Clinical recognition of Rett syndrome.

Key manifestations helpful in diagnosing Rett syndrome include progressive loss of previously acquired psychomotor skills, apraxia with loss of use of hands and legs, and "handwashing" automatisms. Four types of clinical presentation can be described: a neurodegenerative disorder, an autistic syndrome, a Lennox-Gastaut syndrome, and a chronic encephalopathy. Carbamazepine currently appears to be the anticonvulsant of choice. The mild lactic and pyruvic acidosis along with the ultrastructural abnormalities of mitochondria in brain and liver biopsies point to a generalized disorder of energy metabolism.