Abstract
Down syndrome (DS), caused by trisomy of chromosome 21, is the leading genetic cause of intellectual disability, yet the mechanisms disrupting fetal brain development remain unclear. We performed single-cell transcriptomic and chromatin accessibility profiling of approximately 250,000 cells from 15 DS and 15 control human fetal cortices (10-20 weeks postconception). Our analysis revealed a subtype-specific reduction in RORB- and FOXP1-expressing excitatory neurons and widespread disruption of neurodevelopmental transcriptional programs. Chromosome 21 transcription factors BACH1, PKNOX1 and GABPA emerged as dosage-sensitive hubs regulating genes linked to intellectual disability. Antisense oligonucleotide-mediated normalization of these transcription factors in human neural progenitors in vitro partially rescued target gene expression. Benchmarking a humanized in vivo model captured additional molecular and cellular signatures of DS, complementing the in vitro model. Together, we present a resource defining the gene-regulatory landscape underlying cortical development in DS and highlight molecular pathways for further investigation.
PMID:41545595 | DOI:
UK DRI Authors
