Three components of human brain gene expression reflect normative developmental programmes with specific links to neurodevelopmental disorders
Human brain organisation emerges from the coordinated transcription of thousands of genes, and the first principal component (C1) of spatial whole genome expression was shown to reflect cortical hierarchy. Here, optimised processing of the Allen Human Brain Atlas revealed two new components of brain transcription, C2 and C3, which were distinctively enriched for neuronal, metabolic and immune processes, cell-types and cytoarchitecture, and genetic variants associated with intelligence. Using additional datasets (PsychENCODE, Allen Cell Atlas, and BrainSpan), we found that C1-C3 represent generalisable transcriptional programmes that are coordinated within cells, and differentially phased during foetal and postnatal development. Autism spectrum disorder and schizophrenia were specifically associated with C1/C2 and C3, respectively, across neuroimaging, gene expression, and genome-wide association studies. Evidence converged especially in support of C3 as a normative transcriptional programme for adolescent brain development, which can lead to atypical supragranular brain connectivity in people at high genetic risk for schizophrenia.