Gabrg1-KO Mouse

GABRG1, encoding the γ1 subunit of the GABA-A receptor, is a crucial gene. The GABA-A receptor is involved in inhibitory neurotransmission, with GABA-A receptor-mediated signaling playing a vital role in the regulation of neuronal excitability in the central nervous system [1,2,3,5,6].

A novel de novo variant in GABRG1 was found in a 2-year-old patient with epileptic encephalopathy, hypotonia, and global developmental delays, suggesting it could be a potential novel cause of these conditions [1]. Multiple studies also indicate an association between GABRG1 and alcohol-related disorders. For example, in two population isolates, GABRG1 haplotypes and SNPs were significantly associated with alcohol use disorders (AUD), and in African Americans, haplotypes combining SNPs from GABRG1 and GABRA2 showed significant differences between alcohol-dependent subjects and controls [2,3]. Additionally, a SNP of GABRG1 was associated with level of response to alcohol and drinking patterns in non-treatment-seeking hazardous drinkers, and markers in the 5' GABRG1 haplotype showed greater association with alcohol dependence in European Americans [4,5]. There was also a significant GABRG1 genotype by lorazepam pretreatment interaction for cumulative work in a study on voluntary intravenous self-administration of alcohol [8]. Moreover, GABRG1 has been proposed as a possible contributor to the development of trigeminal neuralgia, though its role in familial cases still needs to be addressed [7].

In conclusion, GABRG1 is essential for normal neuronal function through its role in the GABA-A receptor. Studies, especially those on its association with alcohol-related disorders and its potential link to epileptic encephalopathy and trigeminal neuralgia, highlight its significance in understanding these disease mechanisms. However, more research, potentially including gene knockout or conditional knockout mouse models in the future, is needed to further clarify its functions in these disease areas [1,2,3,4,5,7,8].

References:

1. Williams, Aaron, Cooney, Erin, Segal, Gabrielle, Morand, Megan, Agadi, Satish. 2022. GABRG1 variant as a potential novel cause of epileptic encephalopathy, hypotonia, and global developmental delay. In American journal of medical genetics. Part A, 188, 3546-3549. doi:10.1002/ajmg.a.62969. https://pubmed.ncbi.nlm.nih.gov/36121006/

2. Enoch, Mary-Anne, Hodgkinson, Colin A, Yuan, Qiaoping, Virkkunen, Matti, Goldman, David. 2008. GABRG1 and GABRA2 as independent predictors for alcoholism in two populations. In Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, 34, 1245-54. doi:10.1038/npp.2008.171. https://pubmed.ncbi.nlm.nih.gov/18818659/

3. Ittiwut, Chupong, Yang, Bao-Zhu, Kranzler, Henry R, Farrer, Lindsay A, Gelernter, Joel. 2011. GABRG1 and GABRA2 variation associated with alcohol dependence in African Americans. In Alcoholism, clinical and experimental research, 36, 588-93. doi:10.1111/j.1530-0277.2011.01637.x. https://pubmed.ncbi.nlm.nih.gov/21919924/

4. Ray, Lara A, Hutchison, Kent E. 2009. Associations among GABRG1, level of response to alcohol, and drinking behaviors. In Alcoholism, clinical and experimental research, 33, 1382-90. doi:10.1111/j.1530-0277.2009.00968.x. https://pubmed.ncbi.nlm.nih.gov/19426171/

5. Covault, Jonathan, Gelernter, Joel, Jensen, Kevin, Anton, Raymond, Kranzler, Henry R. 2007. Markers in the 5'-region of GABRG1 associate to alcohol dependence and are in linkage disequilibrium with markers in the adjacent GABRA2 gene. In Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, 33, 837-48. doi:. https://pubmed.ncbi.nlm.nih.gov/17507911/

6. Ittiwut, Chupong, Listman, Jennifer, Mutirangura, Apiwat, Thavichachart, Nuntika, Gelernter, Joel. 2007. Interpopulation linkage disequilibrium patterns of GABRA2 and GABRG1 genes at the GABA cluster locus on human chromosome 4. In Genomics, 91, 61-9. doi:. https://pubmed.ncbi.nlm.nih.gov/17976953/

7. Mannerak, Mari Aaroe, Lashkarivand, Aslan, Eide, Per Kristian. . Trigeminal neuralgia and genetics: A systematic review. In Molecular pain, 17, 17448069211016139. doi:10.1177/17448069211016139. https://pubmed.ncbi.nlm.nih.gov/34000891/

8. Plawecki, Martin H, Wetherill, Leah, Vitvitskiy, Victor, Edenberg, Howard J, O'Connor, Sean. 2012. Voluntary intravenous self-administration of alcohol detects an interaction between GABAergic manipulation and GABRG1 polymorphism genotype: a pilot study. In Alcoholism, clinical and experimental research, 37 Suppl 1, E152-60. doi:10.1111/j.1530-0277.2012.01885.x. https://pubmed.ncbi.nlm.nih.gov/22817768/