[Cytogenetic and molecular genetic diagnostics of Rett syndrome in children]

Rett syndrome in 32 children (31 girls and 1 boy) was diagnosed according to International association on Rett syndrome. The phenomenon of the presence of special type of late-replicating chromosome X (type C) was revealed. This phenomenon may be recommended as a diagnostic test for both preclinical periods of development of the disease and in atypical cases of Rett syndrome.