ABSTRACT
The UCLA Registry for Genetic Studies in Autism was established in 1980 to test the hypothesis that genetic factors may be etiologically significant in subsets of patients. To date 61 pairs of twins have enrolled and 40 meet research diagnostic criteria for autism. The syndrome has been identified in all parts of the world and in all social classes and races without special distribution. It occurs three to four times more often in males and is frequently found in association with other syndromes such as epilepsy and mental retardation. Sixty-one families with twins enrolled in the registry between January 1980 and April 1984. Forty-seven provided sufficient records so that their children could be diagnosed in accordance with the research protocol. To assess the proportion of all twins with autism in the United States enrolled in the registry to date the authors followed the model published by S. Folstein and M. Rutter.
