POGZ and Global developmental delay: A potential explanation may be that NMD of the aberrant mRNAs resulted in haploinsufficiency of the POGZ protein, but the rest of the normal mRNAs were translated and could compensate for this loss, thus resulting in a milder phenotype with less dysmorphic features and more mild neurocognitive impairment, such as developmental delay, borderline-mild intellectual disability and behavioral issues, than structural malformations of the brain or other organ systems.