Molecular genetics of Rett syndrome

Rett syndrome is a neurodevelopmental disorder affecting almost exclusively females. It affects approximately one in 15 000 females and is characteriz ed by a loss of purposeful hand use, autism. ataxia and seizure. The disord er is usually sporadic, but rare familial cases have also been reported. Re cently it has been shown that familial cases are an X-linked dominant disor der and the disease locus maps to Xq28. A candidate gene called methyl-CpG- binding protein 2 was identified from the Xq28 region and was shown to cont ain mutations in about 77% of Rett syndrome patients. Since the encoded pro tein was previously shown to be a global transcriptional repressor, undesir ed expression of yet unidentified genes that are normally repressed is cons idered to be pathogenic in Rett syndrome. (C) 2001 Elsevier Science Ltd. Al l rights reserved.