ALTERNATE NAMES

FOXG1-Related Disorder; FOXG1-Related Encephalopathy; FOXG1-Related Epileptic-Dyskinetic Encephalopathy

DESCRIPTION

FOXG1 syndrome is a genetic condition that severely impairs growth of the brain and body in infants. Brain malformation associated with FOXG1 syndrome follows a distinct pattern in which the corpus callosum (the tissue that connects the right and left hemispheres) is unusually thin, along with reduced formation of brain folds and white matter.

Children affected by FOXG1 syndrome exhibit small stature and microcephaly. The effects on the brain cause a wide array of neurological and intellectual problems, including epilepsy, sleep disturbances, feeding trouble, and behavioral issues.

The condition is caused by the mutation or complete absence of the FOXG1 gene, which is critical to brain development.

FOXG1 syndrome was previously thought to be a variant of Rett syndrome; however, FOXG1 syndrome affects males and females, while Rett syndrome is observed only in females.

DIAGNOSTIC TESTING, PHYSICAL FINDINGS, AND ICD-9-CM/ICD-10-CM CODING

Diagnostic testing: A suspected diagnosis of FOXG1 syndrome can be confirmed through genetic sequencing tests on the patient’s blood.

Physical findings: Physical signs and symptoms of FOXG1 syndrome include:

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  Small stature and head size;

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  Seizures;

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  Cortical vision impairment;

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  Global developmental delays;

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  Sleep disorders; and

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  Involuntary movements of the extremities.

ICD-9: 330.8

ICD-10: F84.8

PROGRESSION

The developmental disabilities of FOXG1 syndrome are debilitating from early infancy and usually do not improve. Most children with FOXG1 syndrome never learn to walk or speak and require lifelong help performing basic tasks such as eating and using the toilet.

As FOXG1 syndrome is a recently identified and very rare disease, conclusive data about its effect on life expectancy is not yet available.

TREATMENT

There is no cure for FOXG1 syndrome. Treatment is supportive; lifelong care and assistance with activities of daily living are required.

Suggested MER for Evaluation:

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  Clinical history and examination that describes the diagnostic features of the impairment; and

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  Genetic sequencing tests confirming mutation of the FOXG1 gene.

Suggested Listings for Evaluation:

DETERMINATION

LISTING

REMARKS

Meets

11.02

11.17

12.05

110.08

111.02

111.17

112.02

112.05

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