Although KAT6A variants should be considered in the differential diagnosis of neonates presenting with complex multisystem presentations including cardiac and neurological symptoms accompanied by dysmorphic features, clinicians should be aware that a definitive causal relationship between specific neonatal manifestations (such as arrhythmias or seizures) and KAT6A variants remains unestablished and requires validation through larger-scale studies. Here, KAT6A is linked to cardiac arrhythmia.