WASF1 (WASP family member 1) is a key effector protein that mediates signal transduction from receptor tyrosine kinases and small GTPases to the actin cytoskeleton 1. As a core component of the WAVE regulatory complex (WRC), WASF1 promotes actin filament polymerization and lamellipodia formation through cooperation with the Arp2/3 complex 2. Beyond cytoskeletal regulation, WASF1 participates in BDNF-NTRK2 endocytic trafficking and mitochondrial dynamics 1. Pathogenic WASF1 variants cause neurodevelopmental disorder with absent language and variable seizures (NEDALVS), an autosomal dominant condition characterized by severe developmental delay, intellectual disability, seizures, hypotonia, and microcephaly 34. Both truncating variants and missense mutations, particularly hotspot mutations at p.Trp161, have been identified 3. NEDALVS represents the primary clinical association with WASF1 dysfunction 56, though WASF1 loss-of-function has been noted in prostate cancer contexts 7. Clinically, WASF1-related NDD presents a spectrum from moderate-to-profound intellectual disability with autism and epilepsy, to milder phenotypes 6. Motor and language developmental delays occur universally, with seizures in ~65% of cases 4. Exome sequencing enables molecular diagnosis in resource-limited settings 5, making genetic confirmation essential for NEDALVS diagnosis and family counseling.