[Rett syndrome--an odd handicap affecting girls. A current 25-year follow-up in Western Sweden].

Rett syndrome, a complicated neurodevelopmental disorder exclusively affecting girls in early childhood, is now known to be one of the major worldwide causes of severe mental retardation in females. Although internationally unknown until the mid-1980s, under another designation it had been observed in Sweden since the early 1960s. The article consists in a review of current clinical, neurobiological and genetic knowledge of the syndrome, and a systematic penetration of data collected from the follow-up of a west Swedish series of 54 female patients, 5-57 years of age. Mortality in the series was 17 percent, with a median age at death of 24 years. In most cases death was sudden and unexpected.