SCYL2, a member of the SCY1-like pseudokinase family, is involved in multiple biological processes. In eukaryotes, it regulates secretory protein trafficking, especially in the context of clathrin-mediated vesicle trafficking. This function is crucial for normal cellular activities, and its role in the nervous system is particularly significant as it suppresses excitotoxicity in the developing brain [1,2,3,5].

In mouse models, Scyl2 knockout leads to excess prenatal mortality, and surviving mice show severe neurological dysfunction. Specifically, there is a degeneration of several neuronal populations, most notably CA3 pyramidal neurons of the hippocampus during its functional maturation, which is due to a BAX -dependent apoptotic process caused by excessive excitatory signaling [2]. In humans, bi-allelic loss-of-function variants in SCYL2 are associated with arthrogryposis multiplex congenita-4 (AMC4), characterized by severe arthrogryposis, corpus callosum agenesis, epilepsy, and often early death [1,4].

In conclusion, SCYL2 is essential for the normal functioning of the nervous system, mainly by suppressing excitotoxicity. Studies using Scyl2 knockout mouse models have significantly contributed to understanding its role in neurological disorders like AMC4, highlighting its importance in maintaining normal neural development and function.