Fresh insight into an autism spectrum disorder could aid the search for treatments for the condition.
Scientists investigating Rett syndrome, which affects more than 1,000 girls in the UK, believe the biological mechanism behind the disorder may be simpler than was previously thought.
Researchers at the University of Edinburgh found that a faulty protein which causes the condition interacts with all the genes in brain cells.
This contradicts previous thinking that the protein affected only a handful of genes.
The discovery suggests that impact of the faulty gene, known as MeCP2, may be similar in different types of brain cells.
Symptoms of Rett syndrome, which affects mainly girls, develop at around one year of age.
They include poor communication skills and reduced mobility. Those affected may also suffer seizures, digestive and breathing problems and often need constant care.
The study, funded by the Wellcome Trust, was published in the journal Molecular Cell.
It may be that, in Rett patients, many brain cells share a generic defect – which would mean this disease is less complicated than we feared. More work is needed to investigate this possibility.