POGZ and neurodevelopmental disorder: The variable expressivity of this mutation, present in both the symptomatic father and asymptomatic sister, illustrates the nuanced relationship between genotype and psychiatric phenotype commonly observed in neurodevelopmental disorders.18 POGZ mutations disrupt chromatin remodelling during critical neurodevelopmental stages.8,28 potentially fostering a neurobiological vulnerability to severe psychiatric conditions, such as this patient’s catatonia, rather than directly triggering acute syndromes like catatonia itself.