Two gene co-expression modules differentiate psychotics and controls.

Area of Science:

• Neuroscience
• Genetics
• Psychiatry

Background:

• Schizophrenia (SCZ) and bipolar disorder (BD) are highly heritable psychiatric disorders.
• Genetic and gene expression changes are implicated but often lack replication and functional understanding.

Purpose of the Study:

• To identify co-expression gene modules associated with SCZ.
• To investigate the functional roles of these modules in SCZ and BD pathogenesis.

Main Methods:

• Weighted gene co-expression network analysis (WGCNA) was employed to identify gene modules.
• Modules were tested for differential expression in patient versus control cohorts.
• Enrichment analysis was performed for biological functions and genetic signals.

Main Results:

• Two significant co-expression modules were identified: one upregulated in the cerebral cortex enriched with neuron differentiation/development genes and SCZ GWAS signals; the second altered in the cerebral cortex and cerebellum, enriched with neuron protection genes.
• These findings were robust across five independent datasets, including multiple brain regions and BD patient data.
• The identified modules and their associated functions were consistently observed across different platforms and patient groups.

Conclusions:

• Neuron differentiation and development pathways are implicated in the etiology of both SCZ and BD.
• Neuron protection functions play a role in the pathological processes of these disorders.
• Co-expression network analysis provides a powerful approach to uncover biologically relevant gene modules in complex psychiatric diseases.