Table 2. High-confidence risk genes for NDDs by functional category.

Functional category	Representative genes	Associated NDDs	Mutation type
Synaptic function	SHANK3, DLG4, NRXN1, STXBP1, SCAMP5	ASD, ID, epilepsy	De novo LoF, CNV
Ion channel function	SCN2A, KCNQ2, CACNA1I, GRIN2B, KCNB1	Epilepsy, ASD, ID	Gain/LoF, missense
Chromatin remodeling	CHD8, KMT5B, EP400, BRPF1, SETD1A	ASD, ID, epilepsy	LoF, missense
Transcriptional regulation	TCF7L2, FEZF2, FOXP1, ZMYND11	ASD, ID, ADHD	De novo LoF
Neuronal migration & axon guidance	TUBG1, MAPK8IP3, MARK2, EPHA7, DCC	ID, epilepsy, microcephaly	Missense, CNV

This table summarizes representative high-confidence risk genes for NDDs according to their primary biological function. Genes were selected based on meta-analyses of large-scale exome and genome sequencing studies. Functional categories include synaptic transmission (postsynaptic scaffolds, vesicular trafficking), ion channel activity (sodium, potassium, calcium channels), chromatin remodeling and histone modification, transcriptional regulation, and neuronal migration/axon guidance. Mutation types are indicated as de novo LoF, missense, or CNVs. ADHD, attention-deficit/hyperactivity disorder; ASD, autism spectrum disorder; CNV, copy number variation; ID, intellectual disability; LoF, loss-of-function; NDD, neurodevelopmental disorder.