What causes Rett syndrome?
Rett syndrome results from a chain of events which begin with a genetic mutation at the time of conception.
In October 1999, it was discovered by researchers at the Baylor College of Medicine in Houston that mutations in the MECP2 gene are the main cause of Rett syndrome. To date, mutations in this gene have been found in 95% of individuals who have been diagnosed with the disorder. It is not known why these mutations occur.
The MECP2 gene contains instructions which enable genes to function properly. If the MECP2 gene is not functioning properly, it allows genes to turn on or off at inappropriate times, thus disturbing the precisely regulated sequence necessary for proper development of a human’s central nervous system.
In 2008, it was found that mutations in the FOXG1 gene also cause the syndrome but only in a very small number, namely, those persons diagnosed with Rett syndrome whose early development slowed or went backwards very soon after being born.