Etiological influences on the stability of autistic traits from childhood to early adulthood: evidence from a twin study

Taylor, M. J., Gillberg, C. , Lichtenstein, P. and Lundström, S. (2017) Etiological influences on the stability of autistic traits from childhood to early adulthood: evidence from a twin study. Molecular Autism, 8, 5. (doi: 10.1186/s13229-017-0120-5) (PMID:28316769) (PMCID:PMC5351180)

Abstract

Background: Autism spectrum disorders (ASD) are persistent and lifelong conditions. Despite this, almost all twin studies focus on childhood. This twin study investigated the stability of autistic traits from childhood to early adulthood and explored the degree to which any stability could be explained by genetic or environmental factors. Methods: Parents of over 2500 twin pairs completed questionnaires assessing autistic traits when twins were aged either 9 or 12 years and again when twins were aged 18. Bivariate twin analysis assessed the degree of phenotypic and etiological stability in autistic traits across this period. Genetic overlap in autistic traits across development was also tested in individuals displaying a broad ASD phenotype, defined as scoring within the highest 5% of the sample. Results: Autistic traits displayed moderate phenotypic stability (r = .39). The heritability of autistic traits was 76–77% in childhood and 60–62% in adulthood. A moderate degree of genetic influences on childhood autistic traits were carried across into adulthood (genetic correlation = .49). The majority (85%) of the stability in autistic traits was attributable to genetic factors. Genetic influences on autistic traits were moderately stable from childhood to early adulthood at the extremes (genetic correlation = .64). Conclusions: Broad autistic traits display moderate phenotypic and etiological stability from childhood to early adulthood. Genetic factors accounted for almost all phenotypic stability, although there was some phenotypic and etiological instability in autistic traits. Thus, autistic traits in adulthood are influenced by a combination of enduring and unique genetic factors.

• Item Type: Articles
• Additional Information: CATSS is funded by the Swedish Research Council for Health, Working Life and Welfare, and the Swedish Research Council. We acknowledge support from the Swedish Research Council through the Swedish Initiative for Research on Microdata in the Social and Medical Sciences (SIMSAM) framework (grant no. 340-2013-5867).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Gillberg, Professor Christopher
• Authors: Taylor, M. J., Gillberg, C., Lichtenstein, P., and Lundström, S.
• College/School: College of Medical Veterinary and Life Sciences > School of Health & Wellbeing > Mental Health and Wellbeing
• Journal Name: Molecular Autism
• Publisher: BMC
• ISSN: 2040-2392
• ISSN (Online): 2040-2392
• Copyright Holders: Copyright © 2017 The Authors
• First Published: First published in Molecular Autism 8:5
• Publisher Policy: Reproduced under a Creative Commons License