DLG2 encodes a membrane-associated guanylate kinase (MAGUK) scaffold protein that serves critical roles in synaptic function and genome stability. As a postsynaptic density component, DLG2 regulates synaptic plasticity and is essential for normal neurodevelopment 1. The protein functions as a tumor suppressor, particularly in neuroblastoma, where it maintains genome integrity by impairing DNA double-strand break repair through NHEJ pathways and promoting p53-mediated apoptosis in response to genotoxic stress 2. DLG2 haploinsufficiency is strongly associated with neurodevelopmental psychiatric disorders including autism spectrum disorder, schizophrenia, and bipolar disorder 31. Intragenic deletions of DLG2, particularly in the 5' region around exon 8, cause developmental delays, congenital anomalies, and dysmorphism 3. In neuroblastoma, low DLG2 expression forces cell cycle progression and predicts poor patient survival, linking 11q-deleted and MYCN-amplified tumors 4. The gene also shows associations with Parkinson's disease risk in Chinese populations 5. DLG2 knockout disrupts transcriptional programs essential for cortical neurogenesis, affecting neuronal differentiation, migration, and maturation 6, highlighting its fundamental role in brain development and neuropsychiatric disease susceptibility.