Gabra2, encoding the GABAA α2 subunit, is a gene crucial for the function of GABAA receptors. These receptors are involved in the GABAergic signaling pathway, with GABA being the most important inhibitory neurotransmitter in the brain, playing a significant role in maintaining the balance between neuronal excitation and inhibition [3]. Genetic models, especially mouse models, have been instrumental in studying Gabra2's functions.

In mouse models, Gabra2 has been identified as a genetic modifier in multiple epilepsy-related conditions. In Scn1a+/- mice (a model for Dravet syndrome), repair of a B6-specific deletion in Gabra2 restored normal expression levels, increased the abundance of α2-containing GABAA receptors in hippocampal synapses, and rescued epilepsy phenotypes, validating Gabra2 as a genetic modifier of Dravet syndrome [1]. In Scn8a encephalopathy mouse models, the SJL/J strain's wild-type allele of Gabra2 delays seizure onset and extends lifespan, while the hypomorphic variant in C57BL/6J is associated with early seizure onset and short lifespan. Correction of the hypomorphic Gabra2 splice site variant in C57BL/6J mice modifies the severity of Scn8a encephalopathy [2,4].

In conclusion, Gabra2 is essential for the proper function of GABAA receptors in the GABAergic signaling pathway. Mouse models, including gene-knockout or-corrected models, have revealed its role as a genetic modifier in Dravet syndrome and Scn8a encephalopathy, highlighting its significance in understanding the pathogenesis of these epilepsy-related disorders and suggesting potential therapeutic strategies targeting α2-containing GABAA receptors [1,2,4].

References:

1. Hawkins, Nicole A, Nomura, Toshihiro, Duarte, Samantha, Contractor, Anis, Kearney, Jennifer A. 2021. Gabra2 is a genetic modifier of Dravet syndrome in mice. In Mammalian genome : official journal of the International Mammalian Genome Society, 32, 350-363. doi:10.1007/s00335-021-09877-1. https://pubmed.ncbi.nlm.nih.gov/34086081/

2. Yu, Wenxi, Hill, Sophie F, Xenakis, James G, Wagnon, Jacy L, Meisler, Miriam H. 2020. Gabra2 is a genetic modifier of Scn8a encephalopathy in the mouse. In Epilepsia, 61, 2847-2856. doi:10.1111/epi.16741. https://pubmed.ncbi.nlm.nih.gov/33140451/

3. Feng, Yan, Wei, Zi-Han, Liu, Chao, Zhang, Chu-Chu, Deng, Yan-Chun. 2022. Genetic variations in GABA metabolism and epilepsy. In Seizure, 101, 22-29. doi:10.1016/j.seizure.2022.07.007. https://pubmed.ncbi.nlm.nih.gov/35850019/

4. Yu, Wenxi, Mulligan, Megan K, Williams, Robert W, Meisler, Miriam H. 2021. Correction of the hypomorphic Gabra2 splice site variant in mouse strain C57BL/6J modifies the severity of Scn8a encephalopathy. In HGG advances, 3, 100064. doi:10.1016/j.xhgg.2021.100064. https://pubmed.ncbi.nlm.nih.gov/35047853/