Svetlana Vorsanova, Yuri Yurov, Moscow Brain Institute, Russia Rett syndrome is a developmental disorder, affecting girls.
Some clinical signs are present from early infancy, and probably in the prenatal period.
The etiology of RS is unknown, but genetic factors are important. RS is commonly thought of as an X-linked dominant disorder lethal to hemizygous males. However, at the present time its biological and genetic basis remains obscure. The aim of the present work is to combine classical and modern molecular-cytogenetic methods to the study of genetics of Rett syndrome and development of method for preclinical diagnosis of this disease. Im S S Korsakova.