Autism and autism risk in siblings of children with specific language impairment.
BACKGROUND
Several studies have shown that family members of children with autism have elevated rates of spoken and written speech and language problems.


OBJECTIVE
This study asked whether there was also a greater rate of siblings with autism among probands with specific language impairment.


METHODS
The probands in this study were 158 children with specific language impairment and 132 children with normal language status. These probands had 522 siblings who were examined for risk of autism using the Autism Behavior Checklist. Siblings found to be at risk were then examined using the Autism Diagnostic Interview--Revised and the Autism Diagnostic Observation Schedule-G.


RESULTS
A concentration of siblings with risk for a diagnosis of autism was found in association with probands who had poor spoken language skills. Four siblings of the 522 (0.8%) met the diagnostic standards for autism. All the probands of these siblings had spoken language scores below -1 SD and three had diagnoses of spoken language impairment.


CONCLUSIONS
These data provide additional support for a familial association between autism and spoken language impairment.
Tomblin
J Bruce
JB
Department of Speech Pathology and Audiology, University of Iowa, Ames 52242, USA. j-tomblin@uiowa.edu
Hafeman
Laura L
LL
O'Brien
Marlea
M
D001321:Autistic Disorder / Q000175:diagnosis / Q000235:genetics*; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D007805:Language Development Disorders / Q000175:diagnosis / Q000235:genetics*; D008137:Longitudinal Studies; D008297:Male; D012306:Risk; D035781:Siblings