Genetics of the GABA-A Receptor in Epilepsy

GABA. Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter of the central nervous system. The main function of GABA is to reduce the excitability of neurons, which is the opposite of the excitatory glutamate that we described more extensively on our blog when talking about GRIN– and GRIA-related disorders. Many variants in GABA receptors are linked to epilepsy. Here, we will dive specifically into the genetics of the GABAA receptor.

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GRIA-related disorders – a different side of glutamate receptor dysfunction

GRIA genes. This is the first time we are describing GRIA genes on this blog. GRIA genes, which include GRIA1, GRIA2, GRIA3, and GRIA4, encode the AMPA receptor, one of the two key channels in the process of glutamate neurotransmission. While GRIN genes, which encode the NMDA receptor, have been characterized much more extensively in the literature, GRIAs remain relatively under-characterized, even though their protein products are involved in a similar molecular process in the post-synapse in modulating excitatory synaptic transmission. Here, we provide a brief overview of the genetic and phenotypic range of GRIA-related disorders.

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SYT1-related disorder: a neurodevelopmental SNAREopathy

SYT1. To continue our series on SNAREopathies—developmental disorders caused by genes encoding proteins involved in the SNARE complex—we next provide a brief overview of SYT1-related disorders. The gene SYT1 encodes synaptotagmin-1 (SYT1), which belongs to the group of synaptotagmin proteins that are essential for neurotransmission. Disease-causing mutations in SYT1 have a spectrum of clinical presentations ranging in severity and phenotypic complexity but also with certain unifying features, making SYT1-related disorders a complex neurodevelopmental SNAREopathy.

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