Disruption of Nipbl/Scc2 in Cornelia de Lange Syndrome provokes cohesin genome-wide redistribution with an impact in the transcriptome

Cornelia de Lange syndrome (CdLS) is a rare disease affecting multiple organs and systems during development. Mutations in the cohesin loader, Nipbl/Scc2 were first described and are the most frequent in clinically diagnosed CdLS patients. The molecular mechanism driving the CdLS phenotypes are not understood. Apart from its canonical role in sister chromatid cohesion, cohesin has also been involved in the regulation of the spatial organization of the genome. Here, we investigated the transcriptome of CdLS-derived primary fibroblasts (gene expression microarray data included in the manuscript as an excel file) and observed the downregulation of genes involved in development and system skeletal organization providing a link to the developmental alterations and limb abnormalities characteristics of the CdLS patients. Genome-wide distribution studies demonstrated a global reduction of Nipbl at the Nipbl-associated high GC content regions in CdLS-derived cells. In addition, cohesin accumulates at Nipbl-occupied sites at CpG islands probably due to reduced cohesin translocation along chromosomes and fewer cohesin peaks colocalize with CTCF. Overall design: ChIP-seq from control and CdLS patients