De novo mutations in schizophrenia implicate synaptic networks.

Area of Science:

• Neurogenetics
• Molecular Psychiatry
• Synaptic Biology

Background:

• Schizophrenia risk is primarily attributed to inherited genetic factors.
• Large de novo mutations (copy number changes) affect a small subset of patients, disproportionately impacting postsynaptic protein genes.
• The role of small de novo mutations in schizophrenia pathogenesis remains less understood.

Purpose of the Study:

• To investigate the enrichment of small de novo mutations in specific synaptic protein complexes in schizophrenia.
• To identify synaptic pathways and genes affected by these mutations.
• To explore shared etiological mechanisms between schizophrenia and other neurodevelopmental disorders.

Main Methods:

• Analysis of small de novo mutations in genes encoding glutamatergic postsynaptic proteins.
• Identification of mutations in proteins interacting with activity-regulated cytoskeleton-associated protein (ARC) and N-methyl-d-aspartate receptor (NMDAR) complexes.
• Comparison of mutation-enriched genes and pathways with those in autism and intellectual disability.

Main Results:

• Small de novo mutations are overrepresented in genes encoding ARC and NMDAR complex proteins.
• Enrichment of mutations was observed in proteins regulating actin dynamics and targets of fragile X mental retardation protein (FMRP).
• Genes and synaptic pathways affected by mutations in schizophrenia overlap with those in autism and intellectual disability.

Conclusions:

• Small de novo mutations contribute to schizophrenia risk by disrupting critical postsynaptic and synaptic plasticity mechanisms.
• The findings highlight shared genetic and molecular pathophysiology underlying schizophrenia and other neurodevelopmental disorders.
• This research provides reproducible insights into the etiological mechanisms of schizophrenia.