Case Report: Prenatal imaging and genetic integrated diagnosis of SCN2A encephalopathy—a case of cryptical cortical dysplasia caused by a loss-of-function frameshift genetic variant

This is the first report of prenatal imaging phenotypes in <i>SCN2A</i> frameshift mutations, featuring persistent CSP narrowing and progressive focal cortical thickening. Distinct from missense mutation-related ventriculomegaly, it suggests potential mutation-specific signatures. Unexplained CSP narrowing/cortical thickening warrants sodium channelopathy suspicion, with <i>SCN2A</i> prioritized in fetal cortical malformation panels. Single-case limitations demand large-cohort validation for genotype-phenotype correlations.