The role of the activity of neurotrophins such as BDNF for brain development has long been recognised but its deficit in many neurological conditions is more recently studied. Substantial evidence is accumulating that supports the role of environmental enrichment in improving functional outcomes in conditions such as Parkinson’s, Alzheimer’s and Huntington’s disease, and there is evidence that the effect is mediated by BDNF. In Rett syndrome, mouse studies since 2008 have found similarly: that an enriched environment that includes physical activity improves functional abilities, and that this improvement is accompanied by increased levels of BDNF. There is now an urgent need to investigate these same variables in children – a group who suffer marked impacts on their ability to participate in daily life and who desperately need evidence-based treatments. If findings in humans are similar to the mouse studies, then clear guidance on use of an environmental enrichment intervention will be possible with outcomes of improved child health and wellbeing. There are few therapy services in China and therefore very little contamination. Beyond Rett syndrome, testing the role of exercise in improving neural pathways and brain function will be a model for other childhood neurodevelopmental disorders.
We will be the first to measure blood levels of BDNF as an outcome measure in genetically characterised children with Rett syndrome. This will complement our other outcomes that will include functional abilities, physical activity, parent perceptions of severity of concerns, and other aspects of health and wellbeing. We will also be the first to include the polymorphism status of the BDNF gene in our analyses as an effect modifier.