DEPDC5 and GATOR1-related epilepsies are genetic focal epilepsies caused by pathogenic variants in genes that regulate the mTOR signalling pathway. The GATOR1 complex is formed by DEPDC5, NPRL2 and NPRL3.
These disorders are especially important because a genetic focal epilepsy can coexist with a structural brain abnormality such as focal cortical dysplasia.
What GATOR1 does
GATOR1 normally suppresses mTORC1 signalling when cellular nutrient conditions require restraint of growth pathways.
Loss-of-function variants in DEPDC5, NPRL2 or NPRL3 reduce this inhibitory control and can promote abnormal cortical development and neuronal excitability.
Familial focal epilepsy with variable foci
GATOR1 genes are a major cause of familial focal epilepsy with variable foci.
Different relatives may have frontal, temporal or other focal epilepsies despite sharing the same inherited variant.
Sleep-related hypermotor epilepsy
DEPDC5, NPRL2 and NPRL3 can also cause sleep-related hypermotor epilepsy.
Seizures may be brief, frequent and predominantly nocturnal.
Other focal phenotypes
GATOR1 variants have been associated with familial mesial temporal lobe epilepsy, epilepsy with auditory features, infantile spasms and unclassified focal epilepsy.
Focal cortical dysplasia
A key feature of GATOR1 disease is the association with focal cortical dysplasia, especially FCD type II.
This demonstrates that a germline genetic cause and a focal structural lesion are not mutually exclusive.
The two-hit model
In some people, an inherited germline GATOR1 variant may be followed by a second somatic event in a small group of brain cells.
This can help explain why one focal cortical region becomes abnormal while the rest of the brain does not.
Hemimegalencephaly and polymicrogyria
More extensive mTOR-pathway disruption can be associated with larger malformations including hemimegalencephaly and polymicrogyria.
EEG
EEG typically shows focal abnormalities corresponding to the individual’s seizure network.
Different relatives may have different EEG localisations.
MRI
MRI can be normal or show focal cortical dysplasia or other malformations.
Dedicated epilepsy-protocol MRI and expert neuroradiology review are important because subtle lesions can be missed.
Inheritance
GATOR1-related epilepsies are usually autosomal dominant with incomplete penetrance.
An unaffected parent can therefore carry and transmit a pathogenic variant.
SUDEP
SUDEP has been reported in GATOR1 families, particularly in people with uncontrolled bilateral tonic-clonic seizures.
The gene result itself does not allow individual risk prediction, but standard SUDEP counselling and seizure optimisation remain important.
Treatment
Antiseizure treatment follows focal epilepsy principles.
Some people respond well to medication, while others develop drug-resistant epilepsy.
Epilepsy surgery
When a focal cortical dysplasia or well-defined epileptogenic zone is identified, epilepsy surgery can be highly relevant.
A germline genetic diagnosis should not automatically exclude surgical evaluation.
mTOR inhibitors
Because GATOR1 disorders activate the mTOR pathway, mTOR inhibitors are biologically attractive treatments.
However, they are not established routine therapy for DEPDC5/NPRL2/NPRL3 epilepsy outside specific indications or research settings.
Genetic testing
Testing should be considered in familial focal epilepsy, focal epilepsy with variable localisation across relatives, and some cases of focal cortical dysplasia.
Broad sequencing can detect DEPDC5, NPRL2 and NPRL3, but low-level brain-limited somatic variants may require testing of resected tissue.
Worldwide access
Diagnosis may require both advanced MRI and genomic testing, creating barriers in lower-resource settings.
Brain-tissue sequencing is available only in specialised centres.
The central point
GATOR1 epilepsies show that genetic and structural epilepsy can be two parts of the same disease mechanism. A germline mTOR-pathway variant can predispose to a focal cortical lesion and a surgically treatable seizure network.
Related reading
Familial Focal Epilepsy with Variable Foci →
Focal Cortical Dysplasia →
Epilepsy Surgery and Presurgical Assessment →
Sources
Medical note: mTOR-targeted therapy for GATOR1 epilepsy remains investigational and should not replace established epilepsy treatment or surgical assessment.
Evidence checked: September 2026.