New Insights into the Relation between Cognition, Behavior, and the CHD5 Gene: A Case-Report of an Adult Male with Parenti-Mignot Neurodevelopmental Syndrome.

Introduction: Parenti-Mignot neurodevelopmental syndrome is caused by pathogenic variants of the CHD5 gene - involved in brain development - and is characterized by developmental delay, intellectual disability, and behavioral disturbances (i.e., autism spectrum disorder or related social problems, obsessive-compulsive tendencies, and aggressive behavior) as well as subtle facial dysmorphisms, epilepsy, hypotonia, and craniosynostosis. To date, cognition, behavior, and psychopathology in patients are either scarcely studied (in children, adolescents, and young adults) or not studied at all. Therefore, this case report aimed to provide additional insights into the cognitive and behavioral phenotype of Parenti-Mignot neurodevelopmental syndrome and discuss possibilities for support and treatment. Case Presentation: This study presents the case of a 54-year-old male with Parenti-Mignot neurodevelopmental syndrome (nonsense variant in the CHD5 gene), who struggles with mood problems and aggressive behaviors. Intelligence, cognitive functioning, and psychopathology are described by using neuropsychological assessment. Moderate to mild intellectual disability was found. Levels of adaptive functioning and performance on measures of attention, executive functioning, and memory were within the expected range considering intelligence level, whereas social cognition constituted a weakness within the profile. Additionally, results indicated internalizing and externalizing behavioral problems and deficits in emotion regulation skills. Conclusion: It is hypothesized that behavioral disturbances of patients with the Parenti-Mignot neurodevelopmental syndrome are likely to result from an underlying cognitive profile that is characterized by low intelligence, social cognitive impairments, and poor emotion regulation. CHD5 involvement in cortical brain development may be an explanation for these cognitive deficits. In clinical practice, neuropsychological assessment can provide helpful pointers for treatment and support in daily functioning.