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Disease Information

Summary

Sotos syndrome is a disorder characterized by a distinctive facial appearance, overgrowth in childhood, and learning disabilities or delayed development of mental and movement abilities. Characteristic facial features include a long, narrow face; a high forehead; flushed (reddened) cheeks; and a small, pointed chin.  In addition, the outside corners of the eyes may point downward (down-slanting palpebral fissures). This facial appearance is most notable in early childhood. Affected infants and children tend to grow quickly; they are significantly taller than their siblings and peers and have an unusually large head. However, adult height is usually in the normal range. People with Sotos syndrome often have intellectual disability, and most also have neurodevelopmental disorders. Conditions that commonly occur in people with Sotos syndrome include autism spectrum disorder, attention-deficit/hyperactivity disorder (ADHD), phobias, obsessions and compulsions, tantrums, and impulsive behaviors. Problems with speech and language are also common.  Affected individuals often have a stutter, a monotone voice, and problems with sound production. Additionally, weak muscle tone (hypotonia) may delay other aspects of early development, particularly motor skills such as sitting and crawling. Other signs and symptoms of Sotos syndrome can include an abnormal side-to-side curvature of the spine (scoliosis), seizures, heart or kidney defects, hearing loss, and problems with vision. Some infants with this disorder experience yellowing of the skin and whites of the eyes (jaundice) and poor feeding. A small percentage of people with Sotos syndrome have developed cancer, most often in childhood, but no single form of cancer occurs most frequently with this condition. It remains uncertain whether Sotos syndrome increases the risk of specific types of cancer. If people with this disorder have an increased cancer risk, it is only slightly greater than that of the general population.

About Sotos syndrome

Many rare diseases have limited information. Currently, GARD aims to provide the following information for this disease:

  • Symptoms:May start to appear during Pregnancy and as a Newborn.
  • Cause:This disease is caused by changes to the number or structure of a person’s chromosomes.
  • Organizations:Patient organizations dedicated to this rare disease are available on GARD, or you may contact a GARD Information Specialist for additional information.
  • Categories:Genetic diseases(Genetic diseases affect the DNA, or genetic instructions, which directs how tissues, organs, and body systems function.)Neurological diseases(Neurological diseases affect the brain, spinal cord, cranial nerves, autonomic nerves, or other peripheral nerves.)Endocrine diseases(Endocrine diseases affect hormone production or how the body responds to a specific hormone(s).)Birth defects(Birth defects are structural changes present at birth that can affect almost any part of the body, including how the body looks, works, or both.)

Resource(s) for Medical Professionals and Scientists on This Disease:

  • ClinGen provides expert-reviewed information on genes and gene variants for use in research and medicine.
  • GeneReview provides clinical information on genetic diseases, including diagnosis, treatment, and genetic counseling.
  • MONDO provides GARD with information for this disease.
  • Orphanet provides GARD with information for this disease.
  • RARe-SOURCE™ offers rare disease gene variant annotations and links to rare disease gene literature.

Resource(s) for Medical Professionals and Scientists on This Disease:

  • ClinGen provides expert-reviewed information on genes and gene variants for use in research and medicine.
  • GeneReview provides clinical information on genetic diseases, including diagnosis, treatment, and genetic counseling.
  • MONDO provides GARD with information for this disease.
  • Orphanet provides GARD with information for this disease.
  • RARe-SOURCE™ offers rare disease gene variant annotations and links to rare disease gene literature.

About Sotos syndrome

Many rare diseases have limited information. Currently, GARD aims to provide the following information for this disease:

  • Symptoms:May start to appear during Pregnancy and as a Newborn.
  • Cause:This disease is caused by changes to the number or structure of a person’s chromosomes.
  • Organizations:Patient organizations dedicated to this rare disease are available on GARD, or you may contact a GARD Information Specialist for additional information.
  • Categories:Genetic diseases(Genetic diseases affect the DNA, or genetic instructions, which directs how tissues, organs, and body systems function.)Neurological diseases(Neurological diseases affect the brain, spinal cord, cranial nerves, autonomic nerves, or other peripheral nerves.)Endocrine diseases(Endocrine diseases affect hormone production or how the body responds to a specific hormone(s).)Birth defects(Birth defects are structural changes present at birth that can affect almost any part of the body, including how the body looks, works, or both.)

Causes

What Causes This Disease?

Genetic Mutations

Changes in your genes (also called variants) cause Sotos syndrome.

Genes are sections of DNA that contains instructions that help the body grow, develop, and function. A genetic variant is a change in your DNA's order. Parents may pass variants to their children, or they may occur randomly. They may result from viruses, environmental factors, such as UV radiation, or a combination of causes.

Most genetic variants do not cause disease. However, some can affect how a gene works and interfere with the body's normal functions. A pathogenic variant is one that causes disease.

If you think you may have this disease, collect your family health history (CDC). It may help you and your medical team to know about family members who have had the disease or similar symptoms and when those symptoms first appeared.

Read more about genetic disorders (NIH MedlinePlus). 

Genetic Mutations

Changes in your genes (also called variants) cause Sotos syndrome.

Genes are sections of DNA that contains instructions that help the body grow, develop, and function. A genetic variant is a change in your DNA's order. Parents may pass variants to their children, or they may occur randomly. They may result from viruses, environmental factors, such as UV radiation, or a combination of causes.

Most genetic variants do not cause disease. However, some can affect how a gene works and interfere with the body's normal functions. A pathogenic variant is one that causes disease.

If you think you may have this disease, collect your family health history (CDC). It may help you and your medical team to know about family members who have had the disease or similar symptoms and when those symptoms first appeared.

Read more about genetic disorders (NIH MedlinePlus). 

Known Genetic Mutations

Sotos syndrome is caused by genetic mutations in the following known gene(s):

NSD1
Learn more about these genes by searching them on the National Library of Medicine (NLM).

Given these known genetic mutation(s), you may want to ask your health care team if genetic testing is right for you. Genetic tests are laboratory tests that use samples of blood, saliva, or other tissues to help identify changes in genes, chromosomes, or proteins. Genetic testing can help confirm or rule out a suspected genetic disease or can provide other useful information to your health care team. Learn more about genetic testing from the National Human Genome Research Institute (NHGRI).

Chromosomal Changes

Sotos syndrome is caused by a change in the number of chromosomes a person has, or a change in their structure.  Chromosomes are structures within cells that hold all our genes. People usually have 46 chromosomes; 23 come from the biological mother and 23 come from the biological father. Most of the time, chromosomal changes occur randomly in the sperm or egg, but some changes are known to be passed on from parent to child. Learn more about chromosomal diseases from the National Human Genome Research Institute (NHGRI).

Given the known chromosomal changes for this disease, you may want to ask your health care team if chromosome testing is right for you. Results from chromosome testing can confirm or rule out a suspected chromosomal disease or help determine a person’s chance of passing on a disease. Visit the NHGRI website to learn about microarray technology used in chromosomal testing, understand how a karyotype can be used to determine chromosomal abnormalities, and discover the FISH lab technique used to detect a specific DNA sequence on a chromosome.

Can diseases be passed down from parent to child?

A biological parent can sometimes pass down genetic changes, called mutations, that cause a disease or increase the chances of developing it. This is called inheritance. Knowing if other family members have had the disease, also known as your family health history, can give your medical team important information. The Surgeon General offers a tool to help you collect your family health history.

Autosomal Dominant

Autosomal means the gene involved is located on one of the numbered chromosomes. Dominant means that a child only needs to inherit one copy of the mutated gene, from either biological parent, to be affected by the disease.

People affected by an autosomal dominant disease have a 50% chance of passing on the mutated gene to their biological child.

Learn more about inheritance patterns from the National Library of Medicine (NLM).

Autosomal Dominant

Autosomal means the gene involved is located on one of the numbered chromosomes. Dominant means that a child only needs to inherit one copy of the mutated gene, from either biological parent, to be affected by the disease.

People affected by an autosomal dominant disease have a 50% chance of passing on the mutated gene to their biological child.

Learn more about inheritance patterns from the National Library of Medicine (NLM).

Autosomal Recessive

Autosomal means the gene involved is located on one of the numbered chromosomes. Recessive means that a child must inherit two copies of the mutated gene, one from each biological parent, to be affected by the disease. A carrier is a person who only has one copy of the genetic mutation. A carrier usually doesn't show any symptoms of the disease.

If both biological parents are carriers, there is a 25% their child inherits both copies of the mutated gene and is affected by the disease. Additionally, there is a 50% chance their child inherits only one copy of the mutated gene and is a carrier.

Learn more about inheritance patterns from the National Library of Medicine (NLM).

When Do Symptoms of Sotos syndrome Begin?

Symptoms of this disease may start to appear during Pregnancy and as a Newborn.

The age symptoms may begin to appear differs between diseases. Symptoms may begin in a single age range, or during several age ranges. The symptoms of some diseases may begin at any age. Knowing when symptoms may have appeared can help medical providers find the correct diagnosis.
  1. Prenatal Selected
    Before Birth
  2. Newborn Selected
    Birth-4 weeks
  3. Infant
    1-23 months
  4. Child
    2-11 years
  5. Adolescent
    12-18 years
  6. Adult
    19-65 years
  7. Older Adult
    65+ years
Symptoms may start to appear during Pregnancy and as a Newborn.
This information comes from Orphanet

Symptoms

You may have one or more symptoms, and they may be mild or severe. Having some or all of these symptoms does not mean you have this disease. Only a health care provider can diagnose you.

Common

Many people have these, but not everyone.

  • Advanced bone age (Accelerated skeletal maturation)
  • Astigmatism
  • Behavioral abnormality (Atypical behavior)
  • Brain imaging abnormality
  • Chronic infections of the middle ear (Chronic otitis media)
  • Coarse facial features
  • Constipation
  • Double-Jointed (Joint hypermobility)
  • Downward slanting of the opening between the eyelids (Downslanted palpebral fissures)
  • Feeding difficulties
  • Flushing
  • Global developmental delay
  • Hearing impairment
  • Increased arm span
  • Increased head circumference
  • Intellectual disability, mild (Mild intellectual disability)
  • Long face
  • Long, narrow head (Dolichocephaly)
  • Low muscle tone (Hypotonia)
  • Narrow face
  • Prolonged yellowing of skin in newborn (Prolonged neonatal jaundice)
  • Prominent forehead
  • Scoliosis
  • Seizure
  • Sparse scalp hair at front of head (Sparse anterior scalp hair)
  • Tall chin
  • Tall stature

Uncommon

Some people have these, but most people do not.

  • Abnormal dentition (Abnormality of the dentition)
  • Abnormal vertebral morphology
  • Abnormality of the heart (Abnormal heart morphology)
  • Abnormality of the kidney
  • Absence of adult teeth (Agenesis of permanent teeth)
  • Absent kidney (Renal agenesis)
  • Acid reflux (Gastroesophageal reflux)
  • Acute lymphoblastic leukemia
  • Aggressive behavior
  • An opening in the wall separating the top two chambers of the heart (Atrial septal defect)
  • Ankle flexion contracture
  • Anxiety
  • Aplasia/Hypoplasia of the corpus callosum
  • Astrocytoma
  • Attention deficit (Attention deficit hyperactivity disorder)
  • Autistic behavior
  • Bilateral camptodactyly
  • Brief seizures with staring spells (Generalized non-motor (absence) seizure)
  • Bulge in wall of large artery that carries blood away from heart (Aortic aneurysm)
  • Cancer of early nerve cells (Neuroblastoma)
  • Cavum septum pellucidum
  • Cerebellar vermis hypoplasia
  • Cholesteatoma
  • Close sighted (Myopia)
  • Clouding of the lens of the eye (Cataract)
  • Club feet (Talipes equinovarus)
  • Conductive deafness (Conductive hearing impairment)
  • Congenital posterior urethral valve
  • Craniosynostosis
  • Cross-eyed (Strabismus)
  • Decreased fertility
  • Degeneration of cerebrum (Cerebral atrophy)
  • Delayed eruption of permanent teeth
  • Double ureter (Ureteral duplication)
  • Dyscalculia
  • Early and severe mental retardation (Severe intellectual disability)
  • Enlarged cisterna magna
  • Enlarged colon lacking nerve cells (Aganglionic megacolon)
  • Failure of development of between one and six teeth (Hypodontia)
  • Farsightedness (Hypermetropia)
  • Flat feet (Pes planus)
  • Flexed joint that cannot be straightened (Flexion contracture)
  • Fluid accumulation in lower limbs (Pedal edema)
  • Focal impaired awareness seizure
  • Funnel chest (Pectus excavatum)
  • Generalized myoclonic seizure
  • Grand mal seizures (Bilateral tonic-clonic seizure)
  • Hip contracture
  • Hole in heart wall separating two lower heart chambers (Ventricular septal defect)
  • Hunched back (Kyphosis)
  • Hydrocele testis
  • Hydronephrosis
  • Hypospadias
  • Incoordination
  • Increased size of skull (Macrocephaly)
  • Inguinal hernia
  • Involuntary, rapid, rhythmic eye movements (Nystagmus)
  • IQ between 34 and 49 (Moderate intellectual disability)
  • Large hands
  • Neoplasm
  • Patchy darkened skin (Hyperpigmentation of the skin)
  • Patchy lightened skin (Hypopigmentation of the skin)
  • Patent ductus arteriosus
  • Phimosis
  • Pulmonary bleb
  • Renal failure (Renal insufficiency)
  • Sacrococcygeal teratoma
  • Small cell lung carcinoma
  • Small nail
  • Strawberry mark (Hemangioma)
  • Tremor
  • Umbilical hernia
  • Underactive thyroid (Hypothyroidism)
  • Undescended testes (Cryptorchidism)
  • Ureteropelvic junction obstruction
  • Ventriculomegaly
  • Vesicoureteral reflux
  • Webbed 2nd and 3rd toes (2-3 toe syndactyly)
This information comes from the Human Phenotype Ontology (HPO)

Navigating Health Care Decisions

On average, it can take more than six years to receive an accurate diagnosis. Many primary care providers (PCPs) may not be familiar with rare diseases, and patients often need to visit multiple specialists or seek second opinions to get answers.

If a diagnosis remains unclear, visiting a multidisciplinary care center or university hospital may help. These centers bring together teams of specialists who can work together to evaluate symptoms and coordinate a diagnosis. This team-based approach is also helpful after a diagnosis, when managing care for rare diseases.

Because only about 5% of rare diseases have FDA-approved treatments, finding the right healthcare team to manage your symptoms and overall health is essential. People living with rare diseases often face challenges such as delayed diagnosis, limited treatment options, and difficulty accessing knowledgeable providers. Building a care team that understands your needs can make a significant difference in your quality of life.

Your Health Care Team

Why is building the right health care team important?

Building the right health care team is key to the diagnosis, treatment, and management of your long-term health journey living with a rare disease. Start by choosing a primary care provider (PCP). Your PCP will be your main point of contact and help coordinate care with other medical professionals. Your PCP may order tests or refer you to specialists. To find a PCP near you, use the Medicare provider search tool and enter your location and “Primary Care Provider.”

Seeing multiple specialists is important for people with rare diseases because these conditions often affect many parts of the body and require care from doctors with different expertise. Most primary care providers may not be familiar with rare diseases, so involving specialists can lead to a more accurate diagnosis and better care. A coordinated team approach ensures that all symptoms are addressed and that care is well-managed. It can also connect patients with the latest research or treatment options.

A PCP that specializes in the care of children is called a pediatrician. Use this tool by the American Academy of Pediatrics to find a pediatrician in your area by inputting your location.

These specialists may help in the diagnosis, management, and treatment of Sotos syndrome:

Anterior segment specialists are eye doctors with advanced training in diseases that affect the front part of the eye, such as the cornea, iris, and lens. They manage a variety of eye diseases, from common issues like cataracts to complex, rare, or genetic diseases that involve the anterior segment. Anterior segment specialists may perform surgeries or other treatments to improve vision and eye health.

You may want to consider bringing a copy of your medical history and a list of any medications to your appointment.

Use this directory by the American Academy of Ophthalmology to search for an anterior segment specialist in your area. Use the dropdown menu to select "Cataract/Anterior Segment". 
Orthopedists, also known as orthopedic surgeons, are doctors with specialized training in diagnosing and treating conditions that affect the bones, joints, muscles, tendons, and ligaments. They care for people with arthritis, scoliosis, sports injuries, bone fractures, and rare or inherited bone conditions. Orthopedists may use imaging tests and physical exams to identify the cause of pain, stiffness, or limited movement. Treatment may include physical therapy, medication, or surgery.

You may want to consider bringing a copy of your medical history and a list of any medications to your appointment.

Ask your primary care provider for a referral or use this directory by Medicare to search for an orthopedist specialist in your area. Search using the keyword “Orthopedics.”
Neurologists are doctors with specialized training in diagnosing and treating conditions that affect the brain, spinal cord, and nerves. These parts of the nervous system help control how the body moves, feels, and thinks. Neurologists often care for people with seizures, memory problems, muscle weakness, movement disorders, and inherited conditions such as muscular dystrophies. To better understand a person's symptoms, neurologists may use imaging tests that show the brain or spine, or tests that measure the brain’s electrical activity.

You may want to consider bringing a copy of your medical history and a list of any medications to your appointment.

Ask your primary care provider for a referral or use this directory provided by the American Board of Psychiatry and Neurology to find a specialist. 
Oncologists are doctors with specialized training in diagnosing, treating, and managing different types of cancer and conditions that could become cancerous. They may specialize in specific cancer types, such as blood cancers, breast cancer, or gastrointestinal cancers. Some oncologists also have training in rare or inherited cancers. They use a range of treatments, including surgery, chemotherapy, radiation therapy, immunotherapy, and targeted drug therapies.

You may want to consider bringing a copy of your medical history and a list of any medications to your appointment.

Ask your primary care provider for a referral or use this directory by Medicare to search for an oncologist in your area. Search using the keywords “Medical Oncology.”
Ophthalmologists are doctors with specialized training in managing serious eye problems, including those that require surgery. They may have additional experience with rare or inherited eye diseases, birth defects, or eye conditions linked to the nervous or immune system. Some ophthalmologists focus on specific areas, such as diseases of the retina or cancers of the eye. They may use imaging, vision tests, and lab work to diagnose and guide treatment.

You may want to consider bringing a copy of your medical history and a list of any medications to your appointment.

Ask your primary care provider for a referral or use this directory provided by the American Academy of Ophthalmology to find a specialist.
Geneticists are doctors trained to diagnose and manage conditions caused by genetic changes, birth defects, or metabolic disorders. Metabolic disorders affect how the body makes or uses energy. Geneticists often work alongside genetic counselors to review family history, discuss genetic risks, explain testing options, and interpret genetic test results. They help people understand how inherited conditions may affect them and their families.

You may want to consider bringing a copy of your medical history and a list of any medications to your appointment.

Ask your primary care provider for a referral or use this directory provided by the American College of Medical Genetics and Genomics to find a specialist.
Endocrinologists are doctors trained to diagnose and manage diseases related to hormones. Hormones are chemical messengers that help coordinate many body functions, including metabolism, growth, and reproduction. Endocrinologists commonly treat conditions such as diabetes, thyroid disorders, and certain hormone-related cancers. They also care for people with concerns about growth or sexual development. Treatment options may include medications, hormone replacement therapy, or surgery, depending on the condition.

You may want to consider bringing a copy of your medical history and a list of any medications to your appointment.

Ask your primary care provider for a referral or use this directory provided by the Endocrine Society to find a specialist.

Multidisciplinary Care Centers

Is It Time to Get a Second Opinion or Specialized Evaluation?

If you've visited your PCP, met with specialists, and undergone the recommended tests, but are still searching for a diagnosis, it may be time to visit an academic medical center or, for pediatric patients, a children's hospital. Academic medical centers and children's hospitals, often called multidisciplinary care centers, typically bring together specialists from different fields to work together on complex cases like rare diseases.

Multidisciplinary care centers may offer more coordinated care and be involved in clinical research, which may help reduce the time to diagnosis and provide access to emerging diagnostic tools. Specialists at these centers may have a deeper understanding of rare diseases and serve as a resource when you'd like a second opinion, particularly when test results or treatment plans are not delivering expected results.

Find hospitals that may partner with medical schools and programs in your area. 

Children’s hospitals and large teaching hospitals may also offer dedicated specialists and programs for pediatric patients with undiagnosed or rare diseases. These programs bring pediatric experts together in one place and may provide more coordinated care for your child.

Search for children's or university hospitals in your area.

Rare Disease Experts

How can you find a rare disease expert?

If a diagnosis, care management, or treatment plan remains unclear despite extensive efforts by your PCP and specialists, it may be time to find a rare disease expert for your disease, if available. A rare disease expert is a medical provider that has knowledge or training on specific rare disease(s), but there may only be a few experts in your state, region, or country. Rare disease experts may work at large research or teaching hospitals, sometimes called centers of excellence. Centers of Excellence commit to sharing knowledge and best practices that can lead to improved care and treatment for individuals living with a rare disease. 

You can also contact a GARD Information Specialist for help finding experts, centers of excellence, or clinics that focus on your disease.
You can ask your care providers for help finding an expert or use directory tools to search for experts near you. The National Organization for Rare Disorders (NORD) maintains a list of rare disease centers with experts that work together to find treatments and cures for a broad range of rare diseases. Search NORD's Center Directory to find experts near you.

Find Your Community

How can patient organizations help?

Patient organizations can help patients and families connect. They build public awareness of the disease and are a driving force behind research to improve patients' lives. They may offer online and in-person resources to help people live well with their disease. Many collaborate with medical experts and researchers.

Services of patient organizations differ, but may include:

  • Ways to connect to others and share personal stories
  • Easy-to-read information
  • Up-to-date treatment and research information
  • Patient registries
  • Lists of specialists or specialty centers
  • Financial aid and travel resources


Please note: GARD provides organizations for informational purposes only and not as an endorsement of their services. Contact a GARD Information Specialist for more information on organizations that may be dedicated to this disease. Please contact an organization directly if you have questions about the information or resources it provides.


View GARD's criteria for including patient organizations, which can be found under the FAQs on our About GARD page. Request an update or to have your organization added to GARD. 

Patient Organizations

3 Organizations

Simons Searchlight

People With

Sotos syndrome

Helpful Links
Country

United States

Sotos Syndrome Support Association

People With

Sotos syndrome

Country

United States

Chromosome Disorder Outreach

People With

Chromosome disorders

Country

United States

OrganizationPeople WithHelpful LinksCountry
Simons SearchlightSotos syndromeResearch RegistryUnited States
Sotos Syndrome Support AssociationSotos syndromeUnited States
Chromosome Disorder OutreachChromosome disordersUnited States

Participate in Research

Clinical studies are a part of clinical research and play an important role in medical advances for rare diseases. Through clinical studies, researchers may ultimately uncover better ways to treat, prevent, diagnose, and understand human diseases.

What Are Clinical Studies?

Clinical studies are medical research involving people as participants. There are two main types of clinical studies:

  1. Clinical trials determine if a new test or treatment for a disease is effective and safe by comparing groups receiving different tests/treatments.
  2. Observational studies involve recording changes over time among a specific group of people in their natural settings.

Learn more about clinical trials from this National Institutes of Health webpage.

Why Participate in Clinical Studies?

People participate in clinical trials for many reasons. People with a disease may participate to receive the newest possible treatment and additional care from clinical study staff as well as to help others living with the same or a similar disease. Healthy volunteers may participate to help others and to contribute to moving science forward.

To find the right clinical study we recommend you consult your doctors, other trusted medical professionals, and patient organizations. Additionally, you can use ClinicalTrials.gov to search for clinical studies by disease, terms, or location.

What if There Are No Available Clinical Studies?

ResearchMatch helps connect people interested in research studies  with researchers from top medical centers across the United States. Anyone from the U.S. can register with this free program funded by NIH. Researchers from participating institutions use the database to search for and invite patients or healthy volunteers who meet their study criteria to participate.

Why may you want to consider joining the All of Us Research Program?

The All of Us Research Program is inviting 1 million people from all backgrounds across the U.S. to help build one of the most diverse health databases in history. Researchers will use the data to learn how our biology, lifestyle, and environment affect health. This may one day help them find ways to treat and prevent diseases.

ClinicalTrials.gov, an affiliate of NIH, provides current information on clinical research studies in the United States and abroad. Talk to a trusted doctor before choosing to participate in any clinical study. We recommend checking this site often and searching for studies with related terms/synonyms to improve results.
Search ClinicalTrials.gov for this disease.
GARDGenetic and Rare Diseases
Information Center
Contact a GARD Information Specialist if you need help finding more information on this rare disease or available clinical studies. Please note that GARD cannot enroll individuals in clinical studies.
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Sources & References

Last Updated: September 2026