Rett syndrome (RTT) is one of the most common causes of intellectual and developmental disabilities in girls, and is caused by mutations in the gene encoding methyl-CpG binding protein 2 (MECP2).
Methyl-CpG-binding protein 2 (MECP2) deleterious variants, which are responsible for Rett syndrome in girls, are involved in a wide spectrum of developmental disabilities in males.
Numerous mutations in DNMTs, TETs and MeCP2 have been identified in cancer and developmental disorders, highlighting the importance of the DNA methylation machinery in human development and physiology.
The FOXG1 gene was sequenced in 210 patients, including 129 patients with unexplained developmental disorders and 81 MECP2 mutation negative individuals.
Mutations in MECP2 gene account for approximately 80% of cases of Rett syndrome (RTT), an X-linked severe developmental disorder affecting young girls, as well as for most cases of Preserved Speech Variant (PSV), a mild RTT variant in which autistic behavior is common.