[Clinical and molecular genetic findings in four girls with Rett syndrome].

We report on four mental retarded girls with typical clinical signs of Rett syndrome. Rett syndrome is an X-linked neurodevelopment disorder which develops after a period of normal development at the age of 6 to 18 months, affecting 1/10 000 - 15 000 girls. Recently, the MeCP2-gene encoding the methyl-CpG-binding protein 2 has been shown to be mutated in 80 percent of girls with Rett Syndrome, studied so far. In our patients with Rett syndrome two common mutations of the MeCP2-gene, R168X (n=2) and T158M were found. In the 4th patient a novel "missense" mutation R294G was identified.