In a population-based psychiatric study of 28 patients with tuberous sclerosis (TS) at the University of Goteborg, Sweden, 24 had autistic symptoms and 17 met all DSM-III-R criteria for autistic disorder (AD). Of the 17 with AD, 7 were severely mentally retarded, 7 had mild retardation, 3 were near average IQ, and 11 had ADHD. One girl of average IQ had Asperger syndrome. Only 3 were free of psychiatric/behavioral problems, all having average IQs. Of the 24 with autistic behavior, 14 had a history of infantile spasms. Infantile spasms were not specifically associated with later development of autistic behavior. TS predisposes to both autism and infantile spasms. Nine per cent of all children and 20% of females with autism may have TS. Autistic behavior in children < 5 years of age has a stronger correlation with TS than facial angiofibromas, a sign often not clearly defined until later childhood. 
COMMENT. An epidemiological study of TS in Western Sweden by the same authors showed a peak prevalence of 1 in 6800 in the 11 to 15 year-old age group, almost double that reported in earlier studies. In the whole cohort, 0-20 years, the prevalence was 1 in 12900.