A mutation in the Rett syndrome gene, MECP2, causes X-linked mental retardation and progressive spasticity in males.
Meloni I., Bruttini M., Longo I., Mari F., Rizzolio F., D'Adamo P., Denvriendt K., Fryns J.-P., Toniolo D., Renieri A.
Heterozygous mutations in the X-linked MECP2 gene cause Rett syndrome, a severe neurodevelopmental disorder of young females. Only one male presenting an MECP2 mutation has been reported; he survived only to age 1 year, suggesting that mutations in MECP2 are male lethal. Here we report a three-generation family in which two affected males showed severe mental retardation and progressive spasticity, previously mapped in Xq27.2-qter. Two obligate carrier females showed either normal or borderline intelligence, simulating an X-linked recessive trait. The two males and the two obligate carrier females presented a mutation in the MECP2 gene, demonstrating that, in males, MECP2 can be responsible for severe mental retardation associated with neurological disorders.