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Disease Information

Summary

FOXG1 syndrome is a condition characterized by impaired development and structural brain abnormalities. Affected infants are small at birth, and their heads grow more slowly than normal, leading to an unusually small head size (microcephaly) by early childhood. The condition is associated with a particular pattern of brain malformations that includes a thin or underdeveloped connection between the right and left halves of the brain (a structure called the corpus callosum), reduced folds and grooves (gyri) on the surface of the brain, and a smaller than usual amount of brain tissue known as white matter. FOXG1 syndrome affects most aspects of development, and children with the condition typically have severe intellectual disability. Abnormal or involuntary movements, such as jerking movements of the arms and legs and repeated hand motions, are common, and most affected children do not learn to sit or walk without assistance. Babies and young children with FOXG1 syndrome often have feeding problems, sleep disturbances, seizures, irritability, and excessive crying. Affected individuals may have autism spectrum disorder, which is characterized by limited communication and social interaction, including poor eye contact and a near absence of speech and language skills.  FOXG1 syndrome was previously described as a congenital variant of Rett syndrome, which is a similar disorder of brain development. Both disorders are characterized by impaired development, intellectual disability, and problems with communication and language. However, Rett syndrome is diagnosed almost exclusively in females, while FOXG1 syndrome affects both males and females. Rett syndrome also involves a period of apparently normal early development that does not occur in FOXG1 syndrome. Because of these differences, physicians and researchers now usually consider FOXG1 syndrome to be distinct from Rett syndrome.

About FOXG1 disorder

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

  • Symptoms:May start to appear as a Newborn.
  • Cause:This disease is caused by a change in the genetic material (DNA).
  • 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.)

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 FOXG1 disorder

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

  • Symptoms:May start to appear as a Newborn.
  • Cause:This disease is caused by a change in the genetic material (DNA).
  • 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.)

Causes

What Causes This Disease?

Genetic Mutations

Changes in your genes (also called variants) cause FOXG1 disorder.

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 FOXG1 disorder.

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

FOXG1 disorder is caused by genetic mutations in the following known gene(s):

FOXG1
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).

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).

When Do Symptoms of FOXG1 disorder Begin?

Symptoms of this disease may start to appear 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
    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 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.

  • Abnormal corpus callosum morphology
  • Abnormal gait (Gait disturbance)
  • Abnormality of movement
  • Absent speech development (Absent speech)
  • Acid reflux (Gastroesophageal reflux)
  • Autistic behavior
  • Choreoathetosis
  • Cognitive impairment
  • Constipation
  • Cross-eyed (Strabismus)
  • Decreased body weight
  • Delayed myelination
  • Difficulty sleeping (Sleep disturbance)
  • Disorder of involuntary muscle movements (Dyskinesia)
  • Dystonia
  • Excessive salivation
  • Feeding difficulties
  • Grand mal seizures (Bilateral tonic-clonic seizure)
  • Hyperactive movements (Hyperkinetic movements)
  • Inappropriate crying
  • Infantile spasms
  • Involuntary muscle stiffness, contraction, or spasm (Spasticity)
  • Low muscle tone (Hypotonia)
  • Marked growth retardation (Severe postnatal growth retardation)
  • Motor delay
  • Myoclonus
  • Orofacial dyskinesia
  • Paroxysmal bursts of laughter
  • Poor eye contact (Reduced eye contact)
  • Progressively abnormally small cranium (Progressive microcephaly)
  • Repetitive movements (Motor stereotypy)
  • Seizure affecting one half of brain (Focal-onset seizure)
  • Severe global developmental delay
  • Short stature
  • Teeth grinding (Bruxism)
  • Visual impairment

Uncommon

Some people have these, but most people do not.

  • Agenesis of corpus callosum
  • Fewer and broader ridges in brain (Pachygyria)
  • Functional respiratory abnormality (Abnormal respiratory system physiology)
  • Inability to walk
  • Kyphoscoliosis
  • Loss of developmental milestones (Developmental regression)
  • Optic disc hypoplasia
  • Poor social interactions (Reduced social responsiveness)
  • Poor speech
  • Repeated seizures without recovery between them (Status epilepticus)
  • Scoliosis
  • Stereotypical hand wringing
  • Underdevelopment of part of brain called corpus callosum (Hypoplasia of the corpus callosum)
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 FOXG1 disorder:

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. 
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.
Epileptologists are neurologists with advanced training in diagnosing and treating epilepsy and seizure disorders. They specialize in evaluating complex or drug-resistant forms of epilepsy, including rare types that may involve multiple seizure types or be linked to genetic or metabolic disorders. Epileptologists may use tools such as electroencephalogram (EEG), brain imaging, and genetic testing to help 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 by Medicare to search for an epileptologist in your area. Search using the keyword “epilepsy."

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 following organization(s) may maintain a list of experts or expert centers for people living with FOXG1 disorder:

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

FOXG1 Research Foundation

People With

FOXG1 disorder

Helpful Links
Country

United States

Believe in a Cure

People With

FOXG1 disorder

Country

United States

Epilepsy Foundation

People With

Epilepsy

Helpful Links
Country

United States

OrganizationPeople WithHelpful LinksCountry
FOXG1 Research FoundationFOXG1 disorderList of Experts
Research Registry		United States
Believe in a CureFOXG1 disorderUnited States
Epilepsy FoundationEpilepsyList of Experts
Research Registry		United 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