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FOXG1 gene

forkhead box G1

Normal Function

The FOXG1 gene provides instructions for making a protein known as forkhead box G1. This protein is a transcription factor, which means it helps regulate the activity of other genes. Specifically, the forkhead box G1 protein acts as a transcriptional repressor, turning off (repressing) the activity of certain genes when they are not needed. Researchers believe that this protein plays an important role in brain development, particularly in a region of the embryonic brain known as the telencephalon. The telencephalon ultimately develops into several critical structures, including the the largest part of the brain (the cerebrum), which controls most voluntary activity, language, sensory perception, learning, and memory.

Health Conditions Related to Genetic Changes

FOXG1 syndrome

Changes involving the FOXG1 gene cause FOXG1 syndrome, a rare disorder characterized by impaired development and structural brain abnormalities. This condition was previously described as a congenital variant of Rett syndrome, which is a similar disorder of early development. However, doctors and researchers have identified some important differences between the two conditions, so now FOXG1 syndrome is usually considered to be distinct from Rett syndrome.

At least 11 mutations within the FOXG1 gene have been identified in people with FOXG1 syndrome. The condition can also result from a deletion of genetic material from a region of the long (q) arm of chromosome 14 that includes the FOXG1 gene and several neighboring genes. All of these genetic changes prevent the production of forkhead box G1 or impair the protein's function. A shortage of this protein disrupts normal brain development starting before birth, which appears to underlie the brain malformations and severe developmental problems characteristic of FOXG1 syndrome.

More About This Health Condition

Lennox-Gastaut syndrome

MedlinePlus Genetics provides information about Lennox-Gastaut syndrome

More About This Health Condition

Other disorders

A few people have been found to have an extra copy (duplication) of the part of chromosome 14 that contains the FOXG1 gene. These duplications are associated with recurrent seizures (epilepsy) starting in infancy, intellectual disability, and severe speech impairment. Duplications of the FOXG1 gene have also been identified in several infants diagnosed with West syndrome, a condition characterized by epilepsy that begins in infancy, severe to profound intellectual disability, and related brain abnormalities. Although the mechanism is unclear, researchers believe that the extra genetic material leads to these developmental problems by altering early brain development.

Other Names for This Gene

  • BF1
  • BF2
  • brain factor 1
  • brain factor 2
  • FHKL3
  • FKH2
  • forkhead box protein G1
  • FOXG1A
  • FOXG1B
  • FOXG1C
  • HBF-1
  • HBF-2
  • HBF-3
  • HBF-G2
  • HBF2
  • HFK1
  • HFK2
  • HFK3
  • KHL2
  • oncogene QIN
  • QIN

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

Scientific Articles on PubMed

Catalog of Genes and Diseases from OMIM

Gene and Variant Databases


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The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.