Normal Function
The NPRL2 gene provides instructions for making a protein that is one piece of a group of proteins (complex) called GATOR1. This complex is found in cells throughout the body, where it regulates a signaling pathway called the mTOR pathway. The mTOR pathway is involved in cell growth and division (proliferation), the survival of cells, and the creation (synthesis) of new proteins. The role of the GATOR1 complex is to block this pathway by inhibiting (stopping) the activity of a complex called mTOR complex 1 (mTORC1) that is integral to the mTOR pathway.
In the brain, the mTOR pathway regulates many processes, including the growth and development of nerve cells and their ability to change and adapt over time (plasticity).
Health Conditions Related to Genetic Changes
Familial focal epilepsy with variable foci
At least 6 NPRL2 gene mutations have been found to cause familial focal epilepsy with variable foci (FFEVF), which is an uncommon form of recurrent seizures (epilepsy) that runs in families. Most of these mutations lead to the production of an abnormally short, nonfunctional protein. As a result, formation of normal GATOR1 complex is reduced, leading to overactivity of mTORC1 and excessive signaling of the mTOR pathway. It is not clear how an abnormally active mTOR pathway leads to the seizures of FFEVF. Research suggests that increased mTOR pathway signaling in the brain leads to changes in the connections between nerve cells (synapses) and increased activation (excitation) of nerve cells, which can cause seizures.
More About This Health ConditionOther Names for This Gene
- NPR2
- NPR2-like protein
- NPR2-like, GATOR1 complex subunit
- NPR2L
- tumor suppressor candidate 4
- TUSC4
Additional Information & Resources
Tests Listed in the Genetic Testing Registry
Scientific Articles on PubMed
Catalog of Genes and Diseases from OMIM
References
- Baldassari S, Licchetta L, Tinuper P, Bisulli F, Pippucci T. GATOR1 complex: the common genetic actor in focal epilepsies. J Med Genet. 2016 Aug;53(8):503-10. doi: 10.1136/jmedgenet-2016-103883. Epub 2016 May 19. Citation on PubMed
- Baulac S. mTOR signaling pathway genes in focal epilepsies. Prog Brain Res. 2016;226:61-79. doi: 10.1016/bs.pbr.2016.04.013. Epub 2016 Jun 7. Citation on PubMed
- Weckhuysen S, Marsan E, Lambrecq V, Marchal C, Morin-Brureau M, An-Gourfinkel I, Baulac M, Fohlen M, Kallay Zetchi C, Seeck M, de la Grange P, Dermaut B, Meurs A, Thomas P, Chassoux F, Leguern E, Picard F, Baulac S. Involvement of GATOR complex genes in familial focal epilepsies and focal cortical dysplasia. Epilepsia. 2016 Jun;57(6):994-1003. doi: 10.1111/epi.13391. Epub 2016 May 13. Citation on PubMed
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