The NF1 gene helps keep cell growth under control, especially in nerves, skin, and the brain. When it does not work properly, growth signals can stay on too long, causing neurofibromatosis type 1, with features such as café au lait spots, freckling in skin folds, lumps along nerves, and sometimes learning or bone problems. Understanding this gene can help make sense of why signs can vary a lot from one person to another, even within the same family. Public awareness has also grown through advocacy by actor Adam Pearson, who has neurofibromatosis.
What is a gene?
Genes are stretches of DNA that carry instructions your cells use to make molecules or manage processes in the body. Some genes hold the information needed to produce proteins, the parts of cells that do the work. Other genes mostly help regulate when certain processes happen, where they happen, and how strongly they are carried out. Taken together, genes affect how the body develops and works, and they can influence how you respond to food, stress, or medications. To go into this topic in more detail, you can find more in the LearnHub.
Overview
NF1Gene function
What if the gene works
The NF1 gene makes a protein that helps keep cell growth under control. It is especially important in nerves and other tissues as the body grows and repairs itself.
Risk
What if the gene does not work
Variants in the NF1 gene can cause neurofibromatosis type 1, often with café au lait spots, skin or nerve tumors, and learning or bone problems. Milder and more severe variants can influence when features appear and how extensive they become.
Treatment
What does that mean for your treatment
In people with a pathogenic variant in the NF1 gene, MEK inhibitor treatment can be considered for symptomatic plexiform neurofibromas that cannot be fully removed with surgery. Selumetinib is an established option in children, and mirdametinib is also an approved option for some children and adults. These medicines can help shrink tumors and improve pain, movement, or daily function.
Conditions associated with NF1
Gene function
What if the gene works
Normal growth depends on cells receiving signals and then quieting them at the right time. The NF1 gene helps keep that balance, especially in tissues linked to nerves. Knowing how the NF1 gene works in the body helps explain steady cell growth and everyday cell communication.
The NF1 gene helps cells turn down growth messages after they have been received. It does this by making neurofibromin, a protein that switches off RAS, a key signal that tells cells to grow and divide.
This gene helps keep cell growth, division, and survival signals in balance across many tissues. That steady control supports normal tissue upkeep and routine cell turnover.
Neurofibromin is especially important in nerve cells and in the cells that wrap and support nerves. It helps these cells grow, mature, and communicate with nearby tissues in an orderly way.
What is a variant?
A genetic variant is a minor change in the DNA sequence within a gene. These changes are common and help shape normal human diversity, including differences in appearance, metabolism, and how the body responds to environmental influences. Many variants do not have any noticeable effect and are simply part of natural genetic variation. In some cases, though, a variant can change how a gene functions more significantly and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Variants in the NF1 gene can shorten neurofibromin, destabilize it, or alter critical regions, so the protein cannot effectively dampen RAS signaling (a pathway that tells cells when to grow and divide). Understanding how NF1 gene variants affect neurofibromin helps explain why some changes leave partial activity, while others remove function almost completely. This range from milder to more severe variants can influence the functional impact and, in neurofibromatosis type 1, may also shape how early features appear and how extensive they are.
How variants are linked to conditions
Certain pathogenic variants in the NF1 gene cause neurofibromatosis type 1 and can confirm the diagnosis when test results fit a person’s features. People with NF1 gene variants may also have a higher chance of certain tumors, and women may have a higher breast cancer risk before age 50. Features and health risks can vary a lot from one person to another, even within the same family.
A variant is not necessarily a diagnosis
Genetic variants are a common and expected part of being human. Most do not directly affect health and instead reflect normal variation across people. For many genes, a variant associated with a condition points to a possible link rather than a certain diagnosis, particularly when several genes and environmental influences play a part. In other situations, one well understood variant in a particular gene is enough to confirm a diagnosis.
Are there things that can increase or change my risk?
For people with a disease-causing NF1 change, the chance of having NF1 is mostly set by the gene itself, and there is not enough evidence to say lifestyle changes lower that chance. Some genetic changes, such as loss of the whole NF1 gene, are linked with a higher chance of more severe features, and puberty or pregnancy can make some growths increase in size or number. Regular checkups help find problems early.
Inheritance of NF1 variants
NF1-related conditions are inherited in an autosomal dominant pattern, which means a child only needs one altered copy of the NF1 gene to have the condition. If a parent carries a disease-causing variant in the NF1 gene, each pregnancy has a 50% chance of passing it on. When explaining how NF1 gene variants are inherited, it is also important to know that many cases happen because of a new (de novo) variant, so the affected person is the first in the family to have it. People of any sex can inherit or pass on an NF1 variant.
What does my NF1 result mean for my family?
A disease-causing change in the NF1 gene usually means close family members, especially parents, brothers, sisters, and children, could also have the same gene change. Each child of someone with an NF1-related condition has a 1 in 2 chance of inheriting it. NF1 can also happen for the first time in a child, so a parent does not always have it.
Genetic information
Genetic testing
How you find out about variants
Genetic testing for the NF1 gene looks for variants in a blood or saliva sample when doctors want to confirm neurofibromatosis type 1 or clarify a family finding. The lab reads the gene’s DNA code and also checks for missing or extra pieces, because both kinds of changes can matter.
When should I consider getting a genetic test?
Consider NF1 genetic testing if you or your child has signs of neurofibromatosis type 1, such as several light-brown skin patches, freckles in the armpits or groin, growths along nerves, or a close family history of the condition. Testing can help confirm the diagnosis, especially in young children or when the signs are not yet clear.
A genetic result is only one part of your health story
A genetic result can provide valuable insight, but what it can tell you varies with the condition and the type of variant involved. How the body functions over time is shaped by many factors, including lifestyle, environment, age, and medical history. In some conditions, especially those influenced by many genes, genetic information provides context rather than certainty and is most useful when viewed alongside other parts of care. In other situations, a genetic result can offer a clear answer. In areas such as medication response, genetic results can also help put individual experiences into perspective.
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 responds to it at its target. This helps explain why the same treatment works well for one person, does less for another, or causes more side effects in someone else. These differences are common and are one reason medication response can vary from person to person.
What is Pharmacogenetics?
Pharmacogenetics examines how differences in genes can affect a person’s response to medications. It studies connections between genes and drugs to better explain why the same treatment can 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 help support more informed, individualized treatment decisions. More detail on this topic is available in the LearnHub.
Drugs influenced by the NF1 gene
When should I seek medical advice?
There is no broadly confirmed role for this gene in guiding routine medication choice, so questions about side effects, new symptoms, or any medicine changes are best discussed with your doctor. NF1 changes are being studied in some cancers and in neurofibromatosis care to see whether they affect response to certain targeted treatments, but this is not a standard drug-response guide for most medicines.
History
Throughout history, people have described features that hinted at this gene. In 1882, the German pathologist Friedrich Daniel von Recklinghausen gave one of the first clear medical descriptions of the condition now linked to the NF1 gene, which is why older texts may mention his name. Inheritance patterns were noticed long before the gene was identified. A major step came in 1990, when researchers identified the NF1 gene, helping confirm the genetic basis of neurofibromatosis type 1. From these first observations, research expanded steadily. That discovery became an early landmark in gene mapping and helped shape modern medical genetics.