The IGF1R gene helps cells respond to a major growth signal in the body called insulin like growth factor 1, which supports normal growth before birth and during childhood. Some differences in this gene can reduce how strongly that signal is received. If that happens, a person may be smaller than expected for their family, with short stature, a smaller head size, or mild learning and developmental differences.
What is a gene?
Genes are stretches of DNA that give your cells instructions for building molecules or regulating processes in the body. Some carry the information needed to make proteins, the parts of cells that do the work. Others mainly help control when certain processes occur, where they occur, and how strongly they run. Together, genes influence how the body develops and functions, and they can shape how you respond to food, stress, or medications. For a deeper look at this topic, you can learn more in the LearnHub.
Overview
IGF1RGene function
What if the gene works
The IGF1R gene helps cells respond to a natural growth signal called insulin-like growth factor 1. This supports normal growth before and after birth and helps many tissues develop and repair themselves.
Risk
What if the gene does not work
When the IGF1R gene works less well, growth before and after birth can be reduced, often causing short stature and a smaller head size. Milder to more severe variants can shape when these features appear and how marked they are.
Treatment
What does that mean for your treatment
No IGF1R-specific treatment or management approach is currently established for people with pathogenic variants in the IGF1R gene. The IGF1R gene is also being studied as a cancer drug target and biomarker, but this has not led to routine gene-directed care for inherited IGF1R-related conditions.
Conditions associated with IGF1R
Gene function
What if the gene works
Growth in the body depends on cells sending and receiving clear messages. The IGF1R gene provides instructions for a cell surface protein that receives important growth signals. When this pathway works as expected, it helps coordinate normal development, everyday cell growth, and tissue maintenance.
Cells use the IGF1R protein on their surface to receive insulin-like growth factor signals. This changes outside growth messages into instructions the cell can act on.
These signals help guide normal growth before birth, during childhood, and in ongoing tissue upkeep. This is part of how the IGF1R gene supports normal growth and cell signaling across the body.
IGF1R signaling helps cells grow in a controlled way and build the proteins they need. It also helps coordinate when cells prepare to divide.
Signals through IGF1R help healthy cells stay active during routine wear and tear. This supports steady function in many organs and tissues.
What is a variant?
A genetic variant is a slight 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 do not have any noticeable effect and simply represent natural genetic variation. In some cases, however, 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
Variants in the IGF1R gene can change the receptor’s shape, stability, or movement to the cell surface, so cells respond less to growth signals. This is how IGF1R gene variants affect growth signaling at the cellular level. Milder variants may only partly reduce signaling, while more severe variants can greatly lower receptor activity. That range can influence how marked growth restriction is and when it becomes noticeable.
How variants are linked to conditions
Pathogenic variants in the IGF1R gene are linked to short stature, growth restriction before and after birth, and often a smaller than average head size. This pattern is often described as IGF1 resistance, and a confirmed pathogenic variant can support or establish the diagnosis. Some people also have feeding difficulties, delayed development, or learning differences.
A variant is not necessarily a diagnosis
Variants in genes are a usual feature of human biology and are widely found across the population. Most do not directly affect health and instead reflect normal human variation. For many genes, having a variant connected with a condition points to a potential association, not a definite diagnosis, particularly when several genes and environmental influences also play a role. Still, in certain 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?
There is not yet broadly confirmed evidence on specific factors that increase or reduce health risk related to the IGF1R gene itself. For many living with an IGF1R change, overall health, growth, and development are shaped by the exact gene change and other genes and life factors working together.
Inheritance of IGF1R variants
IGF1R gene variants linked to growth related conditions are most often inherited in an autosomal dominant pattern. This means a child can inherit the variant from either parent, and each child of a parent who carries the variant has a 50% chance of inheriting it. In plain terms, the IGF1R gene inheritance pattern does not depend on whether the parent is the mother or the father. Families can still see differences in how strongly the condition affects each person.
What does my IGF1R result mean for my family?
For IGF1R, a result linked to a growth condition is usually inherited in a dominant way, which means close relatives such as a parent, brother, sister, or child may also carry the same change. In many families, others with the variant have a similar pattern of being smaller than expected before birth and having ongoing short stature. Some IGF1R changes happen for the first time in one person, so a parent does not always have to carry it.
Genetic information
Genetic testing
How you find out about variants
To find out whether you carry a change in the IGF1R gene, doctors use genetic testing for IGF1R variants on a blood sample or saliva swab. A lab reads the gene’s DNA code, often as part of a panel of genes linked to growth, and reports whether a variant is known to affect health, appears harmless, or is still uncertain.
When should I consider getting a genetic test?
Consider testing the IGF1R gene if there is unexplained poor growth, especially when a child was small at birth and stays shorter than expected, or if several relatives have similar growth patterns. Testing can help clarify whether a change in IGF1R is contributing to a growth condition.
A genetic result is only one part of your health story
Genetic test findings can provide useful insight, but what they reveal depends on the condition and the kind of variant involved. Many other factors, including lifestyle, environment, age, and medical history, also influence how the body functions over time. For some conditions, especially those shaped by many genes, genetic information offers context rather than certainty and is best considered together with other parts of care. In other situations, a genetic result may give a clear answer. In areas like medication response, these 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 medicines. Some people break down a drug more slowly or more quickly, while others may be more or less sensitive to its effects. This helps explain why the same treatment works well for one person but not as well for another. These differences are common and can influence both how well a medicine works and the chance of side effects.
What is Pharmacogenetics?
Pharmacogenetics examines how differences in a person’s genes can affect their response to medicines. By studying links between genes and drugs, it helps explain why the same treatment may work differently in different people. With many medications, genes can influence both how powerful a drug’s effects are and how the body handles it. This information can support treatment choices that are better informed and more tailored to the individual. More detailed information about this topic is available in the LearnHub.
Drugs influenced by the IGF1R gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding routine medication choices, so questions about side effects, treatment response, or everyday health concerns are best discussed with your doctor. Research on the IGF1R gene has looked at how some cancers respond to drugs that target this growth pathway, but this has not become standard prescribing guidance.
History
Research on the IGF1R gene grew out of efforts in the late 20th century to understand how the body responds to growth signals. In recent decades, awareness of this gene’s role has grown as scientists separated it from the closely related insulin receptor and mapped it to chromosome 15. During the 1980s and 1990s, cloning and sequencing studies helped show that changes in the IGF1R gene could be linked to differences in growth before and after birth. From these first observations, research expanded steadily into child growth conditions and later into cancer biology. Over time, descriptions became more precise as genetic testing connected specific IGF1R variants with recognizable clinical patterns. These historical steps shaped today’s understanding.