The sex chromosomes--one key to autism? An XYY case of infantile autism.

Genetic/chromosomal factors have recently been proposed as being of importance in many children presenting with the behavioral syndrome of infantile autism. There are several single case studies in the literature of childhood psychosis in connection with the XYY syndrome. A further case of this combination is described. It is suggested that the sex chromosomes may be of major importance in the genesis of some cases of autism.