Dragonfly Study: An International, Prospective, Longitudinal, Observational Natural History Study of Children and Adults Living With CTNNB1 Neurodevelopmental Syndrome

CTNNB1 syndrome is a rare debilitating neurodevelopmental disorder caused by mutations in the CTNNB1 gene, which is characterised by developmental delay and intellectual disability. Due to its relatively recent discovery, very little is known about the natural history of the condition. The aim of the Dragonfly study is to characterise and monitor the neurodevelopment of children and adults diagnosed with CTNNB1 syndrome through an international collaborative effort. This study is being conducted across several countries, including Slovenia, Spain, Brazil, the USA, and Australia.

In this natural history study, tinvestigators aim to recruit 150 children or adults of any age and phenotype with a confirmed genetic diagnosis of CTNNB1 syndrome, and their primary carers. Investigators will invite the participant and their carers to attend an annual study visit over a period of 5 years, during which investigators will collect retrospective and prospective clinical data. This will include a clinical neurological examination and assessments of motor and cognitive function, communication, behaviour, vision, sleep, assessment of gait using actimetry, and recordings of brain activity using electroencephalography (EEG). Investigators will also assess results of retinal assessment using Optical Coherence Tomography, and structural brain assessments using magnetic resonance imaging (MRI) - these diagnostic procedures will be performed in the participant's home county and not on site. Blood tests will be performed to reconfirm the underlying mutations in the CTNNB1 gene and investigate biomarkers of the condition. Carers will also be invited to complete questionnaires exploring their child's/dependent's abilities and the impact of the condition on their family's quality of life.

There is currently no curative treatment available for CTNNB1 syndrome. However, pre-clinical studies have been successfully completed with promising results and genetic therapies are currently in development. A comprehensive understanding of the natural progression of the condition is essential prior to commencing clinical trials of potential treatments. By improving our understanding of CTNNB1 syndrome, this study aims to lay the foundation for future clinical trials and the development of targeted treatments.