The authors conducted an epidemiologic survey in Utah using a four-
level ascertainment system, blind current diagnostic assessments, and
DSM-III criteria. Of 483 individuals ascertained, 241 were diagnosed as
having autism. The best estimate for the prevalence rate was 4 per 10,000
population. Autism was not associated with parental education, occupation,
racial origin, or religion. Sixty-six percent of the autistic subjects
scored below 70 on standardized IQ tests, and females scored
proportionately lower than males. Twenty (9.7%) of 207 families had more
than one autistic sibling, which supports the authors' previous finding
that there may be a familial subtype of autism.Abstract Teaser