MLL4-associated condensates counterbalance Polycomb-mediated nuclear mechanical stress in Kabuki syndrome

MLL4 (KMT2D) loss of function, as found in Kabuki syndrome, affects the chromatin compartmentalization of Polycomb proteins and changes the nuclear architecture. Inhibition of ATR reestablishes mechanosignaling of mutant mesenchymal stem cells and their commitment to becoming chondrocytes.