Rett syndrome associated with tuberous sclerosis in a male and in a female: evidence for arrested motor and mental development.

Two sporadic cases of tuberous sclerosis presented with flexion spasms in a male and early intractable seizures evolving into a Lennox-Gastaut syndrome in a female. Early hypotonia and lack of substantial motor development are key features of the Rett syndrome, more easily overlooked than hand-wringing. Clumsy self-feeding and immature ambulation were the highest achievements in the second case now aged 36 years. Immaturity rather than degeneration, dementia, or assumed tissue destruction, is the capital feature of many disorders of early brain development leading to profound motor as well as mental retardation. Studying unusual clinical combinations is more likely to shed light on the underlying etiology than focusing on procrustean syndrome definitions.