What causes Rett syndrome?

Almost all cases of Rett syndrome are caused by a genetic mutation, which affects the MECP2 gene (methyl CPG binding protein 2). This gene was identified in 1999 by scientists and it is believed to control many other genes. The gene contains the instructions for the production of the protein, methyl cytosine binding protein 2, which is used for brain function and development; the protein also acts as a kind of switch, which is used to control the actions of other genes.

In people with Rett syndrome, the MECP2 gene does not work properly and this means that the protein produced is not structurally correct; most people with the syndrome also don’t produce enough of the protein.

The vast majority of cases of Rett syndrome are caused by spontaneous mutation; nobody knows why this happens and there does not appear to be any trigger in many cases. In some cases, Rett syndrome may affect people who have female family members with a mutated MECP2 gene (this does not necessarily mean they have Rett syndrome and they may display no symptoms); this is known as being an asymptomatic carrier.

In boys, the syndrome is very different; because boys only have one X chromosome, there is no protection against the syndrome and almost all die during pregnancy or during the first few days of their lives.

Rett Syndrome

• Rett Syndrome
• What causes Rett syndrome?
• Diagnosing Rett syndrome
• What are the symptoms of Rett syndrome?
• What are the effects of Rett syndrome?

• How is Rett syndrome treated?
• What is the outlook for people with Rett syndrome?
• Help for patients and carers