Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Email this article to a Colleague Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to My Articles & Searches Download to citation manager Citing Articles via HighWire Citing Articles via Google Scholar Articles by Kates, W. R. Articles by Pearlson, G. D. Search for Related Content PubMed Citation Articles by Kates, W. R. Articles by Pearlson, G. D. Child/Adolescent Psychiatry Autism Genetics MRI Related Article

Neuroanatomic Variation in Monozygotic Twin Pairs Discordant for the Narrow Phenotype for Autism

OBJECTIVE: The broader autism phenotype includes relatives of individuals with autism who display social and language deficits that are qualitatively similar to those of autism but less severe. In previous studies of monozygotic twins discordant for autism, more than 75% of the twins without autism displayed the broader phenotype. Differences in neuroanatomy between discordant monozygotic twins might be associated with the narrow and broader behavioral phenotypes. The authors examined the relationship of twin pair differences in clinical phenotype to differences in neuroanatomic phenotype. METHOD: The subjects were 16 monozygotic twin pairs between the ages of 5 and 14 years and 16 matched singleton comparison subjects. Seven twin pairs were clinically concordant and nine twin pairs were clinically discordant for strictly defined autism. After magnetic resonance imaging, a semiautomated procedure was applied to images in which the brain tissue was subdivided into neurofunctional regions and segmented into gray, white, and ventricular compartments. RESULTS: Both the concordant and discordant twin pairs exhibited concordance in cerebral gray and white matter volumes. However, only the clinically concordant pairs exhibited concordance in cerebellar gray and white matter volumes. Within the discordant twin pairs, both the twins with autism and their co-twins exhibited frontal, temporal, and occipital white matter volumes that were lower than those of the comparison subjects. CONCLUSIONS: These findings support the role and the limits of genetic liability in autism. Continuing to clarify the neuroanatomic pathways in autistic spectrum disorders could illuminate the etiology of autism and, ultimately, contribute to treatments.

Related Article:

In This Issue
Am J Psychiatry 2004 161: A86. [Full Text] [PDF]

This article has been cited by other articles:

				S. H. Mostofsky, S. K. Powell, D. J. Simmonds, M. C. Goldberg, B. Caffo, and J. J. Pekar Decreased connectivity and cerebellar activity in autism during motor task performance Brain, September 1, 2009; 132(9): 2413 - 2425. [Abstract] [Full Text] [PDF]

				S. R. Mitchell, A. L. Reiss, D. H. Tatusko, I. Ikuta, D. B. Kazmerski, J.-A. C. Botti, C. P. Burnette, and W. R. Kates Neuroanatomic Alterations and Social and Communication Deficits in Monozygotic Twins Discordant for Autism Disorder Am J Psychiatry, August 1, 2009; 166(8): 917 - 925. [Abstract] [Full Text] [PDF]

				F. Vitaro, M. Brendgen, and L. Arseneault The discordant MZ-twin method: One step closer to the holy grail of causality International Journal of Behavioral Development, July 1, 2009; 33(4): 376 - 382. [Abstract] [PDF]

				C. Limperopoulos, H. Bassan, N. R. Sullivan, J. S. Soul, R. L. Robertson Jr, M. Moore, S. A. Ringer, J. J. Volpe, and A. J. du Plessis Positive Screening for Autism in Ex-preterm Infants: Prevalence and Risk Factors Pediatrics, April 1, 2008; 121(4): 758 - 765. [Abstract] [Full Text] [PDF]

				H. Yamasue, M. Ishijima, O. Abe, T. Sasaki, H. Yamada, M. Suga, M. Rogers, I. Minowa, R. Someya, H. Kurita, et al. Neuroanatomy in monozygotic twins with Asperger disorder discordant for comorbid depression Neurology, August 9, 2005; 65(3): 491 - 492. [Full Text] [PDF]

				M. K. Belmonte, G. Allen, A. Beckel-Mitchener, L. M. Boulanger, R. A. Carper, and S. J. Webb Autism and Abnormal Development of Brain Connectivity J. Neurosci., October 20, 2004; 24(42): 9228 - 9231. [Full Text] [PDF]

				Brain-Volume Differences in Autistic Children Journal Watch Psychiatry, April 22, 2004; 2004(422): 3 - 3. [Full Text]

Get information about faster international access.

Privacy Policy

Copyright © 2004 American Psychiatric Association. All rights reserved.

Home | Search | Current Issue | Past Issues | Subscribe | All APPI Journals | Help | Contact Us