Scientists reverse Rett syndrome symptoms in mice

New research recently published in the journal Science provides hope for the treatment of Rett syndrome, a rare but severe childhood neurological disorder.

Nearly 10,000 children in the UK are affected by Rett syndrome which, in its early stages, has similar symptoms to autism. The condition, which mainly affects girls, develops in early childhood and causes tremors, impaired speech and breathing problems as well as difficulty in movements such as walking. The disorder was previously thought to be untreatable.

Rett syndrome is caused by mutations in the MECP2 gene, which codes for a protein that can act as a biochemical switch to tell other genes, in this case those involved in nerve development, to turn off and stop producing their own proteins. The research, funded by the Rett Syndrome Research Foundation, was carried out at the University of Edinburgh in Scotland and used mice which had been genetically altered to have an inactive from of the MECP2 gene. Restoration of fully functional MECP2 over a four week period eradicated tremors and normalised breathing and mobility.

Professor Adrian Bird, Director for the Wellcome Trust Centre for Cell Biology at Edinburgh, who led the research, said, 'Like many other people, we expected that giving MECP2 to mice that were already sick would not work. The idea that you could put back an essential component after the damage to the brain is done and recover an apparently normal mouse seemed farfetched, as nerve cells that developed in the absence of a key component were assumed to be irrevocably damaged. The results are gratifyingly clear, and must give hope to those who are affected by this distressing disorder'.

Mutations in MECP2 have also been identified in some cases of childhood schizophrenia, classic autism and learning disabilities. Although this research is still in its early stages, the successful restoration of normal function demonstrated in the mouse models suggests that it may be possible to develop therapies to address the loss of MECP2 and potentially reverse neurological damage in children and adults with Rett Syndrome, autism and related neuropsychiatric disorders.