• Subcortical Band Heterotopia

Disease at a Glance

Summary
Subcortical band heterotopia, also known as double cortex syndrome, is a condition of abnormal brain development that is present from birth. This condition which primarily affects females, occurs when neurons migrate to an area of the brain where they are not supposed to be (heterotopia), and form abnormal areas that appear as band-like clusters of white tissue underneath the gray tissue of the cerebral cortex (subcortical), creating the appearance of a double cortex. Symptoms associated with Subcortical band heterotopia vary from severe intellectual disability and epilepsy to normal intelligence with mild or no epilepsy. Subcortical band heterotopia is most often caused by genetic changes in the DCX gene. The condition is inherited in an X-linked dominant pattern. Some cases may be caused by a small deletion on chromosome 17 involving the LIS1 gene.
Resource(s) for Medical Professionals and Scientists on This Disease:
  • RareSource offers rare disease gene variant annotations and links to rare disease gene literature.

About Subcortical band heterotopia

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

  • Population Estimate:This section is currently in development.
  • Symptoms:This section is currently in development.
  • Cause:This condition is caused by a change in the genetic material (DNA).
  • Organizations:Patient organizations are available to help find a specialist, or advocacy and support for this specific disease.
  • Categories:Neurological DiseaseBirth DefectGenetic Disease
When Do Symptoms of Subcortical band heterotopia Begin?
This section is currently in development. 

Symptoms

This information is currently in development. 

Causes

Genetic Disease

Subcortical band heterotopia is a genetic disease, which means that it is caused by one or more genes not working correctly.

Disease-causing variants, or differences, in the following gene(s) are known to cause this disease: DCX, EML1

What Is a Gene?

Understanding what genes are and how changes in genes may affect the body can help you on the journey to diagnosis and treatment of a genetic disease.

Genes are part of our DNA, the basic genetic material found in each of our body's cells. Cells are the building blocks of all living things and specialized cells form our body's organs and tissues. DNA is found in the nucleus of a cell and, in humans, is packaged into 23 pairs of chromosomes with the help of special proteins.

Each gene performs a different job in our cells. Some genes serve as the instructions to make proteins. Proteins are needed for the structure, function, and regulation of the body's cells, tissues, and organs. Some genes can turn other genes on or off. Others make RNA molecules that are involved in chemical reactions in the body.

Sources to Learn More: What Is a Gene? (MedlinePlus); What Are Proteins and What Do They Do? (MedlinePlus)Understanding what genes are and how changes in genes may affect the body can help you on the journey to diagnosis and treatment of a genetic disease.

Genes are part of our DNA, the basic genetic material found in each of our body's cells. Cells are the building blocks of all living things and specialized cells form our body's organs and tissues. DNA is found in the nucleus of a cell and, in humans, is packaged into 23 pairs of chromosomes with the help of special proteins.

Each gene performs a different job in our cells. Some genes serve as the instructions to make proteins. Proteins are needed for the structure, function, and regulation of the body's cells, tissues, and organs. Some genes can turn other genes on or off. Others make RNA molecules that are involved in chemical reactions in the body.

Sources to Learn More: What Is a Gene? (MedlinePlus); What Are Proteins and What Do They Do? (MedlinePlus)
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Inheritance

All individuals inherit two copies of most genes. The number of copies of a gene that need to have a disease-causing variant affects the way a disease is inherited. This disease is inherited in the following pattern(s):

X-Linked Recessive Inheritance

X-linked means the gene is located on the X chromosome, one of two sex chromosomes. Genes, like chromosomes, usually come in pairs. Recessive means that when there are two copies of the responsible gene, both copies must have a disease-causing change (pathogenic variant) in order for a person to have the disease. Mutation is an older term that is still sometimes used to mean pathogenic variant.

Because women have two X chromosomes, a pathogenic variant for an X-lined recessive disease generally needs to occur in both copies of the gene to cause the disease. Because men have one X chromosome and thus only one copy of the gene, a pathogenic variant in their one copy is enough to cause the disease. Women who have a pathogenic variant in one copy of the gene, are called carriers. In rare cases, women carriers may experience mild to moderate symptoms but most have no symptoms.

A woman who carries one X-linked gene variant has a 50% (1 in 2) chance of having a son with the disease and a 50% (1 in 2) chance of having a daughter who is a carrier. A man with an X-linked recessive disease cannot pass on the disease to his sons, but all of his daughters will be carriers. If a male child is the first person in a family with the disease, the pathogenic variant may have been inherited from the mother or may have occurred by chance for the first time in the child (de novo).X-linked means the gene is located on the X chromosome, one of two sex chromosomes. Genes, like chromosomes, usually come in pairs. Recessive means that when there are two copies of the responsible gene, both copies must have a disease-causing change (pathogenic variant) in order for a person to have the disease. Mutation is an older term that is still sometimes used to mean pathogenic variant.

Because women have two X chromosomes, a pathogenic variant for an X-lined recessive disease generally needs to occur in both copies of the gene to cause the disease. Because men have one X chromosome and thus only one copy of the gene, a pathogenic variant in their one copy is enough to cause the disease. Women who have a pathogenic variant in one copy of the gene, are called carriers. In rare cases, women carriers may experience mild to moderate symptoms but most have no symptoms.

A woman who carries one X-linked gene variant has a 50% (1 in 2) chance of having a son with the disease and a 50% (1 in 2) chance of having a daughter who is a carrier. A man with an X-linked recessive disease cannot pass on the disease to his sons, but all of his daughters will be carriers. If a male child is the first person in a family with the disease, the pathogenic variant may have been inherited from the mother or may have occurred by chance for the first time in the child (de novo).
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Advocacy and Support Groups

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. Please contact an organization directly if you have questions about the information or resources it provides.

Patient Organizations

5 Organizations

Organization Name

Who They Serve

Helpful Links

Country

Epilepsy Foundation
People With

Subcortical Band Heterotopia

Helpful Links
Country

United States

EveryLife Foundation for Rare Diseases
People With

Rare Diseases

Helpful Links
Country

United States

Genetic Alliance
People With

Rare Diseases

Helpful Links
Country

United States

Global Genes
People With

Rare Diseases

Helpful Links
Country

United States

National Organization for Rare Disorders
People With

Rare Diseases

Helpful Links
Country

United States

Participating in Clinical Studies

Clinical studies are part of clinical research and at the heart of all medical advances, including rare diseases. Participating in research helps researchers 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 the different types of clinical studies, consent forms, questions you should ask before participating in clinical studies, and the difference between research and medical treatment.

Why Participate in Clinical Studies?

People participate in clinical trials for a variety of reasons. Participants with a disease may participate to help others, but also to possibly receive the newest treatment and additional care from clinical study staff. Healthy volunteers may also participate to help others and to contribute to moving science forward.

How Do You Find the Right Clinical Study?

To find the right clinical study we recommend you:

  • Use ClincalTrials.gov button below to search for studies by disease, terms, or country.
  • Consult doctors, other trusted medical professionals, and patient organizations.
  • Enroll in databases to allow researchers from participating institutions to find you.

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.

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 the different types of clinical studies, consent forms, questions you should ask before participating in clinical studies, and the difference between research and medical treatment.

Why Participate in Clinical Studies?

People participate in clinical trials for a variety of reasons. Participants with a disease may participate to help others, but also to possibly receive the newest treatment and additional care from clinical study staff. Healthy volunteers may also participate to help others and to contribute to moving science forward.

How Do You Find the Right Clinical Study?

To find the right clinical study we recommend you:

  • Use ClincalTrials.gov button below to search for studies by disease, terms, or country.
  • Consult doctors, other trusted medical professionals, and patient organizations.
  • Enroll in databases to allow researchers from participating institutions to find you.

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.

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.
Please contact GARD if you need help finding additional information or resources on rare diseases, including clinical studies. Our Information Specialists are available to you by phone or by filling out our contact form. Note, GARD cannot enroll individuals in clinical studies.
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.
Please contact GARD if you need help finding additional information or resources on rare diseases, including clinical studies. Our Information Specialists are available to you by phone or by filling out our contact form. Note, GARD cannot enroll individuals in clinical studies.

Learn about symptoms, cause, support, and research for a rare disease. 

Take steps toward getting a diagnosis by working with your doctor, finding the right specialists, and coordinating medical care.

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Take steps toward getting a diagnosis by working with your doctor, finding the right specialists, and coordinating medical care.

Last Updated: February 2023