Researchers studied four unrelated Chinese families in which a child had intellectual disability, identifying four different loss-of-function variants in the POGZ gene through whole-exome sequencing — three of which are newly described. RNA sequencing of the affected individuals revealed abnormal expression of 484 genes, with many involved in the formation and function of synapses (the connections between brain cells). The findings expand the known range of POGZ mutations linked to neurodevelopmental disorders and shed light on how POGZ haploinsufficiency may disrupt brain development at the molecular level.