Three individuals with mutations in the KAT5 gene have been reported and diagnosed with Neurodevelopmental disorder with dysmorphic facies, sleep disturbance, and brain abnormalities (NEDFASB). NEDFASB is transmitted in an autosomal dominant manner which means that only one copy of the gene must carry the mutations for the disease to occur. It is characterized by global developmental delay (delay in learning skills compared to other children), intellectual disability, behavioural anomalies, seizures, and sleep disturbance.