Growth delay due to insulin-like growth factor type 1 deficiency is a rare condition that mainly affects growth from early childhood. Children with growth delay due to insulin-like growth factor type 1 deficiency are often much shorter than expected for their age, and early signs of growth delay due to insulin-like growth factor type 1 deficiency can include slow height gain over time. Not everyone will have the same experience. Growth delay due to insulin-like growth factor type 1 deficiency is usually long term, and treatment may include regular injections of mecasermin along with close follow-up of growth, nutrition, and overall health. Life expectancy can be normal in many people with growth delay due to insulin-like growth factor type 1 deficiency, but the outlook depends on the cause and whether other health problems are also present.
How many people live with Growth delay due to insulin-like growth factor type 1 deficiency?
This condition is thought to be extremely rare: Orphanet classifies it as affecting fewer than 1 in 1 million people, which suggests fewer than about 8,100 people worldwide (Orphanet, 2023; United Nations, 2024). Using that same rate, an estimated fewer than about 340 people may be living with it in the United States, although that is an estimate rather than a direct count (Orphanet, 2023; U.S. Census Bureau, 2024).
Overview
Growth delay due to insulin-like growth factor type 1 deficiencySymptoms
Growth delay due to insulin-like growth factor type 1 deficiency often causes short height, slow growth in childhood, and a smaller-than-expected head size. Many living with Growth delay due to insulin-like growth factor type 1 deficiency also have delayed puberty and reduced muscle strength.
Outlook and prognosis
Growth delay due to insulin-like growth factor type 1 deficiency often means ongoing short stature, and many living with it need long-term growth and hormone care. Outlook is usually best when treatment starts early, with height gains varying by cause, timing, and overall health.
Causes and risk factors
Growth delay due to insulin-like growth factor type 1 deficiency can result from inherited gene changes or, less often, new genetic changes. Risk is also higher with poor nutrition, chronic liver disease, severe illness, or hormone signaling problems.
Genetic influences
Genetics are very important in Growth delay due to insulin-like growth factor type 1 deficiency, because changes in the IGF1 pathway often drive it. Some genetic variations affect severity, but not everyone has the same change or the same pattern.
Diagnosis
Diagnosis of growth delay due to insulin-like growth factor type 1 deficiency usually starts with growth patterns, exam findings, and blood tests showing very low IGF-1. Doctors may confirm it with genetic tests and, sometimes, imaging or bone age X-rays.
Treatment and drugs
Treatment for growth delay due to insulin-like growth factor type 1 deficiency often includes daily mecasermin injections, careful dose increases, and regular checks of growth and blood sugar. Good nutrition and specialist follow-up also help.
Symptoms
Children with growth delay due to insulin-like growth factor type 1 deficiency are often much smaller than expected for their age, even when day-to-day health otherwise seems typical. This happens because the body does not make enough IGF-1, a growth signal that helps bones and other tissues grow. The changes are often subtle at first, blending into daily life until they become more noticeable. The early features of growth delay due to insulin-like growth factor type 1 deficiency often show up in infancy or early childhood, although the pattern can vary from child to child.
Children are usually much shorter than expected for their age and family pattern. This difference often becomes clearer over time, especially when they are compared with classmates or siblings.
Height increases more slowly than usual, so the growth curve may flatten instead of following the expected path. Families may notice that clothes and shoe sizes change much more slowly than in other children.
Some babies are smaller than expected at birth and continue to grow slowly through infancy and childhood. Not every child has this pattern, but it can be an early clue to the condition.
Some infants and children can have episodes of low blood sugar, especially during illness or after long gaps between meals. This may look like shakiness, sweating, unusual sleepiness, or irritability.
How people usually first notice Growth delay due to insulin-like growth factor type 1 deficiency?
How insulin-like growth factor type 1 deficiency is first noticed often starts with a child who is much shorter than expected for their age, even though they were a normal size at birth. Families and doctors may also notice that growth slows in the first years of life, baby teeth come in late, and some children have a small chin, a prominent forehead, or hands and feet that seem smaller than usual. The first signs of growth delay due to insulin-like growth factor type 1 deficiency are usually picked up during routine growth checks, when a child keeps falling further behind on the growth chart rather than catching up.
Types of Growth delay due to insulin-like growth factor type 1 deficiency
No distinct types of Growth delay due to insulin-like growth factor type 1 deficiency are widely recognized.
Can I slow down the onset of symptoms?
No, there is no good evidence that diet, exercise, sleep, or supplements can meaningfully delay when symptoms begin in growth delay due to insulin-like growth factor type 1 deficiency, because it is mainly caused by an early problem with the body’s growth signal. Healthy habits still support overall health, but they do not prevent this condition or stop growth delay from appearing; if the diagnosis is confirmed, early care from a hormone specialist is important because a medicine that replaces this missing signal can help some children grow better. While treatment cannot promise a normal growth pattern, getting expert care early may help your child get the best support possible.
What genetics can tell you about symptoms
Genetics can sometimes help explain why people with growth delay due to insulin-like growth factor 1 deficiency have different symptoms, even within the same family. Changes in the gene involved can affect how much the body responds to growth signals, which may influence how severe the short stature is, whether growth delay starts early in childhood, and whether other features such as small head size or delayed development are present. Even so, genetics does not always predict the full picture, because symptoms can vary from one person to another.
Causes and risk factors
If a child grows much more slowly than expected, the causes of growth delay due to insulin-like growth factor type 1 deficiency usually involve trouble making IGF-1 or using growth hormone normally. This often happens because of an inherited gene change or a new gene change that affects growth signaling. Some risks are modifiable (things you can change), others are non-modifiable (things you can’t). Poor nutrition and untreated liver, kidney, or thyroid problems can lower IGF-1 further and make slow growth more noticeable. A family history of short stature or related hormone problems can raise the chance, although the severity can vary from child to child.
What are the most common causes or risk factors?
The most common cause of growth delay linked to low IGF-1, a body signal that helps children grow, is a problem in the growth pathway: some children are born with gene changes that make too little IGF-1 or make the body respond poorly to growth hormone, the signal that normally tells the liver to produce IGF-1. Low IGF-1 can also happen without an inherited gene change, most often because of poor nutrition, long-term illness such as liver or kidney disease, or other hormone problems like low thyroid or low growth hormone levels. A family history of short stature or growth disorders can raise the chance in some families, but doctors also look closely for treatable causes such as undernourishment or chronic illness.
Environmental and biological risk factors
Growth delay due to insulin-like growth factor type 1 deficiency can happen when the body does not make enough of this growth signal, or cannot respond to the signals that should raise it. Doctors often group risks into internal (biological) and external (environmental). Knowing the risk factors for growth delay due to insulin-like growth factor type 1 deficiency can help explain why a child is growing more slowly than expected and what doctors may check next.
When the pituitary gland makes too little growth hormone, the liver may not produce enough IGF-1. This is a major biological risk for growth delay due to insulin-like growth factor type 1 deficiency.
Sometimes growth hormone is present, but the body does not respond to it well, so IGF-1 stays low. This can lead to poor height gain even when growth hormone levels are not clearly low.
The liver makes most of the body's IGF-1, so liver disease can lower levels significantly. Ongoing liver problems raise the risk of growth delay due to insulin-like growth factor type 1 deficiency.
Not getting enough calories or protein, severe feeding problems, and poor absorption from the gut can all reduce IGF-1 production. Growth may slow over time when the body does not have the building blocks it needs.
Genetic risk factors
When a child is much shorter than expected for age and keeps falling behind on the growth chart, the reason can sometimes be a gene change that lowers IGF-1, an important growth signal in the body. Some risk factors are inherited through our genes. In growth delay due to insulin-like growth factor type 1 deficiency, the main genetic cause is a harmful change in the IGF1 gene, although a few people have a larger missing piece of DNA that affects this gene. The inherited risk of growth delay due to insulin-like growth factor type 1 deficiency often depends on whether one or both parents carry the same gene change.
IGF1 variants: The best-known genetic cause is a harmful change in the IGF1 gene, which helps the body make IGF-1. If both copies of this gene do not work properly, growth before and after birth can be affected.
DNA deletions: Some people have a larger missing piece of DNA that includes the IGF1 gene. This can lead to low IGF-1 levels and similar growth problems, and sometimes other features if nearby genes are also missing.
Recessive inheritance: This condition is often passed down in an autosomal recessive pattern, which means a child inherits one nonworking copy of IGF1 from each parent. Parents who carry one changed copy usually do not have the full condition.
Family history: Having a brother, sister, or other close relative with the condition can raise the chance of the same gene change being present in a family. A history of marked short stature starting very early in life can be an important clue.
Related parents: When parents are biologically related, they are more likely to carry the same rare gene change. This increases the chance of recessive conditions like growth delay due to insulin-like growth factor type 1 deficiency.
New changes: In rare cases, the gene change or DNA deletion happens for the first time in the child and is not inherited from either parent. When that happens, the chance for future children can differ from families with a clearly inherited change.
Lifestyle risk factors
Lifestyle habits do not cause growth delay due to insulin-like growth factor type 1 deficiency, but they can influence growth support, day-to-day health, and the risk of complications. In practice, how lifestyle affects growth delay due to insulin-like growth factor type 1 deficiency is mostly through nutrition, activity balance, sleep, and treatment routines. The most helpful approach is to focus on habits that support normal growth, bone health, muscle strength, and overall well-being.
Poor calorie, protein, vitamin, and mineral intake can further limit growth and weight gain in a child who already has insulin-like growth factor 1 deficiency. A nutrient-dense eating pattern helps support bone development, muscle growth, and response to medical care.
Skipping meals or having a very irregular eating pattern can make it harder to meet the energy needs required for growth. Regular meals and snacks may help maintain steady nutrition during periods when growth is already vulnerable.
Too little activity can reduce muscle strength, endurance, and bone loading, while excessive training without enough nutrition can work against healthy growth. Age-appropriate exercise supports bone health, physical function, and confidence without causing the condition itself.
Short or disrupted sleep can interfere with normal hormonal rhythms that support growth and recovery. A consistent sleep schedule may help children with this condition make the most of their body's remaining growth potential.
Risk prevention
Growth delay due to insulin-like growth factor type 1 deficiency usually cannot be fully prevented, because it often happens when the body does not make enough IGF-1 or cannot respond to it normally. For many living with growth delay due to insulin-like growth factor type 1 deficiency, prevention is mainly about lowering the chance of complications, supporting growth and nutrition, and finding related health problems early. Prevention is flexible—it adapts to your life and health background.
Regular follow-up with a pediatric hormone specialist can help track height, weight, puberty, and overall health over time. This can make it easier to spot concerns early and adjust care before problems build up.
Good nutrition helps support growth, energy, bone health, and immune function in children with growth delay due to insulin-like growth factor type 1 deficiency. If eating is difficult or weight gain is slow, a dietitian can help plan meals that fit daily life.
Some children with severe IGF-1 deficiency can have low blood sugar, especially during illness or long gaps without food. Preventing long fasts and having a sick-day plan may lower the risk of shakiness, sleepiness, or more serious episodes.
If a doctor recommends IGF-1 treatment, taking it exactly as directed may help support growth and reduce some complications linked to growth delay due to insulin-like growth factor type 1 deficiency. Regular monitoring also helps manage side effects and check whether treatment is helping.
Can you prevent Growth delay due to insulin-like growth factor type 1 deficiency?
Usually, no, this type of growth delay cannot be fully prevented because it often happens when the body cannot make or use an important growth signal properly, sometimes because of genes. Good nutrition and early care for long-term health problems may lower the chance of poor growth in some children, but they do not prevent this condition in every case. Early checkups can still help catch it sooner and support healthy growth as much as possible.
Transmission
Growth delay due to insulin-like growth factor type 1 deficiency is not infectious, so it cannot spread from one person to another through touch, coughing, sex, blood, or shared food. Instead, the genetic transmission of growth delay due to insulin-like growth factor type 1 deficiency usually happens before birth, most often when a child inherits a changed copy of the IGF1 gene from each parent; the parents are often healthy carriers.
In some families, the condition may result from a new genetic change in the child rather than being passed down. If you are trying to understand how growth delay due to insulin-like growth factor type 1 deficiency is inherited in your family, genetic counseling can help clarify the chances for future pregnancies.
When to test your genes
Consider genetic testing when a child has marked short stature or slow growth that starts early, especially with low IGF-1 levels, a family history of similar growth problems, or poor response to growth hormone. Testing can confirm the cause and help guide treatment choices and counseling for relatives.
Diagnosis
Growth delay due to insulin-like growth factor type 1 deficiency is usually suspected when a child is much shorter than expected for age and grows more slowly over time. Doctors often look at growth patterns, body proportions, and overall health first, then confirm the cause with targeted tests. Some conditions have a genetic link, meaning they can run in families, so the diagnosis of growth delay due to insulin-like growth factor type 1 deficiency may also include genetic testing.
Doctors review height, weight, and growth speed over months or years to see whether growth is consistently below the expected range. They also compare measurements with family heights and the timing of puberty, because these can affect how a child grows.
Doctors look for clinical features such as very short stature, body proportions, and signs of other hormone or long-term health problems. This helps show whether the growth delay fits insulin-like growth factor type 1 deficiency or points to another cause.
Blood tests measure insulin-like growth factor 1 and often related hormones, including growth hormone. Thyroid tests and other lab tests may help rule out common conditions that can also slow growth.
If needed, doctors may perform hormone stimulation tests to see how the body releases growth hormone under controlled conditions. This can help tell the difference between low growth hormone and poor response to growth hormone, which matters in how growth delay due to insulin-like growth factor type 1 deficiency is diagnosed.
How is Growth delay due to insulin-like growth factor type 1 deficiency diagnosed?
Growth delay due to insulin-like growth factor type 1 deficiency is usually diagnosed by looking at a child’s growth over time, doing a physical exam, and using blood tests to see whether IGF-1, a body signal that helps growth, is lower than expected. Doctors may also do a hand or wrist X-ray to check bone age and rule out more common reasons for slow growth, such as poor nutrition, thyroid problems, or long-term illness. Genetic testing can help confirm the cause in some families, but it is usually used alongside these other findings rather than on its own.
Stages of Growth delay due to insulin-like growth factor type 1 deficiency
Growth delay due to insulin-like growth factor type 1 deficiency does not have defined progression stages. That is because it is usually identified by a pattern of slow growth over time rather than a set path of worsening phases, and some features may stay fairly stable while height falls further behind expected growth. Often the process begins when you notice changes in daily life, such as a child staying in the same clothing size much longer than classmates or being one of the shortest in class year after year. Doctors usually start with a conversation about growth, family history, and the early symptoms of growth delay due to insulin-like growth factor type 1 deficiency, then use height and weight measurements over time, a physical exam, blood tests, and sometimes genetic testing to confirm the cause and monitor progress.
Outlook and prognosis
The outlook for people with growth delay due to insulin-like growth factor type 1 deficiency varies with the underlying cause, severity, and how early treatment begins. In children with severe primary IGF-1 deficiency, recombinant IGF-1 therapy can improve growth velocity substantially, especially when started young and monitored carefully, although adult height may still remain below average in some cases. Prognosis is generally better when nutrition, other hormone problems, and associated medical conditions are addressed promptly. Lifelong short stature and, in some individuals, ongoing metabolic or developmental issues may occur, particularly in syndromic or genetically complex cases. Mortality is not usually thought to be increased in isolated IGF-1 deficiency itself, but overall survival can be affected when the condition is part of a broader disorder with additional organ involvement.
Long-term effects
For many living with growth delay due to insulin-like growth factor type 1 deficiency, the long-term picture is often shaped by short stature and how other body systems grow over time. Effects can range from mainly height differences to broader health and developmental concerns, depending on the cause and severity. In childhood, some features are easier to notice, while in adulthood the focus may shift to daily function, bone health, and metabolic health.
The most lasting effect is usually shorter adult height, often well below the expected range for the family. Growth delay due to insulin-like growth factor type 1 deficiency can also affect how quickly children grow from year to year.
Many people have proportionate short stature, meaning the body stays in balance but remains smaller overall. In some cases, the head may appear relatively small compared with age expectations, especially when the deficiency is severe from early life.
Some children may have delays in motor skills, learning, or speech, although this varies widely. Early symptoms of growth delay due to insulin-like growth factor type 1 deficiency can include slow growth along with slower developmental progress.
Infants and young children may be more prone to episodes of low blood sugar, which can cause shakiness, sleepiness, poor feeding, or irritability. In more severe cases, repeated episodes can become a longer-term concern if they happen often.
How is it to live with Growth delay due to insulin-like growth factor type 1 deficiency?
Living with growth delay due to insulin-like growth factor 1 deficiency often means being much shorter than peers and sometimes having lower muscle strength or stamina, which can affect sports, school activities, and everyday confidence. For many living with this condition, the emotional side can be just as important as the physical one, especially if they face unwanted attention, teasing, or repeated questions about their size. Family members may spend extra time coordinating medical visits, growth monitoring, and treatment, while also helping build a supportive environment so height does not define the person. With steady care and strong social support, many people with this condition adapt well and lead active, full lives.
Treatment and drugs
Growth delay due to insulin-like growth factor type 1 deficiency is treated by focusing on growth, nutrition, and overall health, usually with care from a pediatric hormone specialist. The main treatment for some children is replacement with a lab-made form of IGF-1, given as regular injections, to help support height gain and steady growth over time. Doctors also watch closely for side effects such as low blood sugar, enlarged tonsils, or headaches, and check growth regularly so treatment can be adjusted as needed. Not every treatment works the same way for every person, and how well it helps can depend on age, how early treatment starts, and the severity of the IGF-1 deficiency. Alongside medical treatment, lifestyle choices play a role, including making sure meals are regular, nutrition is adequate, and any related health concerns are treated promptly.
Can you cure Growth delay due to insulin-like growth factor type 1 deficiency?
No, there is not currently a cure for growth delay caused by very low levels of insulin-like growth factor 1, a body signal that helps children grow. Treatment cannot fully remove the underlying problem, but replacement medicine can help some children grow better, and regular care can help manage feeding, blood sugar, and other health issues that may come with it.
Non-drug treatment
For families living with growth delay due to insulin-like growth factor type 1 deficiency, care often centers on helping a child grow, eat, move, and learn as well as possible in daily life. Non-drug treatments often lay the foundation for tracking growth, supporting nutrition, and addressing any delays in strength, speech, or school skills. Because this condition can affect children in different ways, the plan is usually tailored over time. Some children first come to care when the early symptoms of growth delay due to insulin-like growth factor type 1 deficiency become easier to spot next to peers, such as slower height gain or trouble keeping up physically.
Regular visits with a pediatric endocrinology team help track height, weight, and growth speed over time. This can show whether support is working and whether new concerns need attention.
A dietitian can help build meals and snacks that support steady growth and healthy weight gain. For many, treatment begins not at the pharmacy, but at the table with enough calories, protein, and key nutrients.
Some children have poor appetite, tiring with meals, or oral-motor difficulties that make eating hard. Feeding therapy can help make meals safer, less stressful, and more effective.
Physical therapy can improve strength, balance, posture, and motor skills if a child seems less steady or tires easily. This may help with everyday activities like climbing stairs, playground play, or sports at school.
Your genes may have an impact on how drugs work for you
For people with growth delay due to low insulin-like growth factor 1, genetic differences can affect how well treatment works because the main problem is often in the body’s growth signaling pathway, not just a lack of growth hormone. This means some children may get little or no benefit from standard growth hormone treatment, while many living with this condition respond better to treatment that replaces the missing growth signal directly, such as IGF-1 shots. In day-to-day life, that can mean one child grows more steadily on treatment while another needs a different plan or closer follow-up, even when they seem to have the same condition.
Pharmacological treatments
For many families, the day-to-day issue is slow growth despite otherwise careful care and nutrition. In growth delay due to insulin-like growth factor type 1 deficiency, the main medicine used is mecasermin, a lab-made form of IGF-1 given by injection. Medication can feel like a big step, but this treatment is used to help children who do not make enough usable IGF-1 and therefore do not grow well even when growth hormone signals are present. In true primary IGF-1 deficiency, standard growth hormone treatment is usually not the main treatment because the body cannot respond to it normally.
Mecasermin is the main drug treatment for growth delay due to insulin-like growth factor type 1 deficiency, especially in children with severe primary IGF-1 deficiency. It is given by injection, usually twice a day with food or a meal, to lower the risk of low blood sugar. Over time, it may help improve height growth, although response varies from child to child.
Standard growth hormone medicines such as somatropin usually do not work well when the problem is true IGF-1 deficiency caused by poor response to growth hormone. That is because the body cannot effectively turn the growth signal into enough IGF-1, so doctors generally consider a different treatment for growth delay due to insulin-like growth factor type 1 deficiency.
Mecasermin treatment needs careful follow-up because it can cause low blood sugar, enlarged tonsils or adenoids, headaches, and injection-site reactions in some children. Doctors also watch growth rate, puberty, and symptoms that could suggest raised pressure inside the head or worsening scoliosis. Keep a simple diary of symptoms and side effects to share at follow-up visits.
Genetic influences
For some families affected by growth delay due to insulin-like growth factor type 1 deficiency, rare inherited changes in genes involved in growth are an important part of the cause. Genes are the instructions your body uses to grow and function, and changes in the IGF1 gene itself, or in genes that control growth hormone signals, can leave the body with too little IGF-1 or make it harder to use it properly. This helps explain why some children with growth delay due to insulin-like growth factor type 1 deficiency grow more slowly from early childhood, even with good nutrition. Some cases happen for the first time in one child, while others are seen in several relatives, and the pattern in a family depends on the specific gene involved. Other health problems can also lower IGF-1, so genes are not the only possible explanation. When doctors suspect an inherited cause, family history and genetic testing can help confirm it and guide treatment and counseling.
Is Growth delay due to insulin-like growth factor type 1 deficiency genetic?
Genetics are very important in Growth delay due to insulin-like growth factor type 1 deficiency, because changes in the IGF1 pathway often drive it. Some genetic variations affect severity, but not everyone has the same change or the same pattern.
Having a genetic risk is not necessarily a diagnosis
Changes in genes are a normal part of being human and are common throughout the general population. Most of these changes do not directly affect health and simply reflect natural human variation. For many genes, having a change associated with a condition points to a possible link rather than a certain diagnosis, especially when several genes and environmental factors are involved. In some cases, though, a single well-understood change in a specific gene can be enough to confirm a diagnosis.
Pharmacogenetics—how genetics influence drug effects
For many families, the biggest question is why a child is not growing as expected and why usual treatment may not help. In growth delay due to insulin-like growth factor type 1 deficiency, the exact gene change can affect whether the body makes too little of this growth signal or cannot respond to growth hormone properly, so standard growth hormone treatment may help little or not at all. Not every difference in response is genetic, but genetic testing can help doctors sort out whether treatment for growth delay due to insulin-like growth factor type 1 deficiency is more likely to include insulin-like growth factor 1 replacement instead of more growth hormone. The genetic result can also shape follow-up, including how closely growth is tracked and which side effects, such as low blood sugar, need extra attention. Even with the same genetic finding, children can respond differently, so doctors usually tailor treatment over time based on growth, age, and overall health.
Interactions with other conditions
For many living with growth delay due to insulin-like growth factor type 1 deficiency, the biggest day-to-day issue is that other health problems can make slow growth stand out even more. Doctors often look carefully for conditions such as poor nutrition, celiac disease, thyroid disorders, and long-term kidney, liver, heart, or bowel disease, because these can also limit growth or make treatment response harder to judge. Another important aspect is how it may link with other diseases. In some children, delayed puberty or other hormone problems can add to the picture, so it may not be obvious at first which issue is driving the short stature or other early symptoms of growth delay due to insulin-like growth factor type 1 deficiency. This is why care usually involves more than measuring height alone: blood tests, growth tracking, and review of overall health help doctors tell whether there is one main cause or several working together. When any other illness is found and treated, it can make the child’s growth pattern and treatment plan much clearer.
How genes can cause diseases
Humans have more than 20,000 genes, each carrying out one or a few specific functions in the body. One gene instructs the body to digest lactose from milk, another tells the body how to build strong bones and another prevents the body's cells from beginning to multiply uncontrollably and developing into cancer. As all of these genes combined are the building instructions for our body, a defect in one of these genes can have severe health consequences.
Through decades of genetic research, we know the genetic code of any healthy/functional human gene. We have also identified that in certain positions on a gene, some individuals may have a different genetic letter from the one you have. We call these hotspots "Genetic Variations" or "Variants" in short. In many cases, studies have been able to show that having the genetic letter "G" in the position makes you healthy, but having the letter "A" in the same position disrupts the gene function and causes a disease. Genopedia allows you to view these variants in genes and summarizes all that we know from scientific research, which genetic letters (Genotype) have good or bad consequences on your health or on your traits.
What other conditions can cause similar symptoms to Growth delay due to insulin-like growth factor type 1 deficiency?
Several other conditions can look very similar, especially other causes of slow growth and short height, such as low growth hormone levels, an underactive thyroid, poor nutrition, or long-term health problems like celiac disease, kidney disease, or heart disease. Some children are also small because they were born smaller than expected and do not fully catch up, or because short height runs in the family or puberty starts later than usual. Doctors may also consider certain genetic conditions, such as Turner syndrome in girls, because these can also affect growth.
History
Families and communities once noticed patterns in children who stayed much smaller than expected as they grew, even when they seemed well cared for and did not fit the usual picture of poor nutrition or long-term illness. What we now call growth delay due to insulin-like growth factor type 1 deficiency came into clearer view gradually, as doctors realized that not all causes of short stature were the same. For many living with this condition, the everyday impact can start early: clothes fit for years, classmates shoot up in height, and routine growth checks begin to raise questions.
Early medical reports focused mainly on what could be seen from the outside, especially slow growth in childhood and a final adult height well below average. At first, these cases were often grouped together with other causes of severe short stature, because doctors did not yet have the tools to tell them apart. As hormone testing improved in the second half of the 20th century, researchers began to understand that some children had a specific problem in the body’s growth-signaling pathway, rather than a lack of growth hormone alone.
This shift mattered because it changed how the condition was recognized. Instead of relying only on appearance or height charts, specialists started looking more closely at growth patterns, blood test results, and how the body responds to growth signals. Building on this early work, scientists later identified a genetic cause in some families, which helped explain why the condition can run in relatives and why symptoms may vary from one person to another.
In recent decades, awareness has grown, and growth delay due to insulin-like growth factor type 1 deficiency is now better distinguished from other forms of short stature. That has helped make the early symptoms of growth delay due to insulin-like growth factor type 1 deficiency easier to recognize in children who are not growing as expected. Not every early description was complete, yet together they helped shape today’s approach, which is more precise, more supportive, and better able to guide families through testing, treatment decisions, and long-term care.