Rett Syndrome is most often caused by a spontaneous mutation in a gene called MECP2, on the X chromosome.

This gene makes a protein, also called MeCP2 (but written differently), which is necessary for normal brain function.

It is not hereditary and can occur in any family at any time. It affects around 1:10,000 live female births.

Research has shown that girls with Rett do not have brain damage. They know and understand much more than their bodies allow them to show – but they are locked in, trapped by a body that cannot obey signals from their brain.

Whilst there is currently no treatment for Rett Syndrome, there is hope.

In 1999 scientists identified the genetic mutation that causes Rett Syndrome. In 2007, they unexpectedly reversed the condition in mouse models of even late stage disease.