Rett syndrome is a progressive neurodevelopmental disorder, primarily affecting females. Rett syndrome is characterized by acquired microcephaly, loss of purposeful hand movements, and autistic behaviors, following a period of normal growth and development. Rett syndrome is caused by mutations in the MeCP2 (methyl-CpG-binding protein) gene located at Xq28. Sequence mutations are present in 80% of girls with classic Rett syndrome and 20% of girls with a variant diagnosis. MeCP2 deletions are found in approximately 16% of girls with classic Rett syndrome and no previously identified sequence mutation.
Deletions and/or duplications in the MECP2 gene as causative of Rett syndrome have been reported.