Figure 2.

Functional convergence of representative NDD genes onto neural circuit dysfunction. This concentric diagram shows that hundreds of NDD-associated genes converge on a limited set of mechanisms. Outer ring: gene categories (ion channels, synaptic proteins, chromatin remodelers, transcription factors, splicing factors/noncoding RNAs). Middle ring: representative genes (SCN2A, SHANK3, CHD8, FEZF2, RNU4‑2). Inner ring: core disrupted mechanisms (altered excitability, synaptic defects, epigenetic dysregulation, abnormal developmental timing). Center: neural circuit dysfunction, the common final pathway to NDDs. This convergence supports targeting shared downstream mechanisms rather than individual genes. NDD, neurodevelopmental disorder.