body. Some provide the code for proteins, which do much of the cell’s work. Others mainly guide when certain activities happen, where they take place, and how active they are. Taken together, genes affect how the body develops and works, and they can also shape how you respond to food, stress, or medications. More on this topic is available in the LearnHub.
Overview
NANSGene function
What if the gene works
The NANS gene helps your body make sialic acid, a sugar used on cell surfaces. This supports brain development, growth, and communication between cells.
Risk
What if the gene does not work
Variants in the NANS gene can cause developmental delay, short stature, and skeletal differences, sometimes with brain development changes. Effects range from milder to more severe, which can influence when features appear and how marked they are.
Treatment
What does that mean for your treatment
No treatment or drug choice specific to pathogenic variants in the NANS gene is currently established in clinical guidelines. Research is exploring whether replacing missing pathway products, such as with N-acetylmannosamine, might help in NANS deficiency, but this remains investigational.
Conditions associated with NANS
Gene function
What if the gene works
Your cells need the NANS gene to make sialic acid, a sugar used to finish many proteins and fats on the cell surface. This finishing step helps cells interact in an orderly way and supports routine growth and signaling. Understanding how the NANS gene works can make it easier to see how cells build and maintain their outer coating.
The NANS gene helps cells make sialic acid, a sugar used on many cell surface molecules. Its protein combines smaller parts to form an early version that cells can then finish and use.
By supplying sialic acid, the NANS gene supports the sugar coating placed on many proteins and fats. This is part of glycosylation (adding sugars to molecules), which helps cell surfaces stay stable and work smoothly.
Those surface sugars help cells send signals, recognize nearby cells, and interact in a controlled way. Through this support role, the NANS gene contributes to everyday communication across many tissues.
What is a variant?
A genetic variant is a small alteration in the DNA sequence of a gene. These changes are common and are part of normal human diversity, such as differences in appearance, metabolism, or how the body responds to environmental influences. Many variants have no noticeable effect and simply represent natural genetic variation. In some cases, though, a variant can change the function of a gene more substantially and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
NANS gene variants can change the enzyme’s shape or make it unstable, so cells produce less of a sugar building block needed to finish many proteins and cell surfaces. Milder NANS gene variants may leave some enzyme activity, while more severe variants, such as those that cut the protein short or disrupt how the gene message is pieced together, can leave very little or none. In NANS-related conditions, less activity often goes along with earlier onset and more marked features.
How variants are linked to conditions
NANS gene variants are linked to a rare inherited condition that affects growth and development, often called NANS-congenital disorder of glycosylation. People with this condition may have developmental delay, intellectual disability, short stature, and differences in bone growth, and some also have low muscle tone, movement problems, or vision changes. It usually appears when both copies of the gene carry a pathogenic variant.
A variant is not necessarily a diagnosis
Genetic variants are a usual part of human biology and are widely found across the general population. Most do not directly affect health and simply reflect normal human diversity. For many genes, having a variant associated with a condition points to a potential link rather than a certain diagnosis, particularly when several genes and environmental influences play a role. In some situations, though, one well-studied variant in a particular 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 risk related to the NANS gene. For many living with a NANS-related condition, risk is mainly shaped by the specific gene change inherited in the family, and personal questions about risk are best discussed with a doctor or genetic counselor.
Inheritance of NANS variants
NANS-related conditions are inherited in an autosomal recessive pattern, which explains how NANS gene variants are inherited in families. This means a child usually needs to inherit one altered copy of the NANS gene from each parent to be affected. Parents who each carry one variant are often unaffected themselves, and with each pregnancy they have a 25% chance of having an affected child, a 50% chance of having a child who is a carrier, and a 25% chance of having a child with no familial variant.
What does my NANS result mean for my family?
For families with a disease-causing NANS result linked to NANS-related developmental condition, close relatives may also carry the same gene change. Brothers and sisters may be affected or be carriers, and parents are often healthy carriers. Other relatives, such as aunts, uncles, and cousins, may also carry the variant, so the result can be relevant across the family.
Genetic information
Genetic testing
How you find out about variants
Genetic testing for variants in the NANS gene usually uses a blood or saliva sample. A lab reads the gene's DNA code, often with sequencing, and may also look for missing pieces of the gene. Results may identify a benign variant, a variant linked to disease, or a finding that remains uncertain.
When should I consider getting a genetic test?
Testing for changes in the NANS gene may be considered when a child has unexplained developmental delay, short stature, or bone growth changes, especially if similar features run in the family. It can also help when a relative already has a confirmed NANS variant and you want to clarify family risk.
A genetic result is only one part of your health story
Genetic results can be informative, but how much they clarify depends on the condition and the kind of variant involved. Many other factors, including lifestyle, environment, age, and medical history, also shape how the body functions over time. For some conditions, especially those influenced by many genes, genetic information offers context rather than certainty and is best understood along 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 people respond to medicines. Small differences in genes can change how the body breaks down a drug, moves it through the bloodstream, or reacts to it at its target. Because of this, the same medication may work better for some people, have less effect in others, or cause more side effects in someone who is more sensitive to it.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences can affect the way people respond to medications. It focuses on 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 can influence how strongly a drug works or how the body processes it. This information can support more informed and individualized treatment decisions. You can learn more about this topic in the LearnHub.
Drugs influenced by the NANS 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 questions about treatment, side effects, or other health concerns are best discussed with your doctor. Seek medical advice if symptoms are new, getting worse, or affecting daily life.
History
The NANS gene entered medical genetics relatively recently, after researchers first studied the body pathway it belongs to and later connected that pathway to an inherited condition. Initially understood only through visible traits, later recognized as tied to a specific gene, NANS gained clearer clinical importance when affected families were described in the medical literature in the 2010s. From these first observations, research expanded steadily, linking changes in the NANS gene with a pattern of developmental and bone growth features. As medical science evolved, so did understanding of this gene, moving from basic biochemical research to more precise genetic diagnosis.