Monosomy 5p is a rare genetic condition that is usually present from birth and often recognized in infancy or early childhood. People with Monosomy 5p may have developmental delay, feeding problems, low muscle tone, and a high-pitched cry in early life, although features can vary. Not everyone will have the same experience. Monosomy 5p is lifelong, and care focuses on speech, physical, and occupational therapy, along with treatment for specific medical needs such as feeding, growth, hearing, or heart concerns. Life expectancy in Monosomy 5p can vary with the severity of associated health problems, but many people live into adulthood with supportive care.
How many people live with Monosomy 5p?
Monosomy 5p is very rare, and exact totals are not directly counted; using Orphanet’s reported range of 1 to 9 people per 100,000, about 80,000 to 730,000 people worldwide may be living with it, although this is only an estimate and the wide range reflects how rare conditions are measured (Orphanet; United Nations population data, 2024). Using that same reported range for the current U.S. population suggests roughly 3,300 to 30,000 people in the United States may be living with monosomy 5p (Orphanet; U.S. Census Bureau population data, 2024).
Overview
Monosomy 5pSymptoms
Monosomy 5p often causes a high-pitched cry in infancy, delayed speech and learning, and low muscle tone. Many with Monosomy 5p also have small head size, feeding difficulties, and distinct facial features.
Outlook and prognosis
Outlook in Monosomy 5p varies widely, but many people benefit from early speech, physical, and learning support. Life expectancy can be near typical in milder cases, while prognosis depends on heart problems, breathing issues, seizures, and the level of developmental disability.
Causes and risk factors
Monosomy 5p happens when part of chromosome 5 is missing, usually as a new genetic change and less often inherited from a parent with a balanced chromosome rearrangement. There are no lifestyle or environmental risk factors.
Genetic influences
Genetics are central to Monosomy 5p, because it is caused by missing genetic material on the short arm of chromosome 5. Genetic variations, especially the size and exact location of the missing segment, can influence how Monosomy 5p affects someone.
Diagnosis
Monosomy 5p is often suspected from clinical features present at birth and early development. The diagnosis of Monosomy 5p is confirmed with genetic tests that show missing genetic material on the short arm of chromosome 5.
Treatment and drugs
Monosomy 5p is treated with supportive, long-term care. Early speech, physical, and occupational therapy can help with feeding, movement, and communication. Some children also need hearing checks, heart care, or surgery for related problems.
Symptoms
From the first months of life, Monosomy 5p can affect feeding, growth, movement, learning, and communication. The early features of Monosomy 5p often become noticeable in infancy or early childhood, although the mix and severity can differ widely. Features vary from person to person and can change over time. Many children also have a recognizable pattern of facial traits and may need extra support with development.
In babies, the cry may sound unusually high-pitched, especially early in life. This often becomes less noticeable with age, so older children may not have this feature.
Many babies have a weak suck, trouble coordinating swallowing, or take a long time to finish feeds. For families, this can mean slow weight gain and extra help with feeding in the first months.
Babies and children may feel floppy or have less strength and stability in the trunk and limbs. This can make head control, sitting, crawling, and walking take longer to develop.
Some children are small at birth or grow more slowly than expected in childhood. Over time, this can lead to shorter height and lower weight than their peers.
How people usually first notice Monosomy 5p?
Monosomy 5p is often first noticed in a newborn because of a very high-pitched, weak cry that can sound unusual, along with low muscle tone, feeding difficulties, and a smaller-than-expected head size. In many living with monosomy 5p, doctors or families also notice slow early development, poor weight gain, or distinct facial features during the first days, weeks, or months of life. Sometimes the first signs of monosomy 5p are picked up even before birth through prenatal testing or ultrasound, but more often it is first recognized after delivery when these early physical and developmental signs appear together.
Types of Monosomy 5p
No distinct types of Monosomy 5p are widely recognized.
Can I slow down the onset of symptoms?
No. Monosomy 5p is caused by a missing piece of genetic material before birth, so there is no proven way to delay when symptoms start, and lifestyle changes do not prevent the condition. What can help is early support, such as feeding help, physical and speech therapy, and regular checks for hearing, vision, growth, and heart problems; these steps can improve day-to-day development and catch treatable issues early, even though they do not stop the condition itself.
What genetics can tell you about symptoms
In monosomy 5p, the symptoms are linked to a missing piece of the short arm of chromosome 5, and the size and exact location of that missing piece can affect which features show up, how severe they are, and sometimes when they are noticed. In general, larger missing segments are more often linked with greater developmental delays, lower muscle tone, feeding problems, and the high-pitched cry seen in early infancy, but there is still a wide range from one child to another. Genetics can give useful clues about the overall pattern, but it usually cannot predict every symptom or exactly how mild or severe life will be for any one person living with monosomy 5p.
Causes and risk factors
When a baby has feeding trouble or delayed development, Monosomy 5p is caused by a missing piece from the short arm of chromosome 5 before birth. Most cases are new genetic changes, but some happen because a parent carries a balanced chromosome change and passes on missing genetic material. The main risk factor is a family history of that chromosome change, so parents may be offered chromosome testing. Lifestyle, diet, stress, and everyday environmental exposures are not known to cause Monosomy 5p, but the size of the missing piece can affect how strongly the condition shows up. Genetic testing can sometimes clarify your personal risk, especially when planning another pregnancy.
What are the most common causes or risk factors?
Monosomy 5p is caused by a missing piece of chromosome 5, and most cases happen by chance when the egg or sperm is formed or very early after conception. In a smaller number of families, it happens because one parent carries a balanced chromosome change, which usually does not cause problems for the parent but can increase the chance of this condition in a child. There are no well-known lifestyle, diet, or pregnancy-related risk factors, so it is not caused by something a parent did or did not do.
Environmental and biological risk factors
Monosomy 5p usually begins with a chromosome change that happens by chance very early in development, so most families have done nothing to cause it. Researchers are still exploring how outside influences interact with our inner biology. For now, the main risk factors for monosomy 5p are biological chromosome events, and clear environmental triggers have not been firmly proven.
The most common biological risk is a chance error when an egg or sperm is forming, causing part of chromosome 5 to be lost. This usually happens spontaneously and cannot be predicted in advance.
In some pregnancies, the missing chromosome piece appears just after fertilization as the first cells divide. These early changes are also random and are not linked to anything most parents could have prevented.
A smaller number of cases are linked to a chromosome rearrangement already present in one parent, which can raise the chance that part of chromosome 5 is missing in a pregnancy. If monosomy 5p has occurred in a family, chromosome testing may help clarify whether this risk is present.
No everyday environmental exposure has been consistently shown to cause monosomy 5p. Factors like routine diet, normal activity, or common stress are not known causes.
Genetic risk factors
Monosomy 5p usually happens when part of the short arm of chromosome 5 is missing. For families wondering about the genetic causes of monosomy 5p, most cases begin as a new change by chance when the egg or sperm forms, rather than being passed down. Some risk factors are inherited through our genes. A smaller number of people with monosomy 5p inherit an unbalanced chromosome change because a parent carries a balanced rearrangement.
New deletion: Most people with monosomy 5p have a new deletion that was not present in either parent. This missing segment usually appears by chance during formation of the egg or sperm, so families often have no prior history of the condition.
Balanced translocation: Sometimes monosomy 5p happens because a parent carries a balanced translocation, meaning chromosome pieces have swapped places without causing symptoms in the parent. This can raise the chance of having a child with an unbalanced loss of 5p, so parent chromosome testing is often advised.
Deletion size: The amount of chromosome 5p that is missing can affect how monosomy 5p shows up. Larger deletions often lead to more developmental and medical concerns, although this is not exact for every child.
Missing genes: Features depend partly on which genes are lost within 5p, not just how much is missing. Loss of certain regions is linked with the classic high-pitched cry, developmental delay, and differences in growth.
Ring chromosome: In a small number of cases, chromosome 5 forms a ring after losing material from its ends. This can cause monosomy 5p and may lead to more variation because ring chromosomes can be less stable as cells divide.
Mosaicism: Some people have mosaic monosomy 5p, which means only some cells carry the missing piece of chromosome 5. This can lead to milder or less typical features, depending on how many cells are affected and which tissues carry the change.
Lifestyle risk factors
Monosomy 5p is present from birth, so lifestyle habits do not cause it. However, how lifestyle affects Monosomy 5p can be important for growth, development, mobility, feeding safety, sleep, and day-to-day functioning. The most relevant lifestyle risk factors for Monosomy 5p are the habits and routines that can worsen symptoms or make complications more likely.
Poor calorie intake or limited food variety can worsen growth delay and low muscle mass in children with Monosomy 5p. Structured meals, texture adjustments, and dietitian guidance may support weight gain and development.
Fast feeding, unsuitable food textures, or poor positioning during meals can raise the risk of choking, coughing, or aspiration in Monosomy 5p. Careful pacing and swallowing strategies may reduce respiratory complications and make feeding safer.
Very low activity can worsen hypotonia, poor coordination, joint stiffness, and delayed motor skills in Monosomy 5p. Regular movement, play, and physical therapy-based exercise may help strength, balance, and functional independence.
Irregular sleep schedules or untreated sleep problems can worsen irritability, attention, learning, and daytime behavior in Monosomy 5p. Consistent bedtime habits and evaluation of snoring or restless sleep may improve daily functioning.
Risk prevention
Monosomy 5p is a genetic condition present from birth, so there is no known way to prevent the condition itself. For many living with monosomy 5p, prevention is mainly about lowering the risk of complications, supporting development, and catching problems early. Prevention is flexible—it adapts to your life and health background. Early, steady care can make day-to-day life easier and may help limit some of the health issues linked to monosomy 5p.
Ongoing visits with a pediatrician and other specialists can help spot feeding, growth, heart, hearing, vision, or spine problems early. Prevention works best when combined with regular check-ups.
Speech, physical, and occupational therapy can support movement, communication, and daily skills from an early age. In monosomy 5p, starting support early may reduce the impact of developmental delays over time.
Some babies and children with monosomy 5p have trouble sucking, swallowing, or gaining weight. Early feeding assessment and nutrition support can help prevent poor growth, dehydration, and chest infections from aspiration.
Keeping up with routine vaccines, good hand hygiene, and prompt care for breathing problems can lower the risk of common infections. This matters because some children with monosomy 5p may be more vulnerable if feeding or airway issues are present.
Can you prevent Monosomy 5p?
Monosomy 5p usually cannot be prevented, because it most often happens by chance when a baby is developing and is caused by a missing piece of chromosome 5. In a smaller number of families, one parent carries a harmless chromosome change that can raise the chance of it happening again, so genetic counseling and chromosome testing before or during pregnancy can help clarify the risk and your options. These steps cannot guarantee prevention, but they can help with planning.
Transmission
Monosomy 5p is a genetic condition, so it is not infectious and cannot be caught from someone through touch, coughing, kissing, sex, food, or shared spaces. For many families asking about how Monosomy 5p is inherited, the key point is that most cases happen as a new genetic change when the egg or sperm is formed, or very early after conception.
Less often, Monosomy 5p can be passed from a parent who carries a balanced chromosome change and may be healthy themselves. If Monosomy 5p is diagnosed in a child, genetic testing of the parents can help clarify the genetic transmission of Monosomy 5p and the chance of it happening again in another pregnancy.
When to test your genes
For monosomy 5p, genetic testing is most useful when a baby or child has signs such as a high-pitched cry, low muscle tone, developmental delay, or congenital differences, or when pregnancy ultrasound findings raise concern. It is not usually a routine screening test for healthy adults, but confirming the chromosome change can guide medical follow-up, therapies, and family counseling.
Diagnosis
Monosomy 5p is usually diagnosed when a baby or child has a pattern of signs that fit together, such as a very high-pitched cry, slow development, low muscle tone, or feeding difficulties. In many living with Monosomy 5p, the diagnosis is confirmed with chromosome testing rather than symptoms alone. Getting a diagnosis is often a turning point toward answers and support.
Doctors look at growth, muscle tone, feeding, development, and physical features that can suggest Monosomy 5p. A high-pitched cry in infancy can be one of the early clues, although not every child has the same pattern.
The main diagnosis of Monosomy 5p is made by testing the chromosomes in a blood sample. This shows whether a piece of the short arm of chromosome 5 is missing.
A chromosomal microarray can define the missing segment more precisely than older chromosome tests in many cases. This can help confirm the genetic diagnosis of Monosomy 5p and may give more detail about the size of the deletion.
Sometimes doctors use a targeted lab test called FISH to check specifically for the missing part of chromosome 5. This may be used to confirm a suspected diagnosis or clarify earlier results.
How is Monosomy 5p diagnosed?
Doctors often suspect monosomy 5p when a baby or child has a pattern of signs, such as a very high-pitched cry, slower development, being unusually floppy, or a smaller-than-expected head size. The diagnosis is confirmed with a blood test that checks the chromosomes, showing that a piece of chromosome 5 is missing. It can also be found before birth through prenatal testing if an ultrasound or screening test raises concern.
Stages of Monosomy 5p
Monosomy 5p does not have defined progression stages. That is because it is a genetic condition present from birth, rather than an illness that typically moves through set phases over time. Doctors usually start with a conversation about development, feeding, muscle tone, and any concerns with crying, speech, learning, or growth, since early symptoms of Monosomy 5p can vary from one child to another. The diagnosis is usually confirmed with chromosome testing, and follow-up care focuses on monitoring development, hearing, heart health, and support needs over time.
Outlook and prognosis
Outlook in monosomy 5p varies widely with the size of the deletion and the severity of associated problems, but many affected people survive into adulthood, especially when major heart defects or other serious congenital complications are absent. Early infancy carries the highest medical risk because feeding difficulties, poor growth, breathing problems, and infections can be significant, and severe malformations can increase mortality. Developmental delay and intellectual disability are usually lifelong, yet early intervention, speech and physical therapy, and appropriate educational and behavioral support can improve function and quality of life. Some children need ongoing care for scoliosis, hearing or vision problems, sleep issues, and constipation, but these problems are often manageable. Overall life expectancy can be near normal in milder cases, while prognosis is less favorable in those with complex organ involvement or profound medical fragility.
Long-term effects
For many living with Monosomy 5p, the long-term picture is shaped less by a single medical problem and more by how development, communication, movement, and general health unfold over time. Long-term effects vary widely, with some people needing extensive lifelong support and others gaining more independence than expected. In childhood and adulthood alike, the long-term effects of Monosomy 5p often center on learning, speech, behavior, and day-to-day physical needs.
Global developmental delay and intellectual disability are common long-term features of Monosomy 5p. Many people reach milestones later than expected, and learning often continues at a slower pace into adult life. The degree of support needed can vary widely from one person to another.
Speech and language are often among the most affected areas. Some people with Monosomy 5p use only a few words or short phrases, while others rely partly or mainly on gestures, pictures, or communication devices. Understanding language may be stronger than spoken expression in some cases.
Low muscle tone early in life can lead to lasting effects on posture, coordination, and balance. Some may walk later, tire more easily, or have a less steady gait as they grow older. Fine motor tasks such as dressing, writing, or using utensils can also remain difficult.
Many living with Monosomy 5p have attention, hyperactivity, impulsive behavior, or frustration linked to communication and sensory needs. Some show repetitive behaviors, strong emotional reactions, or features also seen with autism. These patterns may change with age but can continue into adulthood.
How is it to live with Monosomy 5p?
Living with monosomy 5p can look very different from one person to another, but for many it means a mix of developmental delays, speech and learning challenges, and sometimes medical needs that make daily routines slower and more structured. Many people with monosomy 5p benefit from ongoing support with communication, school, mobility, or self-care, yet with early therapies, steady routines, and the right accommodations, they can make meaningful progress and take part in family, school, and community life. For parents, siblings, and other caregivers, life often involves extra appointments, advocacy, and hands-on help, but it can also bring strong family bonds and a deep appreciation for each step forward.
Treatment and drugs
There is no single cure for Monosomy 5p, so treatment focuses on the challenges each child or adult is living with, such as feeding problems, delayed speech, low muscle tone, learning difficulties, or heart and airway issues. In everyday life, this often means a mix of early support services like physical, occupational, and speech therapy, along with regular follow-up for growth, hearing, vision, and development. Treatment often looks different for each person, and some people with Monosomy 5p may also need medicines for related problems such as seizures, reflux, constipation, sleep trouble, or behavior concerns. If a structural problem is present, like a heart defect or severe scoliosis, doctors may recommend surgery or other specialist care. Because the early symptoms of Monosomy 5p can vary a lot, care is usually coordinated by a team that may include a pediatrician, genetic specialist, therapists, and other doctors as needed.
Can you cure Monosomy 5p?
No, there is currently no cure for Monosomy 5p, because it happens when a small piece of genetic material is missing and doctors cannot replace that missing piece. Treatment focuses on helping with day-to-day needs and related health problems, such as feeding, speech, learning, movement, and any heart or breathing issues, so many living with Monosomy 5p can make progress and feel better supported.
Non-drug treatment
Daily life with Monosomy 5p often centers on communication, feeding, movement, and learning, so treatment usually focuses on practical supports rather than medicines. Supportive therapies can help build skills step by step, especially when started early and adjusted as a child grows. For many families, early developmental support for Monosomy 5p makes the biggest difference in day-to-day progress and independence.
Early intervention brings together therapy and developmental support during infancy and early childhood. It can help with movement, feeding, communication, and learning while the brain is developing quickly.
Physical therapy can improve muscle strength, balance, posture, and coordination. Many living with Monosomy 5p benefit from help with sitting, walking, climbing stairs, and other everyday movements.
Occupational therapy focuses on daily skills such as dressing, grasping utensils, play, and hand use. It may also help with sensory challenges and finding easier ways to manage routines at home or school.
Speech and language therapy supports speaking, understanding, and social communication. If speech is limited, therapists may introduce sign language, picture systems, or communication devices so needs and feelings can still be expressed.
Your genes may have an impact on how drugs work for you
For people living with monosomy 5p, there is no well-established evidence that the condition itself changes how most medicines work in a predictable way. In day-to-day care, medicine response is usually shaped more by the symptoms being treated, a person’s age and size, other health issues, and side effects; for example, a child taking medicine for seizures or sleep may do well on one dose while another may become unusually sleepy or need careful dose changes. Because of this, doctors usually focus on close follow-up and adjusting treatment to the individual rather than using genetic drug testing as a routine part of care for this condition.
Pharmacological treatments
Daily life with Monosomy 5p can involve a mix of challenges, from seizures or reflux to trouble sleeping, attention problems, or anxiety, and medicines are used to treat these symptoms rather than the chromosome change itself. Medication can feel like a big step, but for many living with Monosomy 5p, the goal is simply to ease specific problems and make eating, sleeping, learning, or comfort a little easier. There is no single drug that treats Monosomy 5p itself, so medications for Monosomy 5p are chosen case by case.
If Monosomy 5p includes seizures, doctors may use anti-seizure drugs such as levetiracetam, valproic acid, lamotrigine, or oxcarbazepine. The choice depends on seizure type, age, other health issues, and side effects.
Some people with Monosomy 5p need medicine for acid reflux, especially if feeding is painful or there is frequent vomiting. Common options include omeprazole or lansoprazole, and sometimes famotidine is used.
Constipation can be an ongoing problem, especially when low muscle tone, limited mobility, or feeding difficulties are part of the picture. Polyethylene glycol is often used first, and lactulose may also help keep stools softer and easier to pass.
When hyperactivity, impulsive behavior, or poor focus get in the way of school or daily routines, doctors may consider medicines also used for ADHD. These can include methylphenidate, amphetamine salts, atomoxetine, guanfacine, or clonidine, and not everyone responds to the same medication in the same way.
Genetic influences
For families, one of the first questions is often whether Monosomy 5p happened by chance or could affect future pregnancies. In Monosomy 5p, the genetic change is a missing piece of the short arm of chromosome 5, often written as 5p-, and the loss of genes in that region causes the condition. Most cases happen as a new change around conception, so nothing a parent did caused it. Less often, the missing piece is linked to a chromosome rearrangement in a parent, which is why testing parents can help clarify whether Monosomy 5p is inherited in a given family. Understanding whether a condition is inherited can guide next steps. A genetics specialist can explain recurrence risk, discuss family planning, and decide whether chromosome testing for relatives would be useful.
Is Monosomy 5p genetic?
Genetics are central to Monosomy 5p, because it is caused by missing genetic material on the short arm of chromosome 5. Genetic variations, especially the size and exact location of the missing segment, can influence how Monosomy 5p affects someone.
Having a genetic risk is not necessarily a diagnosis
Genetic variants are a usual part of human biology and are widely seen in the general population. Most do not have a direct effect on health and simply reflect normal human diversity. For many genes, carrying a variant tied to a condition suggests a possible association rather than a definite diagnosis, especially when more than one gene and environmental factors are involved. In some situations, however, a single well-characterized variant in a particular gene can be enough to confirm a diagnosis.
Pharmacogenetics—how genetics influence drug effects
For families living with Monosomy 5p, treatment is usually shaped by the day-to-day issues a child has, such as feeding trouble, low muscle tone, reflux, or seizures. No medicine can replace the missing piece of chromosome 5, so care focuses on therapies, school support, and medicines only when a specific symptom needs treatment. The exact genes missing can affect which health problems are more likely, which helps doctors plan monitoring and support, but it does not usually point to one standard drug for everyone with Monosomy 5p.
Genetics is only one factor, and when medicines are used, doctors usually choose them based more on the symptom being treated, the child’s age and weight, swallowing ability, and other medical issues. In most cases, pharmacogenetic testing is not a routine part of Monosomy 5p care, unless there is a separate reason to check how someone may respond to a particular drug. This is why families searching for how genetics affect medication response in Monosomy 5p often hear that treatment is highly individualized and may change over time.
Interactions with other conditions
People living with monosomy 5p often need care that looks at the whole body, because this condition can occur alongside heart defects, feeding problems, breathing issues, hearing loss, vision problems, and seizures. In everyday life, that may mean a child who is already working hard to eat and grow has a tougher time during a chest infection, or sleep becomes more disrupted if reflux or airway problems are also present. Doctors call it a comorbidity when two conditions occur together. Many with monosomy 5p also have low muscle tone and developmental delays, which can make constipation, repeated ear infections, or trouble clearing mucus more likely and may affect learning, speech, and mobility over time. Because the signs vary, interactions with other illnesses can look different from person to person, and early symptoms of monosomy 5p may overlap with problems first noticed in the heart, lungs, or feeding. Care usually works best when the pediatrician, therapists, and specialists share information, so related conditions are found early and treated in a coordinated way.
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 Monosomy 5p?
Other genetic conditions can sometimes look similar to monosomy 5p, especially Wolf-Hirschhorn syndrome and some other chromosome changes that can also cause slow development, low muscle tone, feeding problems, and differences in facial features. In babies, problems that affect the brain or voice box can also lead to a weak or unusual cry, so doctors usually use genetic testing to tell these conditions apart.
History
For many families, the first clues to monosomy 5p were not found in a lab but in everyday life. A baby might have a very high-pitched cry, feed slowly, or take longer to gain head control, and doctors gradually began to notice that these features often appeared together. In 1963, researchers gave this pattern a clearer medical description, which helped separate monosomy 5p from other conditions that can affect early development.
At first, understanding came mostly from careful observation of babies and children as they grew. Doctors recognized that many living with monosomy 5p could share certain features, such as developmental delay, low muscle tone, and differences in growth, while also varying a lot from one child to another. Once considered rare, now recognized as better than before, monosomy 5p is understood as a condition with a broad range of needs and abilities rather than one fixed picture.
As testing methods improved over the following decades, doctors were able to look more closely at chromosomes and confirm what earlier clinical descriptions had suggested. That made diagnosis more accurate and also helped explain why some children have milder or more noticeable features than others. In recent decades, awareness has grown, and this has made it easier for families to get answers earlier, especially when early symptoms of monosomy 5p show up in infancy.
The history of monosomy 5p also reflects a wider change in medicine. Earlier descriptions focused heavily on visible features, but care has shifted toward supporting communication, feeding, movement, learning, and family life over time. Knowing this history can be reassuring: although the condition was first recognized through a small set of signs, today there is a much fuller understanding of how people with monosomy 5p can grow, learn, and benefit from tailored support.