Decoding SCN2A Variants: Bridging Genetics and Phenotypes in Autism Spectrum Disorder

Background: Autism spectrum disorder (ASD) is a complex neurodevelopmental condition with a rising prevalence, driven by multifactorial genetic and environmental factors. Among the genetic contributors identified, SCN2A, a critical gene encoding the Nav1.2 sodium channel, has been implicated in ASD and other related neurological conditions. This systematic review aims to explore the relationship between SCN2A mutations and ASD phenotypes. Methods: This review systematically analyzed data from studies reporting SCN2A mutations in individuals diagnosed with ASD. The primary focus was on the characterization of mutation types, associated clinical features, and phenotypic variability. Results: The mutations identified were predominantly de novo missense mutations and were associated with a spectrum of neurological and developmental challenges, including seizures, intellectual disability, movement disorders, and repetitive behaviors. A notable finding was the significant phenotypic variability observed across individuals. Gender differences emerged, suggesting a potentially greater impact on females compared to trends typically seen in ASD genetic studies. Specific mutations, such as c.2919+4delT, and mosaicism were identified as novel contributors to the observed heterogeneity. Conclusions: The review highlights the clinical significance of SCN2A mutations in ASD and highlights their relevance in genetic counseling and the development of targeted therapies. Understanding the diverse genotype-phenotype correlations associated with SCN2A can drive progress in personalized medicine, paving the way for precision therapies tailored to individuals with SCN2A-related ASD.