Converging signalling disruptions: a threshold for Down syndrome hearts

This research explores why approximately 50% of children with Down syndrome develop heart defects by examining how multiple chromosome 21 genes, particularly the chromatin regulator HMGB1, collectively disrupt several critical developmental signaling pathways (BMP, Wnt, Notch, and calcineurin-NFAT). The authors propose a convergent threshold model suggesting that cumulative disruption of these pathways exceeds a critical level necessary for normal cardiac development.