CYFIP2, a component of the WAVE regulatory complex, plays a crucial role in regulating actin dynamics and synaptic function. Through genetic analysis of patients diagnosed with Early Infantile Epileptic Encephalopathy (EIEE), novel mutations in the CYFIP2 gene were identified. Functional studies revealed altered synaptic plasticity and neuronal excitability associated with these mutations. Furthermore, behavioral assays in animal models harboring CYFIP2 mutations demonstrated phenotypes consistent with epileptic encephalopathy. These findings underscore the significance of CYFIP2 in neuronal development and highlight its potential role in the pathogenesis of EIEE. In this study, we focused on understanding the molecular mechanisms underlying CYFIP2 Arg87Cys mutation. To analyse the effects of Arg87Cys mutation in actin dynamics and cell morphology, we used the neuroblastoma cell line SH-SY5Y, and performed wound healing assay, cell tracking and neurite length measurement; furthermore, to investigate possible alteration in spine density and axon growth we used primary neuronal cell culture. Finally, we performed an overall analysis of signal transduction pathway by using a massively promoter reporter assay (MPRA) which can be useful to investigate pathways by monitoring the activity of transcription factors. Changes in reporter gene expression can indicate a different activation or inhibition pattern of specific signalling pathways.