Autism Research Today is a free monthly online journal that collates and summarizes the latest research about Autism, including details on symptoms, diagnosis, treatment, causes, effects.

Intergenerational transmission of subthreshold autistic traits in the general population.

Constantino JN, Todd RD

Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA. constantino@wustl.edu

BACKGROUND: Autistic disorder (AD) is a disabling oligogenic condition characterized by severe social impairment. Subthreshold autistic social impairments are known to aggregate in the family members of autistic probands; therefore, we conducted this study to examine the intergenerational transmission of such traits in the general population. METHODS: The Social Responsiveness Scale (SRS), a quantitative measure of autistic traits, was completed on 285 pairs of twins (by maternal report) and on their parents (by spouse report). RESULTS: Correlation for social impairment or competence between parents and their children and between spouses was on the order of .4. In families in which both parents scored in the upper quartile for social impairment on the SRS, mean SRS score of offspring was significantly elevated (effect size 1.5). Estimated assortative mating explained approximately 30% of the variation in parent SRS scores. CONCLUSIONS: Children from families in which both parents manifest subthreshold autistic traits exhibit a substantial shift in the distribution of their scores for impairment in reciprocal social behavior, toward the pathological end. As has been previously demonstrated in children, heritable subthreshold autistic impairments are measurable in adults and appear continuously distributed in the general population.

Published 22 March 2005 in Biol Psychiatry, 57(6): 655-60.
Full-text of this article is available online (may require subscription).

© 2004-2008 Autism Research Today. All Rights Reserved.