© Anästh Intensivmed 2018. Rett syndrome is a rare inherited neurodevelopmental disease originally described by Andreas Rett in 1966, which occurs mostly in girls  and causes developmental and nervous system problems. Genetically, Rett syndrome results from mutations in the genes encoding methyl-cytosine-guanosine (CpG) binding protein 2 (MECP2) located on the X chromosome. In less than 10% of RTT cases, mutations in the genes CDKL5 or FOXG1 have also been found to resemble it . Affected individuals have clinical features that overlap with autism. Infants with Rett syndrome seem to grow and develop normally in the early months. However, between 6 and 18 months and 3 years of age development stagnates and they begin to lose previously attained skills.