The IGF1 gene helps make a growth signal that supports normal growth of bones, muscles, and many other tissues from before birth through adulthood. If it does not work properly, a person may have poor growth before and after birth, short stature, a small head size, and sometimes developmental or hearing problems. What this gene does can influence how your body builds and repairs tissue throughout life. Variants in the IGF1 gene are uncommon, and their effects can range from mild to more pronounced depending on the specific change.
What is a gene?
A gene is a section of DNA that carries instructions your cells use to make molecules or to regulate processes throughout the body. Some genes provide the directions for building proteins, which are the parts of cells that do much of the work. Others are used mainly to control when certain processes happen, where they happen, and how active they are. Taken together, genes affect how the body grows and works, and they can influence how you respond to food, stress, or medicines. To go deeper into this topic, you can find more in the LearnHub.
Overview
IGF1Gene function
What if the gene works
The IGF1 gene helps your body make a growth signal that supports childhood growth, bone and muscle development, and tissue repair. It also helps cells use nutrients and respond to growth hormone.
Risk
What if the gene does not work
Variants in the IGF1 gene can lead to poor growth before and after birth, causing short stature and a small head size. Milder to severe variants may affect hearing and learning, with symptoms ranging from subtle to noticeable.
Treatment
What does that mean for your treatment
Pathogenic variants in the IGF1 gene can make growth hormone treatment less helpful because the body cannot produce enough IGF-1 in response. In this setting, recombinant IGF-1 replacement with mecasermin is the established treatment approach and can support growth, with dosing and monitoring tailored by a specialist.
Conditions associated with IGF1
Gene function
What if the gene works
Healthy growth depends in part on steady signals from the IGF1 gene. It helps your body make IGF-1, a protein that carries growth messages between cells. Understanding what the IGF1 gene does helps explain how bones, muscles, and many other tissues grow and renew in a balanced way.
The IGF1 gene helps your body make IGF-1, a protein that carries growth messages between cells. These signals support normal growth in childhood and steady tissue renewal through adult life.
IGF-1 helps growth plates and bone-building cells shape and strengthen bone. When this pathway works normally, bones can lengthen during childhood and keep their structure over time.
IGF-1 encourages muscle cells to use nutrients and build protein, which helps muscles grow and stay strong. It also supports normal muscle upkeep after everyday movement and exercise.
Across many tissues, IGF-1 supports controlled cell growth and helps cells stay active and resilient. This steady signaling helps organs develop in an orderly way and maintain routine renewal.
What is a variant?
A genetic variant is a minor change in a gene’s DNA sequence. These changes are common and help shape normal differences among people, such as appearance, metabolism, or the way the body responds to environmental influences. Many variants do not have any noticeable effect and are simply part of normal genetic variation. Sometimes, though, a variant changes how a gene works to a greater extent and may contribute to or lead to a genetic condition.
Genetic variants
What if the gene does not work
Variants in the IGF1 gene can reduce how much IGF-1 protein is made, disrupt its processing, or weaken how well it signals through its receptor. This helps explain how IGF1 gene variants affect growth. Milder variants may leave some activity, while more severe loss-of-function variants can greatly lower signaling. That spectrum often influences how early growth changes appear and how marked they are.
How variants are linked to conditions
Rare harmful variants in the IGF1 gene can cause a rare condition marked by growth restriction before and after birth, short stature, a smaller head size, and sometimes hearing loss or developmental delay. This is one of the clearest IGF1 gene variants and short stature links described in human genetics. Some common variants in the IGF1 gene have also been associated with small differences in adult height, but these do not determine height on their own.
A variant is not necessarily a diagnosis
Genetic variants are a usual part of human biology and are widely seen 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 multiple genes and environmental factors also play a role. In some situations, though, a single well characterized variant in a specific gene can be 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 clearly increase or reduce health risk related to the IGF1 gene itself. Personal risk usually depends on the exact gene change, family history, and other health and lifestyle factors, so a doctor or genetic counselor can help put results in context.
Inheritance of IGF1 variants
For the main well-established IGF1-related condition, the IGF1 gene inheritance pattern is autosomal recessive. This means a child inherits one altered copy of the IGF1 gene from each parent, and parents who carry one copy are usually unaffected. When both parents carry an IGF1 gene variant, each pregnancy has a 25% chance of resulting in a child with the condition, a 50% chance of producing a carrier child, and a 25% chance of producing a child with two typical copies. Because IGF1 is on chromosome 12, this pattern is the same for boys and girls.
What does my IGF1 result mean for my family?
For families with a disease-causing IGF1 result linked to the recognized growth condition, the pattern is usually recessive, which means parents are often healthy carriers. Brothers and sisters may also be affected or may be carriers, and other close relatives could carry the same gene change without knowing it. This can matter for family planning and for understanding unexplained poor growth in the family.
Genetic information
Genetic testing
How you find out about variants
To look for changes in the IGF1 gene, genetic testing uses a blood or saliva sample to read your DNA. IGF1 genetic testing can show whether you carry a variant linked to certain growth related conditions, but the result still needs clinical interpretation because some variants do not fully explain a person’s symptoms.
When should I consider getting a genetic test?
Genetic testing for the IGF1 gene may be considered when a child has very poor growth starting before birth and continuing after birth, especially along with a small head size, hearing loss, or developmental delays. It can also help when a rare inherited growth condition runs in the family.
A genetic result is only one part of your health story
Genetic results can be informative, but how much they explain varies based on the condition and the specific type of variant. 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 offers context rather than certainty and is best considered alongside 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 place personal experiences into context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines. Two people taking the same treatment may absorb, break down, or respond to it differently because inherited gene changes can influence how the body handles a drug and how strongly the drug acts on its target. This kind of variation is common and can help explain why a medicine works well for one person, works less well for another, or causes more side effects in some people.
What is Pharmacogenetics?
Pharmacogenetics looks at how genetic variation can shape the way a person responds to medication. It studies the relationship between genes and drugs to help explain why the same treatment can work differently from one person to another. For many medicines, genes affect how the body processes a drug or how strongly that drug works. This understanding can support treatment decisions that are more informed and more individualized. More on this topic is available in the LearnHub.
Drugs influenced by the IGF1 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding medication choices, so questions about side effects, treatment response, or new symptoms are best discussed with your doctor. Some research has looked at IGF1 and how people respond to growth hormone treatment, but this is not used as a standard guide for most medicines.
History
Across cultures and time periods, inherited patterns were noted in growth and body size, long before scientists could connect them to a specific gene. In the mid 20th century, researchers studying growth hormone found that some of its effects were carried out by a separate blood signal, first called somatomedin. By the 1970s and 1980s, this signal was identified more clearly as insulin like growth factor 1, linking earlier hormone research to the IGF1 gene. From these first observations, research expanded steadily. Work on the IGF1 gene helped shape modern understanding of childhood growth, rare growth conditions, and the biology of aging. Its history is closely tied to major advances in endocrinology, the field that studies hormones.