The authors recently reported, in this journal, an epidemiologic survey
of autism in Utah. Twenty (9.7%) of the 207 families ascertained had more
than one autistic child. Analyses of these data revealed that autism is 215
times more frequent among the siblings of autistic patients than in the
general population. The overall recurrence risk estimate (the chance that
each sibling born after an autistic child will develop autism) is 8.6%. If
the first autistic child is a male the recurrence risk estimate is 7%, and
if a female 14.5%. These new recurrence risk estimates should be made
available to all individuals who have autistic children and are interested
in family planning.Abstract Teaser