Rett Syndrome is an X-linked autosomal disease and clinical signs vary according to the gender. The disease may follow a classic or atypical course in girls and patients get difficulties in learning.

It can also be characterized by the loss of language and motor skills acquired within the first 6-18 months and stereotypic movements of the hands, microcephaly, seizures and mental retardation. It continues much severe in males.

MECP2 gene causing the disease has localized on the long arm of X chromosome (Xq28) with 4 exons.